Category Archives: Weeds

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Weeds

Shining Cranesbill | Geranium lucidum L.

March 10, 2017 Raj Randhawa

California Pest Rating for

Geranium lucidum L.: Shining cranesbill

Geraniales: Geraniaceae

Pest Rating: A | Proposed Seed Rating: R

PEST RATING PROFILE

Initiating Event:

Geranium lucidum was first observed in 1998 in wildland behind University of California, Berkeley campus in Alameda County. It has been reported in Humboldt and Alameda counties between 2011 and 2016 (CalFlora). Since 2013, it is regulated as a noxious weed in the states of Oregon and Washington (APHIS Weed Risk Assessment 2013). In California, this species has a temporary rating of Q. Due to its recent finds in the environment, a pest rating proposal is required to assign a permanent rating.

History & Status:

Background: Geranium lucidum is an herbaceous annual plant with stems up to 35 cm long, brittle, fleshy, hairless and red. The leaves are round to kidney-shaped, glossy, and palmately-lobed to about two thirds of their depth. This species is native to Europe, western Asia and North Africa. It is common in Great Britain and Ireland. It has been introduced to North America as a garden plant, particularly in the Pacific Northwest and has become naturalized there. It is often seen in association with the related Geranium robertianum, which is classified as a noxious weed in Washington (Revolvy.com).

Geranium lucidum favors steep dry banks, rocky walls and other fairly barren sites. Alkaline to neutral soils are preferred but it can also grow on moderately acidic soils (First nature). This species is self-compatible, reproduces by seeds, and forms dense carpets of seedlings in invaded habitats (Dannehy, 2011). This plant spread from Oregon to Washington in contaminated nursery plants. Geranium lucidum forms a seed bank that persists for more than a year (APHIS WRA 2013).

Worldwide Distribution: Geranium lucidum is native to Europe, northern Africa, the Middle East, the Caucasus, Central Asia and the temperate Himalaya. In the United States, it was first collected in 1971 from a cow pasture in Oregon. It has naturalized in parts of Oregon and Washington.

Official Control: Geranium lucidum is listed as a class B noxious weed in Washington (Kings County Noxious Weeds)

California Distribution: Geranium lucidum has been observed growing in some areas of Alameda, Del-Norte and Humboldt counties (Cal Flora).

California Interceptions: Geranium lucidum has not been detected through regulatory pathways by CDFA (PDR Database).

The risk Geranium lucidum, the shining geranium, would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: It is estimated that 54 percent of United States is suitable for the establishment of Geranium lucidum based on plant hardiness zones, annual precipitation and Koppen-Geiger climate classes. This species can grow in plant hardiness zones 6-9 and in areas with 10-100 plus inches of annual precipitation. California’s climate is very similar and favorable for its growth and spread (USDA ARS Interactive map). Additionally, it can grow in oak woodlands, dry coniferous and riparian forests, roadsides, pastures and shady areas. (Dennehy et.al 2011). It receives a High (3) in the category.

Evaluate if the pest would have suitable hosts and climate to establish in California:

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: Geranium lucidum does not require any host but grows wherever ecological conditions are favorable. It receives a High (3) in this category.

Evaluate the host range of the pest:

– Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Geranium lucidum is self-compatible and reproduces by seed. Seeds are dispersed by recoiling of the awn (Dennehy, 2011). Seeds can travel in still air up to 20 feet (Salisbury 1961). Seeds have water impermeable seed coat and can remain viable for more than one year (Van Asseche and Vandelook, 2006). Propagules are likely to disperse in yard trash dumped alongside roads and through mud attached to people, domesticated animals and vehicles. Primary long distance dispersal can be on the feet of deer or livestock. This species is spreading from Oregon to Washington in contaminated nursery plants (Dennehy 2011). It receives a High (3) in this category.

Evaluate the natural and artificial dispersal potential of the pest:

Score: 3

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

– High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Geranium lucidum is listed as a quarantine pest in the state of Washington and is prohibited to move it or sell it within the state. Public and private landowners are required to control this plant on their properties. (Kings county noxious weed program). Trade of nursery grown plants could be impacted in California because this species can contaminate nursery stock. Its extreme abundance can have an exclusionary effect because it prohibits growth of other vegetation (Dennehy, 2011). In California, it may reduce the forage value of unimproved pastures that occur on hillside where cultivation is difficult. It receives a High (3) in this category.

Evaluate the economic impact of the pest to California using the criteria below:

Economic Impact: B, C, D

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 3

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact: Geranium lucidum can dominate habitat understories and can eliminate their structural diversity. It also has the ability to displace native species and prevents new growth. This species is considered a major threat to the integrity of oak woodlands in United States. It is a major weed in natural ecosystems. (Dennehy, 2011). Because Geranium lucidum forms extensive stands that outcompete spring wildflowers, it is likely to impact understory threatened and endangered species (ODA, 2013). It could also make habitat restoration for rare species difficult.

It receives a High (3) in this category

Evaluate the environmental impact of the pest on California using the criteria below:

Environmental Impact: A, C, D

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact Score: 3

– Low (1) causes none of the above to occur.

– Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

**Consequences of Introduction to California for Geranium Lucidum, Shining geranium: High (15)**

Add up the total score and include it here:

-Low = 5-8 points

-Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Geranium lucidum has been found growing in the environment of Alameda, Del-Norte and Humboldt counties of California and receives a Low (-1) in this category.

Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included:

Score: -1

-Not established (0) Pest never detected in California, or known only from incursions.

–Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

-Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: High (14)

Uncertainty:

Geranium lucidum is a high risk weed that can establish faster due to natural dispersal, unintentional dispersal by people and through the nursery trade. Once established, it can be impossible to eliminate. Because it is getting difficult to eradicate from heavily infested areas of Oregon and Washington, early detection in California can help it from spreading to new areas.

In spite of notable risks, a small nursery based in Kentfield, Marin County is selling Geranium lucidum seeds for planting in home garden (Geraniaceae.com). It is uncertain if these seeds are sold to grow Geranium lucidum for medicinal purpose.

Conclusion and Rating Justification:

Geranium Lucidum has been found in the environment of California and would likely have significant economic and environmental impacts if it gets established in the state. An “A”-rating is justified.

References:

CalFlora: Geranium lucidum. Interactive distribution map: Distribution by the county. http://www.calflora.org/cgi-bin/species_query.cgi?where-taxon=Geranium+lucidum
Dennehy, C., E. R. Alverson, H. E. Anderson, D. R. Clements, R. Gilbert, and T. N. Kaye. 2011. Management Strategies for Invasive Plants in Pacific Northwest Prairies, Savannas, and Oak Woodlands. Northwest Science 85(2):329-351.
First Nature. Geranium lucidum – Shining Geranium http://www.first-nature.com/flowers/geranium-lucidum.php
Kings County, WA 2017. Noxious Weeds: Shining geranium. http://www.kingcounty.gov/services/environment/animals-and-plants/noxious-weeds/weed-identification/shiny-geranium.aspx
ODA 2013. Shiny geranium (Geranium lucidum) Oregon Department of Agriculture (ODA), Salem, Oregon. https://www.oregon.gov/ODA/shared/Documents/Publications/Weeds/ShinyGeraniumProfile.pdf
Online sale Geranium lucidum plants through a company based in Kentfield, CA http://geraniaceae.com/cgi-bin/listPlants.cgi?major=Geraniums&minor=Annuals
Pest and Damage Record Database, Plant Health and Pest Prevention Services, CA Department of Food and Agriculture. Assessed Date: 01/12/2016
Revolvy Llc: Geranium lucidum https://www.revolvy.com/main/index.php?s=Geranium%20lucidum
Salisbury, E. 1961. Weeds and Aliens. Collins, London. 384 pp.
USDA APHIS Risk Assessment: Geranium Lucidum https://www.aphis.usda.gov/plant_health/plant_pest_info/weeds/downloads/wra/Geranium_lucidum_WRA.pdf
USDA ARS Interactive map. http://planthardiness.ars.usda.gov/phzmweb/interactivemap.aspx
Van Assche, J. A., and F. E. A. Vandelook. 2006. Germination ecology of eleven Species of Geraniaceae and Malvaceae, with special reference to the effects of drying seeds. Soil Seed Science 16:283-290.

Responsible Party:

Raj Randhawa, Senior Environmental Scientist; California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 654-0312; plant.health[@]cdfa.ca.gov.

Pest Rating: A | Proposed Seed Rating: R

Posted by ls

Weeds

West Indian woodnettle | Laportea aestuans

February 22, 2017 Javaid Iqbal

California Pest Rating for

West Indian Woodnettle | Laportea aestuans

Family: Urticaceae

Pest Rating: C | Proposed Seed Rating: N/A

PEST RATING PROFILE

Initiating Event:

Laportea aestuans currently has a Z rating, and was recently found in San Luis Obispo County. A permanent pest rating proposal is required to support an official pest rating.

History & Status:

Background: Laportea aestuans is an annual herb belongs to the nettle family growing up to 1 m tall. It has fleshy and slightly woody stem with both stinging and nonstinging hairs. Leaves are alternate and broadly oval with serrated margins; petiole is reddish in color. The tiny flowers are greenish yellow in color and occur in clusters on a 4-10 cm long peduncle². This plant can grow from sea level up to 1300 m altitude. It occurs along roads and in other disturbed locations in forest or woodland areas. It grows in partial shade and sometimes in rock crevices¹.

Laportea aestuans is native to tropical Africa. It is widely distributed throughout the western and eastern hemisphere tropics and subtropics, including Central America, the West Indies, India, Sumatra and Java. In the US, it can be found in California and Florida¹.

Laportea aestuans is considered an agricultural weed because of its invasive characteristics, but it is used as food source and in traditional medicine in Africa. It hosts root-knot nematode (Meloidogyne spp.), a pest of banana plantations which is “A” rated and a quarantine pest in California. It is a known host of African cassava mosaic virus, an important pest of the major African food crop Cassava (Manihot esculenta)^{1, 2}.

Worldwide Distribution: Laportea aestuans is widely distributed in tropical Africa, from Senegal eastward to Eritrea and southward to Angola, Zimbabwe and Mozambique, and in Madagascar. It also reported in tropical Asia and tropical America².

Official Control: Laportea aestuans is not declared or considered noxious by any State government authorities⁵.

California Distribution: It was introduced to California and collected as greenhouse weed in San Bernardino and Riverside counties³. It was also growing in the UC Riverside Botanical Garden in 1995.

California Interceptions: Laportea aestuans was intercepted three times between January, 1990 up to December, 2016. One specimen recently was collected in San Luis Obispo county on January 6, 2017 through regulatory pathways (Pest and Damage Report Database, CA Department of Food and Agriculture)⁴.

Consequences of Introduction:

1) Climate/Host Interaction: Laportea aestuanswas collected in San Bernardino and Riverside counties. It may remain a weed of greenhouses. Therefore, Laportea aestuans receives a Low (1) in this category.

Evaluate if the pest would have suitable hosts and climate to establish in California:

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range Laportea aestuans do not require any one host, but grows wherever ecological conditions are favorable. It receives a High(3) in this category.

Evaluate the host range of the pest.

– Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Laportea aestuans reproduces only by seed. Seeds are dispersed by animals, water runoff and by the movement of contaminated agricultural tools. It receives at Medium (2) in this category.

Evaluate the natural and artificial dispersal potential of the pest.

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

– High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Laportea aestuans had not yet had an impact on agricultural lands and future possible impacts are unknown. It could possibly effect the normal cultural practices by growing in dense stands. It receives a Low (1) in this category.

Evaluate the economic impact of the pest to California using the criteria below.

Economic Impact: D

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 1

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact: Laportea aestuans had not spread widely only found in greenhouse situation in California. If it does spread, it might trigger new treatments by land managers. It receives a Medium (2) in this category.

Evaluate the environmental impact of the pest on California using the criteria below.

Environmental Impact: D

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact: Score: 2

– Low (1) causes none of the above to occur.

– Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Laportea aestuans (West Indian woodnettle): Medium (9)

–Low = 5-8 points

–Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Laportea aestuans has been reported only in greenhouses in San Bernardino and Riverside counties³. It receives a Low (-1) in this category.

Score: -1

-Not established (0) Pest never detected in California, or known only from incursions.

–Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

-Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: Low (8)

Uncertainty:

Laportea aestuans entered California and appeared in greenhouses habitat. So, there is low uncertainty.

Conclusion and Rating Justification:

Conclusions of the harm(s) associated with this pest to California using all of the evidence presented above: Proposed Rating: based on the score listed above the pest is a low risk. A “C” rating is recommended.

References:

Brink, M., 2009. Laportea aestuans (L.) Chew. Record from PROTA4U. Brink, M. & Achigan-Dako, E.G. (Editors). PROTA (Plant Resources of Tropical Africa), Wageningen, Netherlands. Accessed January 19, 2017 http://www.prota4u.org/protav8.asp?p=Laportea+aestuans

Derek Arakaki and Christopher Lao. 2012. Pest advisory No. 12-02. Dept. of Agriculture Hawaii. Accessed January 19, 2017 https://hdoa.hawaii.gov/pi/files/2013/01/Laportea-aestuans-NPA.pdf

Calflora: Information on California plants for education, research and conservation, with data contributed by public and private institutions and individuals, including the Consortium of California Herbaria. 2016. Berkeley, California. Accessed January 19, 2017 https://www.calflora.org/cgi-bin/species_query.cgi?w here-calrecnum=8755

Pest and Damage Record Database, California Department of Food and Agriculture, Plant Health and Pest Prevention Services. Accessed 1-19-2017. http://phpps.cdfa.ca.gov/user/frmLogon2.asp

USDA Phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD). Accessed January 19, 2017 https://pcit.aphis.usda.gov/pcit/

Responsible Party:

Javaid Iqbal, California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 403-6695; plant.health[@]cdfa.ca.gov.

Pest Rating: C | Proposed Seed Rating: N/A

Posted by ls

Weeds

English Ivy, Irish Ivy & Algerian Ivy | Hedera spp.

February 22, 2017 Dean Kelch

California Pest Rating for

**English Ivy, Irish Ivy & Algerian Ivy | Hedera spp.**

Pest Rating: None

PEST RATING PROFILE

Initiating Event:

This plant is subject to a petition to the Secretary to list English ivy (Hedera helix) as a noxious weed.

History & Status:

True ivies (Hedera spp.) are vining, evergreen plants with dark, glossy, (generally) lobed leaves. When they reach something to climb on, they grow upwards using innumerable adventitious roots that sprout from the stems. After growing upward into sun, the plant changes it growth form, producing unlobed leaves and rigid stems that project from the framework. These fertile stems produce many small green flowers in compound umbels. The fruits are black berries (yellow in H. helix subsp. poetarum) that are generally dispersed by birds, sometimes to a great distance from the mother plant. Although a single ivy plant can carpet a ~0.1 hectare area or take over a tree, it is the bird-dispersed seed that account for most of the continuous spread of the plants.

The various species of ivy are difficult to distinguish and they sometimes hybridize. Even in their home range, widespread cultivation of non-native species or cultivars make identification difficult. The most common species in cultivation on the West Coast are English ivy (H. helix), Irish ivy (H. hibernica) and Algerian ivy (H. algeriensis, synonym H. canariensis). They can be distinguished by the types of hairs on the underside of the leaves, as well as by their chromosome number. Nevertheless, because of confusion between the species, all three will be treated together.

Ivies are popular ground covers in gardens, where they can dominate large areas with a weed resistant mat. Many cultivars have been developed over the years and some gardeners form collections of the various forms. As pot plants, they are often trained over frameworks into topiaries.

Worldwide Distribution: Ivies are widespread throughout Eurasia, northern Africa and the Canary Islands (Hedera algeriana). As adventives, ivies are widespread in forested temperate and warm temperate areas of the world. In the United States, ivies have been found as introductions in all western, all eastern and all southern states.

Official Control: Ivies are listed as official weeds in Oregon and Washington. In California, some State Parks and other land management agencies have instituted ivy control in lands under their jurisdiction.

California Distribution: Aside from frequent usage in gardens, ivies are adventive in much of the state in the understory of forests. Ivies are only lacking in the hotter, drier areas.

California Interceptions: Ivies have been collected over 350 times in California, although many of these collections represent plants persisting from cultivation.

The risk ivies would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Evaluate if the pest would have suitable hosts and climate to establish in California.

Risk is High (3) as the plant is naturalized in many localities in CA. It prefers the north where there are extensive forests and higher rainfall, but ivies have proved themselves capable of spreading under favorable conditions (e.g., along rivers and creeks) in many areas of California. In Washington, Irish ivy is more invasive than English ivy and much more invasive than Algerian ivy. However, this relationship may differ in other parts of the West Coast. English ivy may be more invasive in California.

Score: 3

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: Evaluate the host range of the pest.

Risk is High (3) as weeds do not require any one host, but grow wherever ecological conditions are favorable.

Score: 3

– Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Evaluate the natural and artificial dispersal potential of the pest.

Risk is Medium (2). The plants produce large vines that can dominate significant areas. Mature plants can form thousands of bird-dispersed seeds per year.

Score: 2

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

– High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Evaluate the likely economic impacts of the pest to California using the criteria below.

Risk is Medium (2) as the plants can lower timber crop value by interfering with tree seedling establishment, damage adult trees by overgrowing them and poison livestock if grazed extensively.

Economic Impact Score: 2

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact: Evaluate the environmental impact of the pest on California using the criteria below.

Risk is High (3) as the plant can dominate forest understories and forest margins, excluding native plants and lowering biodiversity, and can exclude cultural plants from a landscape. They can also affect threatened or endangered species by overgrowing their food plants, e.g., covering rocky slopes supporting the host plant of the San Bruno elfin butterfly (Callophrys mossii bayensis).

Environmental Impact. Score: 3

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

– Low (1) causes none of the above to occur.

– Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for true ivies:

Add up the total score and include it here. High (13)

–Low = 5-8 points

–Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included. (-3)

–Not established (0) Pest never detected in California, or known only from incursions.

–Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

–Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

–High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

7) The final score is the consequences of introduction score minus the post entry distribution and survey information score: (10)

Uncertainty:

The dry climate has limited ivies’ spread in CA. However, they are still spreading in shady forest and riparian habitats, as they are in OR & WA.

Conclusion and Rating Justification:

These are very bad forest weeds. The magnitude of their planted and escaped populations preclude regional control and ensure their continued widespread distribution. Currently, classifying true ivies as noxious weeds would not significantly impact its current or future distribution, as they would continue to spread despite regulation. Many birds feed on ivy berries and can travel long distances from existing residential and naturalized sources.

Similar invasive and widespread plants have been given a C rating. Only a small number of noxious weeds are C rated weeds; However, the California Food and Agriculture Code section 5004 states that “In determining whether or not a species shall be designated a noxious weed for the purposes of protecting silviculture or important native plant species, the director shall not make that designation if the designation will be detrimental to agriculture.” As ivies are largely weeds of forest areas and are mainstays of the nursery agricultural sector, they would fall under this stricture.

Classifying Hedera spp. as noxious weeds would harm agriculture by preventing the sale of popular nursery plants. At this point in their invasion curve, newly planted ivies represent a very small contribution to the existing populations. Any regulation of this plant would have little or no consequence in limiting its invasiveness or reducing the costs of ivy management. Therefore, given the economic and horticultural importance, no rating is recommended for English ivy, Irish ivy and Algerian ivy at this time.

References:

Ackerfield J. & J. Wen. 2002. A morpholometric analysis of Hedera L. and its taxonomic implications. Adansonia 24:197–212.

Aizpuru I., C. Aseguinolaza, P. M. Uribe-Echebarría, P. Urrutia, e I. Zorrakín. 2003. Claves ilustradas de la flora del País Vasco y Territorios Limítrofes. Eusko Jaurlarizaren. Vitoria-Gasteiz, Spain.

Baldwin, B. G., D. H. Goldman, D. J. Keil, R. Patterson, T. J. Rosatti, and D. H. Wilken, editors. 2012. The Jepson Manual: Vascular Plants of California, second edition. University of California Press, Berkeley, CA.xw

Bramwell, D & Z. Bramwell. 1994. Flores Silvestres de las Islas Canarias. Editorial Rueda. Madrid, Spain.

Consortium of California Herbaria (ucjeps.berkeley.edu/consortium/).

King County: English Ivy, Hedera helix. Accessed 2/15/2017. http://www.kingcounty.gov/services/environment/animals-and-plants/noxious-weeds/weed-identification/english-ivy.aspx

Midori M. C., S. H. Reichard, & C. W. Hamilton. 2006. Prevalence of different horticultural taxa of ivy (Hedera spp., Araliaceae) in invading populations. Biol. Invasions 8:149-157.

USDA Plants; Hedera helix. Accessed 2/15/2017: https://plants.usda.gov/core/profile?symbol=HEHE

Vargas P., H. A. McAllister, C. Morton, S. L. Jury & M. J. Wilkinson. 1999. Polyploid speciation in Hedera (Araliaceae): phylogenetic and biogeographic insights based on chromosome counts and ITS sequences. Plant Systematics and Evolution 219:165–179.

Webb, D. A. 1968. Hedera in Flora Europaea Vol. 2: Rosaceae to Umbelliferae. T. G. Tutin, V. H. Heywood, N. A. Burges, D. H. Valentine, S. M. Walters, & D. A. Webb, eds. Cambridge University Press. United Kingdom.

Responsible Party:

Dean G. Kelch, Primary Botanist; California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 403-6650; plant.health[@]cdfa.ca.gov

Pest Rating: None | Proposed Seed Rating: None

Posted by ls

Weeds

Barbwire Russian thistle | Salsola gobicola

February 16, 2017 Javaid Iqbal

California Pest Rating

Barbwire Russian thistle | Salsola gobicola

Family: Chenopodiaceae

Pest Rating: B | Proposed Seed Rating: R

PEST RATING PROFILE

Initiating Event:

Salsola gobicola has an internal CDFA rating of “Q”. A permanent pest rating proposal is required to support an official pest rating.

History & Status:

Background: Salsola gobicola is an annual herbaceous dicot that can grow 1.5 m tall¹. The genus Salsola belongs to the tribe Salsoleae of the family Amaranthaceae. Salsola means “salty” in Latin, referring its tolerance for salty soils. This genus has very large number of species, but only a few species appears as weeds in North America. These species includes Salsola tragus (probably the most widespread), Salsola collina (mainly east of the Rocky Mountains), Salsola paulsenii (primarily in deserts), Salsola kali (restricted to ocean shores) and Salsola australis (mainly in California, South Africa and Australia). Polyploid hybrids include Salsola x gobicola (a cross of S. tragus and S. paulsenii) that is known in the western USA and central Asia, and Salsola x ryanii (a cross of S. tragus and S. australis), known only from California⁴.

Salsola gobicola appears where the parent species overlap, in central Asia and the western USA. It is well distributed in sandy (120–2200 m) places in California. It has spreading to ascending stems and opposite to alternate, gray green to yellow green leaves. It has small flower, a green calyx and sepals’ soft to spiny. The flowering time is July to October⁶.

Worldwide Distribution: The genus Salsola is reported widespread in Europe and Asia. Salsola gobicola is only reported outside California in Utah and Mexico⁶.

Official Control: Salsola gobicola is not known to be under official control in any States or nations⁹.

California Distribution: It is reported form Imperial, Inyo, Kern, Lassen, Los Angeles, Mono, Riverside, San Bernardino, Riverside, San Luis Obispo and Tulare counties^{2, 7}.

California Interceptions: Salsola gobicola was intercepted three times between January 2010 and December 2116 by CDFA border protection stations. There were several vouchers were submitted before 2000’s⁸.

The risk Salsola gobicola (Barbwire Russian thistle) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Salsola gobicola is established large sandy area in California and still spreading². Therefore, it receives a High (3) in this category.

