Category Archives: Weeds

Plants (weeds)

Weeds

Balloon Plant | Asclepias physocarpa

November 3, 2017 Dean Kelch

California Pest Rating

Balloon Plant | Asclepias physocarpa

Family: Apocynaceae

Pest Rating: C | Proposed Seed Rating: None

PEST RATING PROFILE

Initiating Event:

Asclepias physocarpa is currently Q-rated and was recently intercepted at the Benton Border Station (PDR BE0P06666758). A pest rating proposal is required to support an official pest rating.

History & Status:

Background: Asclepias physocarpa, commonly called balloon plant, is native to southeast Africa. It is an upright, shrubby perennial that typically grows 4-6′ tall and has lanceolate green leaves. This milkweed family member is perhaps best noted for its soft, spherical (balloon-like), lime-green seed pods, which are 5-7.5 cm long and covered with soft spines 7-10 mm long⁷. Pods change in color to tan before splitting open in the fall to release large numbers of small, black seeds, which measure approximately 4.5 mm long by 2 mm wide and are topped with a tuft of silky-white hairs approximately 3 cm long. These seeds are wind-dispersed^{1, 3}.

Asclepias physocarpa is a food plant for the larvae of the monarch butterflies (Danaus spp.). The caterpillars are immune to the poisonous alkaloids in Asclepias physocarpa and have developed the ability to store them and pass them on to the pupa and adult butterfly, that are then unpalatable and/or poisonous to predators⁵.

Asclepias physocarpa is sometimes placed in the segregate genus Gomphocarpus, but recent evidence support retaining it in the large genus Asclepias (milkweeds)².

Worldwide Distribution: Asclepias physocarpa is native to South Africa, Swaziland, and Mozambique. It was introduced to various Mediterranean countries, China, India, Mexico, Central America, tropical South America, and Western Australia¹.

Official Control: Asclepias physocarpa is not considered to be a noxious weed by any state government authorities⁶. However, it is listed as an invasive weed in Hawaii, French Polynesia, the Canary Islands, New Caledonia, China, Australia, Cuba, Jamaica, India, and Italy¹.

California Interceptions: One recent interception record (PDR BE0P06666758) was reported in the Pest and Damage Record Database by CDFA⁴. A few voucher specimens have been collected from gardens and in disturbed areas near new developments in southern CA.

The risk Asclepias physocarpa (Balloon Plant) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Asclepias physocarpa can grow in waste places, disturbed sites, and roadsides. It may able to establish in a larger but limited part of California. Therefore, it receives a Medium (2) 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: Asclepias physocarpa does 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: Asclepias physocarpa spreads by seeds and each seed has a tuft of silky hairs that facilitates dispersal by wind and water. They may also be dispersed as a contaminant of crops, fodder, soil, or in mud attached to animals or machinery¹. Each plant produces several hundred seeds per year. It