Evaluate if the pest would have suitable hosts and climate to establish in California:

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: Salsola gobicola do not require any one host, but grow wherever ecological conditions are favorable. It receives a High (3) in this category.

Evaluate the host range of the pest. Score: 3

Low (1) has a very limited host range

Medium (2) has a moderate host range

High (3) has a wide host range

3) Pest Dispersal Potential: Seed spreading via tumbling mature plants with air current is very common in this genus. The mature plants contain thousands of seeds ready to germinate in sandy, salty dry soil condition. Seed are also transported to long distances by cattle and human transport systems. It receives a High (3) in this category

Evaluate the natural and artificial dispersal potential of the pest.

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

– High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Salsola gobicola could invades the cropland, especially spring wheat by growing in dense stands. It decreases crop yield and can lower the crop value. It displaces both native plants and other plants which could negatively change normal cultural practices. It receives a High (3) in this category.

Evaluate the economic impact of the pest to California using the criteria below.

Economic Impact: A, B, D

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 3

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact: Salsola gobicola is likely to trigger new chemical treatments by ranchers and land managers. A study shows that Salsola gobicola contributes population decline and had negative effect on the habitat of these two federally listed endangered species, the Eureka Valley dune grass (Swallenia alexandrae) and the Eureka Valley evening primrose (Oenothera californica ssp. Eurekensis)^3,5. It may also effect the rare taxa Mariposa lupine (Lupinus citrinus), Antioch dunes evening primrose (Oenothera deltoids spp. howellii) and grassland species such as California round leaved filaree (California macrophylla). The plant can disrupt natural communities. Salsola gobicola receives a High (3) in this category.

Evaluate the environmental impact of the pest on California using the criteria below.

Environmental Impact: A B, C, D

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact Score: 3

– Low (1) causes none of the above to occur.

– Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Salsola gobicola (Barbwire Russian thistle): High (15)

–Low = 5-8 points

–Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Salsola gobicola has been reported in 12 counties in California. It receives a Medium (-2) in this category.

Score: -2

-Not established (0) Pest never detected in California, or known only from incursions.

-Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

–Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: High (13)

Uncertainty:

Salsola gobicola has been known in California for decades and it has proved highly invasive. So, there is low uncertainty.

Conclusion and Rating Justification:

Conclusions of the harm(s) associated with this pest to California using all of the evidence presented above: Proposed Rating: based on the score listed above the pest is a high risk weed with a distribution in at least 12 counties. A “B” rating is recommended, as the plant is invasive, but could spread further.

References:

Annual report 2009. Plant pest Diagnostics center. California Department of Food and Agriculture. Accessed January 05, 2017 https://www.cdfa.ca.gov/plant/ppd/PDF/PPDC2009.pdf

Calflora: Information on California plants for education, research and conservation, with data contributed by public and private institutions and individuals, including the Consortium of California Herbaria. 2016. Berkeley, California. Accessed January 05, 2017 https://www.calflora.org/cgi-bin/species_query.cgi?where-calrecnum=12004

Chow, Elaine K. Ph D. 2016. Dynamics of Native and Invasive Non-native Plant Species in Desert Sand Dunes of Eureka Valley, Death Valley National Park. UC, DAVIS. 149 pages; 10182745. Accessed January 05, 2017 http://gradworks.umi.com/10/18/10182745.html

Invasive Species Compendium: Distribution maps for plant pests, Accessed January 05, 2017 http://www.cabi.org/cpc/datasheet/50297

Jane Cipra and Kelly Fuhrmann, 2012. Understanding endangered plant species population changes at Eureka Dunes, Death Valley National Park. Park science Volume 29. Accessed January 05, 2017 https://www.nature.nps.gov/parkscience/Archive/PDF/Article_PDFs/ParkScience29(1)SpringSummer2012_62-68_CipraFuhrmann_2874.pdf

Jepson Baldwin, B. G., D. H. Goldman, D. J. Keil, R. Patterson, T. J. Rosatti, and D. H. Wilken, editors. 2012. The Jepson manual: vascular plants of California, second edition. University of California Press, Berkeley. Accessed January 05, 2017 http://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=82452

Roskov Y., Abucay L. Orrell T. Nicolson D. eds. 2015. The University of Georgia Center for invasive species and ecosystem health. Accessed January 05, 2017 https://www.eddmaps.org/Species/subject.cfm?sub=75312

Pest and Damage Record Database, California Department of Food and Agriculture, Plant Health and Pest Prevention Services. http://phpps.cdfa.ca.gov/user/frmLogon2.asp

USDA Phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD). Accessed January 05, 2017 https://pcit.aphis.usda.gov/pcit/

Responsible Party:

Javaid Iqbal, California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 403-6695; plant.health[@]cdfa.ca.gov.

Comment Format:

♦ Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

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Pest Rating: B | Proposed Seed Rating: R

Posted by ls

Weeds

Ward’s Weed | Carrichtera annua

February 1, 2017 Javaid Iqbal

California Pest Rating for

Ward’s Weed | Carrichtera annua

Family: Brassicaceae

Pest Rating: A | Proposed Seed Rating: R

PEST RATING PROFILE

Initiating Event:

Carrichtera annua was introduced in California in the early 2000’s and had no previous pest rating. A pest rating proposal is required to determine a permanent rating for this pest.

History & Status:

Background: Carrichtera annua is an annual member of the mustard family (Brassicaceae)¹. It is commonly known as Ward’s weed. It is a small, upright to spreading, short-lived herbaceous plant which can grow 5-40 cm tall. The stems, leaves and fruits are covered with bristly hairs³. Carrichtera annua can be easily distinguished from other members of the mustard family by its fruits and leaves. The fruits are globe-shaped with a curved oblong extension; the opposite leaves are bipinnately compound. The flower petals are pale yellowish and the sepals are hairy and lavender in color before the flower opens¹.

Carrichtera annua is native to the Mediterranean region. It has been accidentally introduced to Australia and southern California. Carrichtera annua is a serious weed of semi-arid rangelands of Australia where the average annual rainfall is 250 mm – 350 mm. It is a common plant of dry open and disturbed sites of grassland and shrub land. Carrichtera annua is known to invade grassland areas, especially areas degraded by overgrazing, where it replaces pasture plants³.

Worldwide Distribution: Carrichtera annua is native to the Mediterranean region and western part of Asia. It is reported in Algeria, Egypt, Libya, Morocco, Tunisia, Kuwait, Saudi Arabia, Cyprus, Egypt, Iran, Iraq, Israel, Jordan, Lebanon, Syria, Greece and Italy. It is widely naturalized in the inland regions of southern and central parts of Australia. It is also sparingly naturalized in Tasmania and parts of southern and central Queensland⁵.

Official Control: Carrichtera annua is not declared or considered noxious by any state government authorities⁷.

California Distribution: Carrichtera annua currently is known from a limited area of San Diego County.

California Interceptions: Only one PDR No 1559908 collected in San Diego on Feb 18, 2009 was found in the Pest and Damage Record Database by CDFA⁶. It was collected in 1979 in Salinas, Monterey County, CA (voucher: Johnson & Oliver s.n, CDFA).

The risk Carrichtera annua (Ward’s weed) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: The plant has adapted to a wide area in its native range and is highly invasive in areas of Australia ecologically similar to California. Therefore Carrichtera annua receives a High (3) in this category.

Evaluate if the pest would have suitable hosts and climate to establish in California:

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: Carrichtera annua do not require any one host, but grow wherever ecological conditions are favorable. It receives a High (3) in this category.

Evaluate the host range of the pest.

– Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Carrichtera annua reproduces only by seed but it is capable of producing 30,000 seeds/mm²annually². These seeds are dispersed short distances by ants, foraging animals and human activity. They may be dispersed longer distances by vehicles, on larger animals and in contaminated agricultural produce. It receives a High (3) in this category.

Evaluate the natural and artificial dispersal potential of the pest.

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

– High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Carrichtera annua can form dense stands becoming the dominant herbaceous plant which could lower the crop yield and its value. It displaces both native plants and other rangeland species and could negatively change normal cultural practices. It is unpalatable to livestock. It receives a High (3) in this category.

Evaluate the economic impact of the pest to California using the criteria below.

Economic Impact: A, B, D, F

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 3

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact: Carrichtera annua is likely to trigger new chemical treatments by ranchers and land managers. The plant can dominate grasslands and roadsides, excluding native plants and lowering biodiversity. Rare taxa that might be affected include species such as showy Indian clover (Trifolium amoenum), CA filaree (California macrophylla), San Diego ambrosia (Ambrosia pumila), vernal pool species such as Burke’s goldfields (Lasthenia burkei), CA tiger salamander (Ambystoma californiense), and grazers such as tule elk (Cervuscanadensis nannodes). The plant can disrupt natural communities. Carrichtera annua receives a High (3) in this category.

Evaluate the environmental impact of the pest on California using the criteria below.

Environmental Impact: A B, C, D

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact: Score: 3

– Low (1) causes none of the above to occur.

– Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Carrichtera annua (Wards weed): High (15)

–Low = 5-8 points

–Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Carrichtera annua has been reported only in San Diego County and seems likely restricted to this area. It receives a Low (-1) in this category.

Score: -1

-Not established (0) Pest never detected in California, or known only from incursions.

–Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

-Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: High (14)

Uncertainty:

Uncertainty is low, as the plant has spread widely in the Mediterranean and South Australia. Carrichtera annua is been in California about 15 years ago and it is localized in a limited area.

Conclusion and Rating Justification:

An “A” rating is recommended, as the plant is invasive, but not yet widespread. There is still the chance to eradicate this plant from California.

References:

Jessie Vinje, 2008. Center for Natural Lands Management. Cal-IPC News page -9. Accessed January 03, 2017 http://www.cal-ipc.org/resources/news/pdf/Cal-IPC_News_Winter08.pdf

Julia Cooke, Dr.Julian Ash & Dr. Richard Groves. The Ecology of Ward’s weed. Australian National University. Accessed January 03, 2017 https://www.ecolsoc.org.au/files/pages/The%20Ecology%20of%20Ward’s%20Weed.pdf

Impact Assessment – Wards weed (Carrichtera annua) in Victoria. State Govt. Assessment page. Accessed January 03, 2017 http://vro.agriculture.vic.gov.au/dpi/vro/vrosite.nsf/pages/impact_wards_weed

Special edition of Environmental Weeds of Australia for Biosecurity Queensland. Accessed January 03, 2017 https://keyserver.lucidcentral.org/weeds/data/media/Html/carrichtera_annua.htm

S. National Plant Germplasm System Accessed January 03, 2017. https://npgsweb.ars-grin.gov/gringlobal/taxonomydetail.aspx?id=310895

Pest and Damage Record Database, California Department of Food and Agriculture, Plant Health and Pest Prevention Services. http://phpps.cdfa.ca.gov/user/frmLogon2.asp

USDA Phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD). Accessed January 03, 2017 https://pcit.aphis.usda.gov/pcit/

Responsible Party:

Javaid Iqbal, California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 403-6695; plant.health[@]cdfa.ca.gov.

Pest Rating: A | Proposed Seed Rating: R

Posted by ls

Weeds

Cytisus striatus: Portuguese Broom

January 31, 2017 Javaid Iqbal

California Pest Rating for

Cytisus striatus: Portuguese broom

Family: Fabaceae

Pest Rating: B | Proposed Seed Rating: P

PEST RATING PROFILE

Initiating Event:

Cytisus striatus has no rating in the past and it is growing widely in coastal areas especially in San Francisco, San Diego and Mendocino counties. It’s a B category noxious weed listed in Oregon. Due to this, a risk assessment of this known weed is critical to designate an official rating.

History & Status:

Background: Cytisus striatus is perennial, leguminous shrub known by the common names Portuguese broom, striated broom and hairy-fruited broom. It is six to nine feet tall with many slender stems that are silky-hairy when young and become more or less smooth when mature. Stems are covered sparsely by small leaves consisting of one to three leaflets. Pale yellow, pea-like flowers arise from the leaf axils singly or in pairs. Mature fruit pods are densely white-hairy, and each contains several seeds. Portuguese broom strongly resembles Scotch broom (Cytisus scoparius) which is invasive noxious weed in California. The main features that distinguish this species from Scotch broom are the paler yellow flower color, 8-10 versus 5-8 angles on the stem, and the densely white-hairy fruit pods of Portuguese broom³.

Cytisus striatus is the least common of the broom species in North America, occurring in California and Oregon. It currently occupies sixty-five acres in the Marin Headlands, Marin County, where it forms dense cover with one mature shrub per two square meters. It is found occasionally in other parts of the Bay area, and has been reported in Mendocino and San Diego counties¹. Its similarity to Cytisus scoparius may explain it lack of detection in central and south coastal counties¹.

Worldwide Distribution: Cytisus striatus is native to Morocco, Portugal and Spain. It is reported in a number of northwestern European countries including England, Scotland, Wales and France. It has also been introduced into California and Oregon in the USA and Argentina^3.

Official Control: Cytisus striatus is classified as a Category B noxious weed in Oregon⁶.

California Distribution: It was introduced to California in the 1960s as an erosion-control plant⁵. It is spreading in San Francisco Bay Area especially in Marin Headlands. It is also reported in Mendocino and San Diego counties, as well as in Yosemite National Park¹.

California Interceptions: Cytisus striatus has not been intercepted in California through regulatory pathways (Pest and Damage Report Database, CA Department of Food and Agriculture)¹⁰. It has been documented by State personnel.

The risk Cytisus striatus (Portuguese broom) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Cytisus striatus is established in the San Francisco Bay Area and is still spreading in other areas of California. Therefore, Cytisus striatus receives a High (3) in this category.

Evaluate if the pest would have suitable hosts and climate to establish in California:

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range Cytisus striatus do not require any one host, but grow wherever ecological conditions are favorable. It receives a High (3) in this category.

Evaluate the host range of the pest.

– Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Cytisus striatus reproduces 15,000 seeds per year⁴. Seeds are released ballistically from the pod, then further dispersed by ants, other animals and water runoff along the ground. Portuguese broom can resprout from its root crown when cut, particularly during the growing season³. It receives a High (3) in this category

Evaluate the natural and artificial dispersal potential of the pest.

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

– High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Cytisus striatus can invade cropland by growing in dense stands. It displaces both native plants and cultivated plants; this could negatively change normal cultural practices. It receives a Medium (2) in this category.

Evaluate the economic impact of the pest to California using the criteria below.

Economic Impact: A, D

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 2

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact: Cytisus striatus is capable of invading and establishing dense populations in coastal prairie, coastal scrub, oak savannah, and open-canopy woodlands⁷. Cytisus striatusis likely to trigger new chemical treatments by ranchers and land managers. Rare taxa that might be affected include grassland species such as showy Santa Cruz clover (Trifolium buckwestiorum), CA filaree (California macrophylla), Santa Cruz tarplant (Holocarpha macradenia) and Alameda whipsnake (Masticophis lateralis euryxanthus). The plant can disrupt natural communities. Cytisus striatus receives a High (3) in this category.

Evaluate the environmental impact of the pest on California using the criteria below.

Environmental Impact: A B, C, D

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact: Score: 3

– Low (1) causes none of the above to occur.

– Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Cytisus striatus (Portuguese broom): High (14)

–Low = 5-8 points

–Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Cytisus striatus has been reported only in San Francisco Bay Area, Mendocino, Yosemite National Park and San Diego Counties. It receives a Medium (-2) in this category.

Score: -2

-Not established (0) Pest never detected in California, or known only from incursions.

-Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

–Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (12)

Uncertainty:

Cytisus striatus entered California long ago, although it has not yet spread widely, there is nothing to stop it spreading in the appropriate habitats. So, there is low uncertainty.

Conclusion and Rating Justification:

Conclusions of the harm(s) associated with this pest to California using all of the evidence presented above: Proposed Rating: based on the score listed above the pest is a medium risk. A “B” rating is recommended, as the plant is invasive in 12 counties but has not spread as far as it is likely to without management.

References:

1. Alvarez, Maria. 2000. Cytisus striatus In: Bossard, Carla C.; Randall, John M.; Hoshovsky, Marc C., eds. Invasive plants of California’s wildlands. Berkeley, CA: University of California Press: 150-154. Accessed January 05, 2017. https://www.fs.fed.us/database/feis/plants/shrub/cytspp/all.html#4

2. Encyclopedia of Life. Hairy-fruited broom. Accessed January 05, 2017 http://eol.org/pages/703580/details

3. Invasive Plant of California’s Wildland. Cal-IPC News. Accessed January 05, 2017 http://www.cal-ipc.org/ip/management/ipcw/pages/detailreport.cfm@usernumber=40&surveynumber=182.php

4. Invasive weeds in Forest land. EC 1598-E September 2008 Oregon State University. Accessed January 05, 2017 http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/19804/ec1598-e.pdf

5. Inaturalist.org- hairy fruited broom – Accessed January 05, 2017 http://www.inaturalist.org/taxa/76598

6. Invasive Species information. Accessed January 05, 2017 http://www.weedcenter.org/resources/state.html

7. Michail Belov. 2005-2009 – Chile flora – Article. Accessed January 05, 2017 http://www.chileflora.com/Florachilena/FloraEnglish/HighResPages/EH0297.htm

8. Chater, A. O. & D. A. Webb. 1971. Orobanchein Flora Europaea Vol. 3: Diapensiaceae to Myoporaceae. T. G. Tutin, V. H. Heywood, N. A. Burges, D. H. Valentine, S. M. Walters, & D. A. Webb, eds. Cambridge University Press. United Kingdom.

9. Hrusa, F., B. Ertter, A. Sanders, G. Leppig, and E. Dean. 2002. Catalog of non-native vascular plants occurring spontaneously in California beyond those addressed in The Jepson Manual. Part I. Madroño 49: 61-98.

10. Pest and Damage Record Database, California Department of Food and Agriculture, Plant Health and Pest Prevention Services. http://phpps.cdfa.ca.gov/user/frmLogon2.asp

Responsible Party:

Javaid Iqbal, California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 403-6695; plant.health[@]cdfa.ca.gov.

Pest Rating: B | Proposed Seed Rating: P

Posted by ls

Weeds

Giant Hogweed | Heracleum mantegazzianum

January 11, 2017 Javaid Iqbal

California Pest Rating for

Giant Hogweed | Heracleum mantegazzianum

Family : Apiaceae

Pest Rating : A | Proposed Seed Rating: P

PEST RATING PROFILE

Initiating Event:

Giant hogweed is a federal listed noxious weed.

History & Status:

Background: Heracleum mantegazzianum, commonly called giant hogweed or cartwheel flower, is an herbaceous biennial or short-lived perennial that is noted for producing rapid and prodigious growth.Giant hogweed has over time escaped gardens and naturalized in roadside ditches, stream banks, fields, unused farmland,railroad track right-of-ways and along fences in a number of areas in North America, primarily the northeastern and northwestern U.S.plus parts of Canada. In the first year, this plant produces a large mound of coarse, compound, basal leaves (each to as much as 3′ long) with deeply cut leaflets. In the second year, the plant will rise up to 10-16′ tall topped by a gigantic, flat-topped, umbrella-like, compound umbel (2-4′ wide). Each umbel contains thousands of tiny white flowers. Plants bloom in late June. After flowering and fruiting, the plant dies. Each large flower umbel produce 20,000 seeds. Green stems are hollow and distinguished by white hairs and purple blotches. Giant hogweed is in the same genus as the cow parsnip (Heracleum maximum) which is native to North America³. It was brought to the U.S. in 1917 to an ornamental garden in New York. Giant hogweed is a USDA federally listed noxious weed and it is especially invasive in riparian and urban sites^5&6.

Large plants can restrict the access to rivers, trails, and paths; studies indicate that giant hogweed can negatively impact soil dynamics, fisheries, and other species in its nonnative habitats. Contact with plant sap can burn, blister, and scar to exposed skin. In severe cases the irritation leads to blistering that result in painful dark purple scars⁴.

Official Control: Giant hog weed is under official control in Colombia, Korea and in the Republic of Mexico⁷.

California Distribution: Giant hogweed has not yet been detected in California.

California Interceptions: None.

United States: Giant hogweed has been identified in 16 states since its inclusion on the Federal Noxious Weed list.These state Includes New York, Connecticut, the District of Columbia, Illinois, Maine, Maryland, Massachusetts, Michigan, Ohio, Oregon, Pennsylvania, Washington and Wisconsin⁴.

Worldwide Distribution: Giant hogweed is native to the Caucasus region of Eurasia and was introduced into Europe in the 1800s. It is reported in Austria, Czechoslovakia, Denmark, Finland, France, Germany, Georgia, Hungary, Ireland, Italy, the Netherlands, Norway, Sweden, Switzerland and in the United Kingdom. In Asia it is found in Central Russia and Iran. It is introduced into Australia and Canada as well^1&3.

Consequences of Introduction:

1) Climate/Host Interaction: Giant hogweed is well established in Oregon and Washington and is spreading there. These States have similar habitat to Northern Therefore, there is a high risk that it will establish in California. Giant hogweed receives a High(3) in this category.

Evaluate if the pest would have suitable hosts and climate to establish in California. Score(3)

-Low (1) not likely to establish in California; or likely to establish in very limited areas

-Medium (2) may be able to establish in a larger but limited part of California

–High (3) likely to establish a widespread distribution in California

2) Pest Host Range: Giant hogweeds do not require any one host, but grow wherever ecological conditions are favorable. It receives a High(3) in this category.

Evaluate the host range of the pest: Score:(3)

-Low (1) has a very limited host range

-Medium (2) has a moderate host range

-High (3) has a wide host range

3) Pest Dispersal Potential: Giant hogweed can produce up to 20,000 seeds, allowing it to spread quickly and form dense canopies, outcompeting native plants³. It receives a High(3) in this category.

Evaluate the dispersal potential of the pest: Score(3)

-Low (1) does not have high reproductive or dispersal potential

-Medium (2) has either high reproductive or dispersal potential

-High (3) has both high reproduction and dispersal potential

4) Economic Impact: Giant hogweed can regrow very rapidly and often invades fallow fields, especially in riparian zones. The plant leaves and stem exude a clear, watery sap that photosensitizes skin, causing a condition known as photodermatitis. Blisters and burns may result on subsequent exposure to the sun. It could effect the skins of small farm animals, especially dogs and Cats². Giant hogweed receives a High(3) in this category.

Evaluate the economic impact of the pest to California using these criteria.

Economic Impact: A, B, D,F

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact: Score (3)

-Low (1) causes 0 or 1 of these impacts

-Medium (2) causes 2 of these impacts

–High (3) causes 3 or more of these impacts

5) Environmental Impact: Giant hogweed can become quite dense, owing to the plant’s prolific seed production and rapid growth rate. Such dense stands crowd out slower growing plants, the thick hogweed canopy displacing native state enlisted endangered plant such as Humboldt milk –vetch (Astragalus agnicidus) that need direct sunlight to grow. The decreased abundance of beneficial native plants can reduce the utility of the area for wildlife habitat. When riparian plants are displaced, stream bank erosion can increase and stream beds can be covered with silt. Giant hogweed receives a High(3) in this category.

Evaluate the environmental impact of the pest on California using the following criteria.

Environmental Impact: A,B,C,D.

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes

B. The pest could directly affect threatened or endangered species

C. The pest could impact threatened or endangered species by disrupting critical habitats

D. The pest could trigger additional official or private treatment programs

E. Significantly impacting cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact: Score(3)

-Low (1) causes none of the above to occur

-Medium (2) causes one of the above to occur

–High (3) causes two or more of the above to occur

Consequences of Introduction to California for Giant hog weed:

Rating (Score): Add up the total score and include it here:

-Low = 5-8 points

-Medium = 9-12 points

-High = 13-15 points

Total points based on above criteria, which does not take into account the pathogen’s already wide distribution in California: High (15).

6) Post Entry Distribution and Survey Information: Giant hogweed has never been found in California and receives a Not Established (0) in this category

–Not established (0) Pest never detected in California, or known only from incursions.

–Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

–Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

–High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: (15)

Uncertainty:

Although this plant is not yet established in California, its invasive behaviour in Washington and Oregon, areas similar to NW California, means that it is high likely to prove invasive in NW CA if it establishes there.

Conclusion and Rating Justification:

Conclusions of the harm associated with this pest to California using all of the evidence presented above: Proposed Rating: Based on the score listed above, Giant hogweed is a High risk. Given its ability to spread widely and displace native plants, an “A” rating is proposed.

References:

Giant Hogweed (Heracleum mantegazzianum). Written Findings of the State Noxious Weed Control Board – Class A Weed. State of Washington. 4 pp. http://idtools.org/id/fnw/factsheet.php?name=14620

Linda Cole; CANIDAE® Pet Foods,San Luis Obispo. Accessed 11-15-2016. http://www.canidae.com/blog/2015/08/pet-owners-beware-of-wild-parsnip-and-giant-hogweed/

Missouri Botanical Garden. Accessed 11-15-2016 http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=275991&isprofile=0&

New York Invasive Species Information, Giant Hogweed. Accessed:11-15-2016 http://www.nyis.info/index.php?action=invasive_detail&id=45

Oregon Department of Agriculture. 2008. Toxic plant alert!: Giant hogweed–Heracleum mantegazzianum. Salem OR: Oregon Department of Agriculture, Plant Division, Noxious Weed Control Program. Accessed: 11-15-2016 http://www.fs.fed.us/database/feis/plants/forb/herman/all.html#40

Ohio State University Extension. Accessed: 11-15-2016 http://ohioline.osu.edu/factsheet/anr-35

USDA Phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD). Accessed: 11-15-2016 https://pcit.aphis.usda.gov/pcit/

Responsible Party:

Javaid Iqbal, California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 403-6695; plant.health[@]cdfa.ca.gov.

Pest Rating : A | Proposed Seed Rating: P

Posted by ls

Weeds

Spanish Heath | Erica lusitanica

January 9, 2017 Javaid Iqbal

California Pest Rating for

Spanish Heath | Erica lusitanica

Family: Ericaceae

Pest Rating: B | Proposed Seed Rating: R

PEST RATING PROFILE

Initiating Event:

Concern about the invasiveness of Spanish heath from the land mangement along the north coast of California.

History & Status:

Background: Erica lusitanica, commonly called Spanish heath is a woody, upright, perennial evergreen shrub growing up to 10 feet tall. It can produce up to 9 million seeds per plant where it is invasive. These seeds are dispersed by wind, water, animal and human transported. It is capable of forming dense stands in forest lands, wild areas, pastureland and on right-of-ways. Leaves are light green, needle like, 3-7 mm long and arranged around the stem in groups (whorls) of three to four. Blooms are a showy mass of small, white to pink, bell (tubular) shaped flowers. Plants begin flowering in December continuing until April. It has shown quick recovery from fire and can be found in disturbed and open sandy areas. It is well adapted to acidic soils and could infest a wide range of shrub and forest habitats^1&3.

Spanish heath is native to southwest Europe and has infested large areas in northern California in Humboldt and Del -Norte counties. It is demonstrating a capacity to infest similar habitat in Oregon and Washington. In parts of Australia and New Zealand, Spanish heath is a major environmental weed that out-competes native vegetation. It impacts the parks, wildland and wildlife refuges result from the aggressive growth and competition demonstrated by this plant⁴.

Official Control: Spanish heath is under official treatment in New Zealand⁵.

California Distribution: Spanish Heath is found along waterways scattered throughout much of Coastal northern CA in Humboldt and Del Norte counties. It is also reported from Mendocino, Santa Cruz and San Francisco counties along the shoreline².

California Interceptions: Two vouchers have been submitted in the CDFA herbarium.

United States: Spanish heath is known from Oregon, and Washington.

Worldwide Distribution: Spanish heath s widely naturalized in the south-eastern parts of Australia, especially in Victoria and Tasmania. It is also reported as naturalized and as an environmental weed in UK and New Zealand⁴.

This risk Spanish Heath would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Spanish heath has established in 4 counties in California and presumably can spread to similar habitats elsewhere in the State. Therefore, there is a high risk that it can establish in California. It receives a High(3) in this category.

Evaluate if the pest would have suitable hosts and climate to establish in California. Score: 3

Low (1) not likely to establish in California; or likely to establish in very limited areas

Medium (2) may be able to establish in a larger but limited part of California

High (3) likely to establish a widespread distribution in California

2) Pest Host Range: Spanish heath does not require any one host, but grow wherever ecological conditions are favorable. It receives a High(3) in this category.

Evaluate the host range of the pest: Score : 3

Low (1) has a very limited host range

Medium (2) has a moderate host range

High (3) has a wide host range

3) Pest Dispersal Potential: Spanish heath has a very high seed production. It can spread by wind, water, animal or human activity. It receives a High(3) in this category.

Evaluate the dispersal potential of the pest: Score: 3

Low (1) does not have high reproductive or dispersal potential

Medium (2) has either high reproductive or dispersal potential

High (3) has both high reproduction and dispersal potential

4) Economic Impact: Spanish Heath only occasionally invades agricultural land. It can lower crop yields, crop value, and change cultural practices. Pasture productivity would suffer as edible forage becomes out-competed by this less desirable shrub. Right-of-way maintenance costs would increase in infested areas³. It receives a High(3) in this category.

Evaluate the economic impact of the pest to California using these criteria:

Economic Impact: A, B,C D

A. The pest could lower crop yield

B. The pest could lower crop value (includes increasing crop production costs)

C. The pest could trigger the loss of markets (includes quarantines by other states or countries)

D. The pest could negatively change normal production cultural practices

E. The pest can vector, or is vectored, by another pestiferous organism

F. The organism is injurious or poisonous to agriculturally important animals

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score (3)

-Low (1) causes 0 or 1 of these impacts

-Medium (2) causes 2 of these impacts

–High (3) causes 3 or more of these impacts

5) Environmental Impact: Spanish heath is well adapted to moist, acidic soils and could infest shrub and forest habitats along the coastal belt in California. It is commonly found growing in close association with Gorse, Scotch, French broom, and Blackberry, especially in riparian and roadside areas³.

Spanish heath can dominate open, disturbed areas, excluding other plants and lowering biodiversity and forms dense patches that could interfere with recreation activities along the coast. Its dense growth leads to competition with native vegetation and could impact sensitive species such as Humboldt milk–vetch (Astragalus agnicidus) and Abruptbeak sedge (Carex abrupta). Spanish heath receives a High (3) in this category.

Evaluate the environmental impact of the pest on California using the following criteria:

Environmental Impact: A,B,C,D,E

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes

B. The pest could directly affect threatened or endangered species

C. The pest could impact threatened or endangered species by disrupting critical habitats

D. The pest could trigger additional official or private treatment programs

E. Significantly impacting cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact: Score (3)

-Low (1) causes none of the above to occur

-Medium (2) causes one of the above to occur

–High (3) causes two or more of the above to occur

Consequences of Introduction to California for Spanish heath:

Rating (Score): Add up the total score and include it here

Low = 5-8 points

Medium = 9-12 points

High = 13-15 points

Total points based on above criteria, which does not take into account the already wide distribution of this invasive plant in California: High (15).

6) Post Entry Distribution and Survey Information: Spanish heath has been found in California and receives a Medium (-2) in this category.

–Not established (0) Pest never detected in California, or known only from incursions.

–Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

–Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

–High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: (13)

Uncertainty:

As this plant is established as an invasive species in western CA, there is little uncertainty associated with this assessment.

Conclusion and Rating Justification:

Conclusions of the harm(s) associated with this pest to California using all of the evidence presented above: Proposed Rating: based on the score listed above the pest is a high risk. This would justify an “A” rating. As the plant is found in five counties in California, the pest would be best assigned a “B” rating.

References:

Brusati, E. (2011). Cal-IPC Inventory update adds eight plants. Cal-IPC News. Accessed 11-18-2016. http://www.cal-ipc.org/ip/management/plant_profiles/Erica_lusitanica.php

Calflora: Information on California plants for education, research and conservation, with data contributed by public and private institutions and individuals, including the Consortium of California Herbaria. Berkeley, California. Accessed 11-18-2016. http://www.calflora.org/cgi-bin/species_query.cgi?where-calrecnum=3070

Oregon Department of Agriculture ! Noxious Weed Control Program. Accessed 11-18-2016. https://www.oregon.gov/ODA/shared/Documents/Publications/Weeds/PlantPestRiskAssessmentSpanishHeath2013.pdf

Weed of Australia, Biosecurity Queenland Edition. Accessed 11-18-2016. http://keyserver.lucidcentral.org/weeds/data/media/Html/erica_lusitanica.htm

USDA-Phytosanitary Certificate Issuance and Tracking System (PCIT) Phytosanitary Export Database ( PExD). Accessed 11-18-2016. https://pcit.aphis.usda.gov/PExD/faces/ReportFormat.jsp

Responsible party:

Javaid Iqbal, California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 403-6695; plant.health[@]cdfa.ca.gov.

Pest Rating: B | Proposed Seed Rating: R

Posted by ls

Weeds

Coco-Yam, Elephant Ear or Taro | Colocasia esculenta

December 8, 2016 Javaid Iqbal

California Pest Rating for

Colocasia esculenta : Coco-Yam, Elephant Ear or Taro

Family: Araceae

Pest Rating: D | Proposed Seed Rating: N/A

PEST RATING PROFILE

Initiating Event:

This plant has been rated as “Q” on the CDFA Plant Pest Rating since 2015.

History & Status:

Background: Colocasia esculenta is a tropical plant grown primarily for its edible corms. It is cultivated as a vegetable most commonly known as taro,Gabi and Abi or Avi. There are dozens of other common names used in other parts of the world including culcas from which the genus name Colocasia is derived; the descriptive anatomical name, elephant ear, eddo, imo, dasheen, coco-yam and malombo. It is believed to be one of the earliest cultivated plants².

Plants have been in cultivation for over 2,800 years as a food crop in equatorial regions including India, China, Southeast Asia, Indonesia, Polynesia, the Mediterranean, Africa, and South America. All parts of the plant are edible if they are thoroughly steamed or boiled to first remove calcium oxalate crystals.The cooked leaves are used in Hawaiian luaus and the corms are mashed into poi¹.

It was grown in Africa and was first brought to the Americas as a food crop for slaves. In 1910, Colocasia esculenta was promoted as an alternative crop to potatoes by the USDA⁵. There are more than 200 cultivars of taro, selected for their edible corms or cormels, or their tropical looking ornamental foliage². It is cultivated commercially on a small scale in the Central valley and Sacramento valley of California⁶.

Official Control: None at this time in California.

California Distribution: Colocasia esculenta is a perennial herb that is not native to California. It has been reported in the Delta in Sacramento, San Joaquin and Solano Counties. It also been found in Southern CA in Orange County³.

California Interceptions: Colocasia esculenta is occasionally sold in nurseries in CA. It is consumed as a vegetable in California and sold state-wide in produce markets.

United States: Colocasia esculenta is wide spread in the southeastern United States⁴. It is a most important source of food in the Hawaiian Islands.

Worldwide Distribution: Colocasia esculenta is an ancient crop grown throughout the tropic and sub-tropics. Because Colocasia esculenta has been in cultivation for so long, no one knows where it truly is native, but all evidence points to Southeast Asia. It is viewed as invasive in FL, HW, PR, Queensland, Cuba, Costa Rica and many of the Pacific Islands.

Consequences of Introduction:

1) Climate/Host Interaction: Risk is Medium (2), as Colocasia esculenta is naturalized in the marshy and watershed areas throughout southeastern America and is spreading there. It is established in one area of the Delta in California.

Evaluate if the pest would have suitable hosts and climate to establish in California:

Score: 2

Low (1) not likely to establish in California; or likely to establish in very limited areas

Medium (2) may be able to establish in a larger but limited part of California

High (3) likely to establish a widespread distribution in California

2) Pest Host Range: Risk is High (3) as weeds do not require any one host, but grow wherever ecological conditions are favorable.

Evaluate the host range of the pest:

Low (1) has a very limited host range

Medium (2) has a moderate host range

High (3) has a wide host range

3) Pest Dispersal Potential: Risk is Medium (2) as the plant spreads vegetatively through rhizomes, stolons, offshoot corms or vegetative fragments.It does not seem to produce seed in CA.

Evaluate the dispersal potential of the pest:

Low (1) does not have high reproductive or dispersal potential

Medium (2) has either high reproductive or dispersal potential

High (3) has both high reproduction and dispersal potential

4) Economic Impact: Risk is Medium (2) as Colocasia produces 2.5′ wide by 3.5′ long leaves with up to 30″ tall patch that could lower the crop yield due to shading and changes in the cultural practices where it is established.

Evaluate the economic impact of the pest to California using these criteria:

Economic Impact: A, D

A. The pest could lower crop yield

B. The pest could lower crop value (includes increasing crop production costs)

C. The pest could trigger the loss of markets (includes quarantines by other states or countries)

D. The pest could negatively change normal production cultural practices

Economic Impact Score: 2

Low (1) causes 0 or 1 of these impacts

Medium (2) causes 2 of these impacts

High (3) causes 3 or more of these impacts

5) Environmental Impact: Risk is High (3) as it invades wetland edges, swamps, blackwater streams, lakes and disrupt natural wetland communities of California. It is established in a state park where it forms a dense thicket at the wetland interface; this will encourage treatment for control. If it spreads, it could affect populations of sensitive species such as Mason’s lilaeopsis (Lilaeopsis masonii), CA Clapper rail (Rallus obsoletus), Suisun aster (Symphyotrichum lentum) and Delta tula pea (Lathyrus jepsonii).

Evaluate the environmental impact of the pest on California using the following criteria:

Economic Impact: A, C, D

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes

B. The pest could directly affect threatened or endangered species

C. The pest could impact threatened or endangered species by disrupting critical habitats

D. The pest could trigger additional official or private treatment programs

E. Significantly impacting cultural practices, home/urban gardening or ornamental plantings.

Score the pest for Environmental Impact:

Low (1) causes none of the above to occur

Medium (2) causes one of the above to occur

High (3) causes two or more of the above to occur

Consequences of Introduction to California for Colocasia esculenta :

Rating (Score): Add up the total score and include it here:

Low = 5-8 points

Medium = 9-12 points

High = 13-15 points

Total points based on above criteria, which does not take into account the pathogen’s already wide distribution in California: Medium (12).

Score: Low (–1)

-Not established (0) Pest never detected in California, or known only from incursions.

-Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

-Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: (11)

Uncertainty:

This plant has been known in Southeastern America for over 100 years and spreading colonies have been detected.So, there is low uncertainty that it will continue to spread in wetlands of California.

Conclusion and Rating Justification:

Proposed Rating: based on the score listed above, the pest is Medium risk for further invasions of California. It has a potential to invade the wet areas of California, and it is already reported in 4 counties. Nevertheless, as Colocasia esculenta is an agricultural commodity in California, a “D” rating is justified.

References:

1. Avent Tony and Carey Dennis, (2016). Cool Colocasias; Plant Delights Nursery, Inc. Accessed 11-15-2016.

http://www.plantdelights.com/Article/Colocasia-Elephant-Ears

Colocasia esculenta, Encyclopedia of Life.Eol community website .

http://www.eol.org/pages/1091931/overview

Calflora: Information on California plants for education, research and conservation, with data contributed by public and private institutions and individuals, including the Consortium of California Herbaria. 2016. Berkeley, California. Accessed 11-15-2016.

http://www.calflora.org/cgi-bin/species_query.cgi?where-calrecnum=13042

Federal database with information on identification and distribution, and links to websites in individual states. Accessed 11-15-2016.

http://plants.usda.gov/core/profile?symbol=COES

Swearingen, J., C. Bargeron. 2016 Invasive Plant Atlas of the United States. University of Georgia Center for Invasive Species and Ecosystem Health

http://www.invasiveplantatlas.org/subject.html?sub=5369

Taro root (colocasia esculenta) reported Naturalizing in ca;ifornia by CA State Parks.

http://www.cal-ipc.org/symposia/archive/pdf/2014/Poster2014_Robison.pdf

Responsible Party:

Javaid Iqbal, California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 403-6695; plant.health[@]cdfa.ca.gov.

Comment Format:

♦ Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

Example Comment:

Consequences of Introduction: 1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

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Pest Rating: D | Proposed Seed Rating: N/A

Posted by ls

Weeds

Arctotheca calendula (L.) Levyns (Capeweed)

December 8, 2016 Raj Randhawa

California Plant Pest Rating

Arctotheca calendula (L.) Levyns (Capeweed)

Asterales; Asteraceae

Pest Rating: A | Proposed Seed Rating: P

PEST RATING PROFILE

Initiating Event:

This plant was listed as a noxious weed in California in 2010 (Invasive species compendium- CABI).

History & Status:

Capeweed is a Rosette-forming winter annual, up to 30 cm tall. It has typical daisy flowers heads with dark purple disk flowers and yellow ray flowers. Plants typically colonize open sites with exposed soils. Capeweed is introduced from South Africa, but it is also common in Australia, where it is an abundant pasture weed. Certain capeweed populations in Australia have developed resistance to bipyridylium herbicides. Handling plants can cause contact dermatitis in sensitive individuals. Capeweed has proven invasive in horse pastures and vineyards where taller, more palatable vegetation is removed. There has been much confusion between capeweed and prostrate capeweed (A. prostrata). Prostrate capeweed is a common groundcover perennial sold in flats in nurseries in mild areas of California. Prostrate capeweed can be locally invasive where it has been planted, as it actively spreads to form patches vegetatively. However, it does not form seeds in California; perhaps there is only one self-incompatible clone in cultivation at this time.

Official Control: Capeweed has been recognized as a harmful organism in Brazil, Colombia and Peru. It has naturalized in Australia, New Zealand and other countries in Asia, Africa, South America and Europe.

California Distribution: Capeweed may have arrived in California in a shipment of grass seed from Australia, where it is a common weed. Because of taxonomic confusion with prostrate capeweed, the range of capeweed is somewhat ambiguous. It has been reported in Alameda*, Amador, Humboldt*, Los Angeles, Mendocino, Monterey*, Marin*, Merced*, Sacramento, Santa Barbara, Santa Cruz*, San Francisco, San Luis Obispo, San Mateo*, Sonoma, Stanislaus* and Yolo Counties (Cal Flora Databse: Distribution by county: Arctotheca calendula (L.) Levyns Cape weed). Asterixed county reports are supported by confirmed, identified vouchers.

California Interceptions: 11 vouchers have been submitted to CDFA for identification between 2000 and 2015 (Pest and Damage Report Database).

International: Capeweed is native to South Africa. It is reported as naturalized in central Portugal and southwestern Spain, southern Portugal, New Zealand and as an environmental weed in Australia. (Lazarides and Hince, 1993 ). Capeweed has been raised as an ornamental in England since the mid-18^th century (USDA APHIS Pest Risk Assessment).

Habitat: Capeweed prefers sandy, well drained soil, sand dunes,steam banks and rocky outcrops. It is used as a groundcover (Joffe, 2001). It does not thrive on soils low in potassium and high in salt. Areas on light textured soils devoid of vegetation during late summer /autumn are most likely to become infested with capeweed (Department of Primary Industries, Water and Environment , Tasmania, 2002). As it is avoided by livestock, it can spread quickly in horse pastures.

This risk capeweed would pose to California is evaluated below:

Consequences of Introduction:

1) Climate/Host Interaction: Risk is High (3), as this plant is naturalized along the coast of California and at five inland sites in the San Joaquin/Sacramento region. (Cal Flora Databse: Distribution by county: Arctotheca calendula (L.) Levyns: Cape weed).

Evaluate if the pest would have suitable hosts and climate to establish in California:

Score: 3

Low (1) not likely to establish in California; or likely to establish in very limited areas

Medium (2) may be able to establish in a larger but limited part of California

High (3) likely to establish a widespread distribution in California

2) Pest Host Range: Risk is High (3) as weeds do not require any one host, but grow wherever ecological conditions are favorable.

Evaluate the host range of the pest:

Score: 3

– Low (1) has a very limited host range

– Medium (2) has a moderate host range

– High (3) has a wide host range

3) Pest Dispersal Potential: Risk is High (3). Capeweed has both high reproduction potential and highly mobile propagules. The plant reproduces via seeds. One plant can spawn a population spreading to cover up to 200 square feet in one to two years (Mathias, 1982; CDFA , 2002). Capeweed stem pieces with nodes can spread to new location by heavy equipment (Bossard, et al. 2002). Dispersal can be aided by wind or in contaminated soil. (Miles, 2002) Human activity and animals also aid in spread of seeds and rooted stolons (Wood 1994).

Evaluate the dispersal potential of the pest:

Score: 3

Low (1) does not have high reproductive or dispersal potential

Medium (2) has either high reproductive or dispersal potential

High (3) has both high reproduction and dispersal potential

4) Economic Impact: Risk is High (3) as capeweed can become a troublesome weed in pastures, crops and home gardens in California. It can smother grasses and clover seedlings in newly sown pastures in the state. Capeweed can dominate overgrazed pastures in drier regions of California and can die off during summer, leaving bare areas vulnerable to invasion by other weeds.

It invades disturbed soil along roadsides and in crops. Capeweed can cause poisoning in livestock, if they consume it. Seeds can become embedded in wool. This can result in reduced yields. It reduces the value of stock by lowering their weight. Capeweed does not provide continous ground cover and feed value over summers (APHIS Weed Risk Assesment).

Evaluate the economic impact of the pest to California using these criteria:

Economic Impact: A, B, F

A. The pest could lower crop yield

B. The pest could lower crop value (includes increasing crop production costs)

C. The pest could trigger the loss of markets (includes quarantines by other states or countries)

D. The pest could negatively change normal production cultural practices

E. The pest can vector, or is vectored by another pestiferous organism

F. The organism is injurious or poisonous to agriculturally important animals

G. The organism can interfere with the delivery or supply of water for agricultural use

Economic Impact Score: 3

Low (1) causes 0 or 1 of these impacts

Medium (2) causes 2 of these impacts

High (3) causes 3 or more of these impacts

5) Environmental Impact: Risk is High (3) in California. Capeweed disrupts natural grassland communities that are grazed, invades native habitat along the coast including coastal prairie, and triggers additional treatment to control it. In desert areas of California, Capeweed can increase the risk of soil erosion as its mature plants dry up and break quickly, leaving no cover over summer. It can also threaten native plant communities in Califorinia by crowding out grasses, herbs and small herbs (Bossard et al., 2000). Capeweed can cause hay fever and handling plants can cause contact dermatitis in sensitive people (CDFA 2002). It can escape into lawns and adjacent planting areas in California (Perry, 1992). Since there are no registered biological agents for Capeweed control, additional private or official treatments may be needed for its control ( CDFA 2002).

Evaluate the environmental impact of the pest on California using the following criteria:

Environmental Impact: A, C, D

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes

B. The pest could directly affect threatened or endangered species

C. The pest could impact threatened or endangered species by disrupting critical habitats

D. The pest could trigger additional official or private treatment programs

E. Significantly impacting cultural practices, home/urban gardening or ornamental plantings.

Score the pest for Environmental Impact:

Environmental Impact Score: 3

Low (1) causes none of the above to occur

Medium (2) causes one of the above to occur

High (3) causes two or more of the above to occur

Consequences of Introduction to California for capeweed:

Add up the total score and include it here:

Low = 5-8 points

Medium = 9-12 points

High = 13-15 points

Total points based on above criteria: High (15).

6) Post Entry Distribution and Survey Information:
Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included:

Score: Medium (–2)

-Not established (0) Pest never detected in California, or known only from incursions.

-Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

–Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: (13).

Uncertainty:

Capeweed has naturalized in coastal and some inland areas of Northern California. There is confusion as to whether reports refer to capeweed or prostrate capeweed. Nevertheless, it has the potential to get widely established in desert areas and grazed pastures. There is little uncertainty as to whether this plant can establish widely in CA, as it has establsihed in CA and has spread widely in silmilar habitats in Australia.

Conclusion and Rating Justification:

Proposed Rating: based on the score listed above the pest is a high risk. Because it has spread in certain areas of northern california and has a good potential to widely spread in the state, an A rating would be justifed. Because it can spread in grass seed, it should be prohibited from seed for planting.

References:

Baldwin, B. G., D. H. Goldman, D. J. Keil, R. Patterson, T. J. Rosatti, and D. H. Wilken, editors. 2012. The Jepson manual: vascular plants of California, second edition. University of California Press, Berkeley.

Bossard, C.C., J.M. Randall, and M.C. Hoshovsky. 2000. Invasive Plants of California Wildlands. pp.49-53. University of California Press.

California Department of Food and Agriculture (CDFA) Encycloweedia Homepage. 2002. Notes on Identification, Biology, and Management of Plants defined as Noxious Weeds by California Law. http://pi.cdfa.ca.gov/weedinfo/.

Cal Flora Databse: Distribution by county: Arctotheca calendula (L.) Levyns

Capeweed https://www.calflora.org/cgi-bin/county_taxon.cgi?where-calrecnum=634

Consortium of California Herbaria (ucjeps.berkeley.edu/consortium/). 2014.

Department of Primary Industries, Water and Environment, Tasmania website:

www.dpiwe.tas.gov.au. Weed Service Sheet 128 – Arctotheca calendula. 2002.

Environmental weeds of Australia for Biosecurity Queensland : Arctotheca Calendula– Factsheet http://keyserver.lucidcentral.org/weeds/data/media/Html/arctotheca_calendula.htm

Fairnie, I.J. Nitrite poisoning in sheep due to capeweed (Arctotheca calandula). Australian Veterinary Journal 1969, February; 45(2): 78-9.

Invasive species compendium: Arctotheca calendula (Capeweed): Accessed 11/9/2016 http://www.cabi.org/isc/datasheet/6729#20097200136

Lazarides, M. and B. Hince, editors. 1993. CSIRO handbook of economic plants of Australia. P. 24. CSIRO, Victoria, Australia

Lehtonen, Polly, USDA-APHIS PPQ Biological and Technical Services: Weed Risk Assesment for Arctotheca calendula (L.) Levyns; Accessed 11/9/2016 https://www.aphis.usda.gov/plant_health/plant_pest_info/weeds/downloads/wra/ArctothecacalendulaWRA.pdf

Mahoney, A. M. & R. J. McKenzie. 2008. Notes On Two Southern African Arctotis Species (Arctotideae: Asteraceae) Growing In California. Madroño 55: 244–247.

Mathias, M. E., editor. 1982. Flowering Plants in the Landscape. University of California Press. p. 139

Miles, J. 2002. Capeweed (Arctotheca calendula) weed fact sheet, Eurobodalla Shire Council, New South Wales, Australia, South Coast Weeds website. Accessed 11/9/2016 http://www.esc.nsw.gov.au

Perry, B. 1992. Landscape Plants for Western Regions, an illustrated guide to plants for water conservation. Claremont CA: Land Design Pub. pp. 94, 125-126.

Pest and Damage Record Database; Plant Health and Pest Prevention Services, California Department of Food and Agriculture. Accessed on 11/9/2016

Pethick D.W., Chapman, H.M. The effect of Arctotheca calendula (capeweed) on digestive function of sheep. Australian Veterinary Journal 1991 Nov.; 68(11): 361-3

Weed Identification in Australia: Capeweed http://www.weeds.org.au/cgi-bin/weedident.cgi?tpl=plant.tpl&state=&s=&ibra=all&card=H70

Wood, H. 1994. The introduction and spread of Capeweed, Arctotheca calendula (L.)Levyns (Asteraceae) in Australia. Plant Protection Quarterly 9, 2-8.

Responsible Party:

Raj Randhawa, Senior Environmental Scientist; Dean G. Kelch, Primary Botanist; California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 654-0312; plant.health[@]cdfa.ca.gov.

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Pest Rating: A | Proposed Seed Rating: P

Posted by ls

Weeds

False Yellowhead | Dittrichia viscosa (L.) Greuter

December 1, 2016 Dean Kelch

California Pest Rating for

False Yellowhead | Dittrichia viscosa (L.) Greuter

Asteridae: Asteraceae

Pest Rating: A | Proposed Seed Rating: P

PEST RATING PROFILE

Initiating Event:

False yellowhead (Dittrichia viscosa) has been rated as “Q” on the CDFA Plant Pest Rating since 2014. This plant is on the “Alert list” for Environmental weeds in Australia. Recent reports of its presence in Solano County has prompted issuance of a permanent rating.

History & Status:

False yellowhead (Dittrichia viscosa) is an erect, perennial, soft-wooded shrub, 1–1.5 m tall and 1 m wide. Its leaves are greyish-green, partially clasping and elliptical. The yellow flowers are daisy-like and 10–20 mm across, with radiating petal-like flowers. The flowers are surrounded by narrow, triangular, sticky bracts. The seeds are approximately 2 mm long, with about 15–25 bristles at the base (Ratcliffe, 1976). The roots can be quite substantial, even in small plants. The young stems and leaves are covered with glandular hairs which exude a sticky foul-smelling oil. The oil can cause allergic reactions. It is native to Northern Africa, the Middle East, India, and southern Europe (Brullo & de Marco, 2000), but it has expanded its range in response to human disturbance and proved tolerant of harsh water and mineral stress (Wacquant, 1990; Thompson, 2005; Murciego et al. 2007). False yellowhead inhabits disturbed places, roadsides, pastures, fields, riparian woodlands, levees, washes, and margins of tidal marshes. (Blanco 2011; Wacquant, 1990). False yellowhead was first found in California in 2014 (Consortium of California Herbaria). False yellowhead’s ecology seems to be similar to its close relative stinkwort (D. graveolens), a serious weed in California (Ditomaso & Brownsey, 2013; Wacquant, 1990).

Official Control: False yellowhead has not been listed as a harmful organism (Phytosanitary export database- USDA Phytosanitary Certificate issuance and Tracking system (PExD). The Solano County Agricultural Commissioner’s staff has been controlling and monitoring this plant since it was first found.

California Distribution: Known only from Solano County in California (Consortium of California Herbaria).

California Interceptions: It has been found growing along McGary Road in Solano County, as reported multiple times by the county agricultural commissioner’s office. (Pest and Damage Report Database). It has not yet been intercepted at CA borders.

United States: False yellowhead was collected in three states in the eastern U.S. (USDA Plants), but it is unlikely that it persisted beyond the late1800s. (FNA, 1993+).

International: False yellowhead is common throughout the Mediterranean. Its native range includes the coasts of southern Europe (including France, Spain, Greece, Italy, Bulgaria and Turkey), the Middle East (Israel, Jordan and Syria), as well as northern Africa (Algeria, Egypt and Libya) (Ratcliffe, 1976; Brullo & de Marco, 2000). It is spreading rapidly in Southeastern and Southwestern Australia (Baldwin et al., 2012).

The risk False yellowhead would pose to California is evaluated below:

Consequences of Introduction:

1) Climate/Host Interaction: False yellowhead is a ruderal plant species adapted to areas disturbed and altered by human activity (Wacquant, 1990). The typical habitats of viscosa include arroyos, abandoned agricultural fields, roadsides, trails, and disturbed urban sites (Ratcliffe, 1976). It occurs on various soil types and is tolerant of high mineral soils (Wacquant, 1990). Although it is drought tolerant, it prefers the margins of wetlands (Warlop et al., 2010). Once established after disturbance, it can spread to less disturbed situations (Wurcquart, 1990). Therefore, false yellowhead receives a High (3) in this category.

Evaluate if the pest would have suitable hosts and climate to establish in California:

Score: 3

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Host Range: Risk is High (3) as weeds do not require any one host, but grow wherever ecological conditions are favorable.

Evaluate the host range of the pest:

Score: 3

– Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: False yellowhead spreads via seed. Seed dispersal is aided by an arrangement of bristles at the end of the seed (pappus) that catches the wind. (Australian Weed Management Guide). It produces prolific seed that secretes a sticky exudate causing seed to cling to clothing, animal fur and machinery. The seed bank of its close relative Stinkwort is moderately persistent (Cal-IPC). False yellowhead receives a High (3) in this category.

Evaluate the natural and artificial dispersal potential of the pest:

Score: 3

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

– High (3) has both high reproduction and dispersal potential.

4) Economic Impact: False yellowhead can lower range productivity. It is unpalatable to livestock (Philbey and Morton, 2000). Furthermore, because of the barbs on the pappus of the seeds, it leads to enteritis and other gastrointestinal disease in livestock. As they are similar to those of Stinkwort, false yellow head is likely to have similar impacts on livestock. It is thought that false yellowhead would have similar impacts on grazing animals. Thirty years after introduction to South Australia, false yellowhead is a bad weeds of roadsides. Some people are allergic and develop severe dermatitis after contacting false yellowhead plants (Máñez et al., 1999; Hernández et al., 2001). It is also allelopathic to other plants and suppresses seed germination (Omezzine et al., 2011). False yellowhead receives a Medium (2) in this category.

Evaluate the economic impact of the pest to California using the criteria below:

Economic Impact: D, F

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 2

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact: False yellowhead is likely to trigger new chemical treatments by ranchers and land managers. The plant can dominate roadsides, disturbed grassland, and wetland margins, excluding native plants and lowering biodiversity (Australia Weed Management Guide). Rare taxa that might be affected in CA include grassland species such as showy Indian clover (Trifolium amoenum) and CA filaree (California macrophylla), and vernal pool species such as Burke’s goldfields (Lasthenia burkei) and CA tiger salamander (Ambystoma californiense). The plant can disrupt natural communities and exclude cultural plants from a landscape. False yellowhead receives a High (3) in this category.

Evaluate the environmental impact of the pest on California using the criteria below:

Environmental Impact: A, C, D

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Score the pest for Environmental Impact:

Environmental Impact Score: 3

– Low (1) causes none of the above to occur.

– Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for False yellowhead: High (14)

Add up the total score and include it here:

–Low = 5-8 points

–Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: False yellowhead has been found in one county in California. It receives a Low (-1) in this category.

Score: -1

–Not established (0) Pest never detected in California, or known only from incursions.

-Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

–Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

–High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: High (13)

Uncertainty:

Uncertainty is low, as the plant has spread widely in the Mediterranean and South Australia. It also shows signs of fast establishment in its one known occurrence in California.

Conclusion and Rating Justification:

An A rating is recommended, as the plant is invasive, but not yet widespread. There is still the chance to eradicate this plant from North America.

References:

Australian Weed Management Guide. False yellowhead. Accessed 10/11/2016:

https://www.environment.gov.au/biodiversity/invasive/weeds/publications/guidelines/alert/pubs/d-viscosa.pdf

Baldwin, B. G., D. H. Goldman, D. J. Keil, R. Patterson, T. J. Rosatti, and D. H. Wilken, editors. 2012. The Jepson manual: vascular plants of California, second edition. University of California Press, Berkeley.

Blanco G. 2011. Dittrichia in Claves de la Flora Vascular de Andalucía Oriental. G. Blanca, B. Cabezudo, M. Cueto, C. Morales Torres & C. Salazar, eds. Servicio de Publicaciones de las Universidades de Almería, Granada, Jaén y Málaga. Universidad de Granada. Granada, Spain.

Brullo, S & de Marco, G. 2000. Taxonomical revision of the genus Dittrichia (Asteraceae), Portugaliae Acta Biol. 19: 341–354.

Consortium of California Herbaria. Accessed 10/11/2016: ucjeps.berkeley.edu/consortium/

Flora of North America Editorial Committee, eds (FNA). 1993+. Flora of North America North of Mexico. 16+ vols. New York and Oxford.

Hernández, V., R. M. del Carmen, S. Máñez, J. M. Prieto, R. M. Giner, & J. L. Ríos. 2001. A mechanistic approach to the in vivo anti-inflammatory activity of sesquiterpenoid compounds isolated from Inula viscosa. Planta Medica 67: 726-731.Máñez, S., M. C. Recio, I. Gil, C. Gómez, R. M. Giner, P. G. Waterman & J. L. Ríos 1999. A glycosyl analogue of diacylglycerol and other antiinflammatory constituents from Inula viscosa. Journal of Natural Products 62: 601-604.

Murciego, A. M., A. G. Sánchez, M. A. R. González, E. P. Gil, C. T. Gordillo, J. C. Fernández & T. B. Triguero 2007. Antimony distribution and mobility in topsoils and plants (Cytisus striatus, Cistus ladanifer and Dittrichia viscosa) from polluted Sb-mining areas in Extremadura (Spain). Environmental Pollution 145: 15-21.

Omezzine, F., A. Rinez, A. Ladhari, M. Farooq & R. Haouala. 2011. Allelopathic potential of Inula viscosa against crops and weeds. International Journal of Agriculture and Biology 13: 841-849.

Parolin P, M Ion Scotta, & C Bresch. 2014. Biología de Dittrichia viscosa, una planta ruderal del Mediterráneo. Phyton (Buenos Aires) vol.83.

Philbey A. & A.G. Morton 2000. Pyrogranulomatous enteritis in sheep due to penetrating seed head of Dittrichia graveolens. Australian Veterinary Journal 78: 858-860

Pest and Damage Record Database, Plant Health and Pest Prevention Services, CA Department of Food and Agriculture. Assessed Date: 10/18/2016

Phytosanitary Export Database- USDA Phytosanitary Certificate issuance and Tracking system (PExD), Date Assessed: 10/18/2016. https://pcit.aphis.usda.gov/PExD/faces/PExDReport.jsp

Ratcliffe, D. 1976. Dittrichia in Flora Europaea Vol. 4: Plantaginaceae to Compositae. T. G. Tutin, V. H. Heywood, N. A. Burges, D. H. Valentine, S. M. Walters, & D. A. Webb, eds. Cambridge University Press. United Kingdom.

Sinden J., R. Jones, S. Hester, D. Odom, C. Kalisch & R. James (2004). The economic impact of weeds in Australia. Report to the CRC for Australian Weed Management. Pp. 1-65.

Thompson, J. D. 2005. Plant Evolution in the Mediterranean. Oxford University Press, Oxford.

USDA Plants; Dittrichia viscosa. Accessed 10/11/2016: http://plants.usda.gov/core/profile?symbol=DIVI6

Wacquant, J. P. 1990. Biogeographical and physiological aspects of the invasion by Dittrichia (ex-Inula) viscosa W. Greuter, a ruderal species in the Mediterranean Basin. Pp. 353-364 in Biological Invasions in Europe and the Mediterranean Basin. F. di Castri, A.J. Hansen, and M. Debussche, eds. Springer Netherlands, Dordrecht.

Responsible Party:

Dean G. Kelch, Primary Botanist; California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 403-6650; plant.health[@]cdfa.ca.gov

Pest Rating: A | Proposed Seed Rating: P

Posted by ls

Weeds

Old Man’s Beard | Clematis Vitalba

November 23, 2016 Raj Randhawa

California Pest Rating for

Clematis vitalba: Old man’s beard

Ranunculales: Ranunculaceae

Pest Rating: A | Proposed Seed Rating: P

PEST RATING PROFILE

Initiating Event:

Old Man’s beard (Clematis vitalba) is listed as a B rated quarantine weed in Oregon and Class C noxious weed in Washington. In 2014, this species was added as new alert weed in California (Joe DiTomaso, UC Davis) and was listed on California Invasive Species Council’s watch list in December, 2015. It has been reported several times growing in Marin, Santa Cruz and San Francisco Counties recently. (Cal Flora: Distribution by County: Clematis vitalba). Due to this, a risk assessment of this known weed is critical to designate an official rating.

History & Status:

Old man’s beard is a broad leaved, deciduous, woody climbing vine that lives up to 40 years (West, 1991). It grows to 65 feet long and acts as a ground cover in the absence of trees to climb. New shoots can grow 6 feet per year and older plants can grow 30 feet per year. (Kings county Noxious Weed Control Program). Old Man’s Beard is native to Europe, Africa and south west Asia. It has been introduced to and naturalized in North America, Australia and New Zealand. This plant is found on disturbed lands, forest edges and wooded areas with partial sun. It is also capable of growing on hedgerows, fence lines, dunes, riverbanks and grassland. Old man’s beard can easily invade riparian vegetation, waste land, tall grasses and disturbed urban areas. Since this plant grows on road sides, the seeds can be transported on vehicles from known infestations to new sites. The highest risk of introduction is through the intentional introduction of this plant as an ornamental, plants and seeds sold by nurseries, mail order and online sales (Invasive Species Compendium: CABI Database: Clematis vitalba). It is self-pollinated and can also be pollinated by wind or insects. Old man’s beard produces up to 100,000 seeds per plant per year. Seeds can remain viable for up to five years in the soil (Kings county noxious weed control program).

Official Control: Old man’s beard is recognized as a harmful organism in New Zealand and is listed as invasive weed in the United Kingdom and Canada. In the United States, it is recognized as invasive in Oregon, Washington and Maine (Invasive species compendium: CABI Database: Clematis vitalba). It is not yet fully established in California.

California Distribution: Old man’s beard has been observed in limited areas of Marin, Santa Cruz and Santa Clara counties (Consortium of California Herbaria).

California Interceptions: Old man’s beard has not been intercepted in California through regulatory pathways (Pest and Damage Report Database, CA Department of Food and Agriculture), but has been reported to CDFA from National and State Park personnel.

United States: Old man’s beard has a long history in North American Horticulture. It was first introduced into the US between 1830 and 1840 (ACS, 2003). Currently, it has a limited naturalized distribution in the states of Oregon, Maine, Washington and California (Invasive species compendium: CABI Database: Clematis vitalba).

International: Old man’s beard is native to Europe and is reported as naturalized in Ireland, Poland, Sweden, Norway and other areas bordering its native range. It is also naturalized in parts of North America, Australia and New Zealand. (Invasive species compendium: CABI Database: Clematis vitalba)

The risk Old man’s beard would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Old man’s beard is a warm temperate species. It grows on well-drained, moderately fertile and moist soils. In gardens, it responds well to the application of lime, but it is not restricted to calcareous sites in the wild. It is generally found in areas where annual rain fall is greater than 800 mm. California coastal areas with moist soils and heavy precipitation during the winter months can be at a risk for this invasive plant to establish. Risk is Medium (2).

Evaluate if the pest would have suitable hosts and climate to establish in California. Score: 2

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Host Range: Old man’s beard is capable of growing in variety of habitats and on a number of substrates including trees and shrubs on forest margins, riverbanks, fence lines, dunes, hedgerows, grasslands and even in urban areas. (Invasive species compendium: CABI Database: Clematis vitalba). It has been observed recently near creeks, slopes and forest areas along California coast. Risk is High (3).

Evaluate the host range of the pest. Score: 3

– Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Old man’s beard is pollinated by wind and insects. It can produce up to 100,000 seeds per plant and seeds can remain viable up to five years. (Kings County Noxious Weed Control Program). Seeds can be spread by wind, water, humans and animals. It can also spread by fragmentation when roots are produced from both separated and attached stem fragments. This weed can be accidentally spread along road sides by turbulence created by moving motor vehicles. Additionally, it has been introduced intentionally as an ornamental plant (Invasive species compendium: CABI database: Clematis vitalba). Risk is High (3).

Evaluate the natural and artificial dispersal potential of the pest. Score: 3

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

– High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Old man’s beard is a host of Alfalfa mosaic virus (Polak, 1986). There may be an increased risk of disease transmission by Clematis vitalba near vineyards. It has been regarded as a minor weed in European vineyards as well as a weed of pine plantations (Mitchell, 1975). Old man’s beard is poisonous to grazing livestock animals (West, 1991). Risk is High (3).

Evaluate the economic impact of the pest to California using the criteria below.

Economic Impact: A, B, E, F

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 3

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact: Infestation with Old man’s beard reduces biodiversity by blocking the light and out-competing native plants and trees. This could cause extirpation of local species that have restricted distributions. Its vines can form a dense, light absorbing canopy that suppresses all vegetation it climbs. Its vigorous growth and heavy weight can break the trees beneath it, leaving previously heathy forest a low, long-lived thicket of vines. (Global Invasive Species Database). Damage from old man’s beard can enhance invasion of native habitats by other invasive plants. As it occurs on public land, its presence will lead to treatment programs. Risk is High (3).

Evaluate the environmental impact of the pest on California using the criteria below.

Environmental Impact: A, C, D

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest could significantly impact cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact Score: 3

– Low (1) causes none of the above to occur.

– Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Old man’s beard: High (14)

Add up the total score and include it here.

-Low = 5-8 points

-Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Old man’s beard has a limited distribution in Marin County and has been observed sparsely in Santa Cruz and San Francisco counties (Consortium of California Harbaria). Score: -1

-Not established (0) Pest never detected in California, or known only from incursions.

-Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

-Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: High (13)

Uncertainty:

Old man’s beard may not spread and get established in drier areas of California but has it has a strong ability to grow and spread in the coastal areas with ample moisture and higher than average precipitation. It has not yet spread to vineyards and pine plantations in California, but has done so in Europe.

Conclusion and Rating Justification:

Old man’s beard has been recognized as a threat in Oregon and Washington. The fact that it has been observed multiple times, growing in the areas of Marin and Santa Cruz counties indicates that it can spread and get established in coastal areas of the California. An “A” rating is proposed at this time for this invasive weed, as it can still be eradicated from California.

References:

Plants Profile of Clematis vitalba (evergreen clematis), Accessed:10/06/2016 http://plants.usda.gov/core/profile?symbol=CLVI6

West CJ, 1991. Literature review of the biology of Clematis vitalba (old man’s beard). DSIR Land Resources Vegetation Report No. 725. Library@landcareresearch.co.nz.

Invasive Species Compendium- Clematis Vitalba, Accessed:10/06/2016 http://www.cabi.org/isc/datasheet/14280

Kings county Noxious Weed Control Program: Best Management Practices- Old Man’s Beard http://your.kingcounty.gov/dnrp/library/water-and-land/weeds/BMPs/Old-mans-beard-Clematis-vitalba-control.pdf

Plants for a Future: Clematis vitalba; Accessed: 10/06/2016 http://www.pfaf.org/user/Plant.aspx?LatinName=Clematis+vitalba

Cal Flora: Clematis vitalba; Accessed: 10/06/2016 http://www.calflora.org/cgi-bin/county_taxon.cgi?where-calrecnum=8710

Consortium of California Harbaria: Accessed 10/20/2016 http://ucjeps.berkeley.edu/consortium/

California Agriculture; University of California Agricultural and Natural Resources http://calag.ucanr.edu/Archive/?article=ca.v068n03p89

Global Invasive species database http://www.iucngisd.org/gisd/species.php?sc=157

Mitchell AF, 1975. Three forest climbers, Ivy, old man’s beard, and honeysuckle. Forestry Commission Forestry Record, HM Stationery Office, 1-12

Polak Z, 1996. Spontaneous hosts of alfalfa mosaic virus ascertained in ruderal plant associations in central Bohemia. Ochrana Rostlin, 32:161-165

Pest and Damage Records Database: Plant Health and Pest Prevention Services, California Department of Food and Agriculture, Assessed: 10/19/2016

Distribution of Climatis vitalba: Discover Life: Global Mapper- Global Biodiversity Information Facility. http://www.discoverlife.org/mp/20m?kind=Clematis+vitalba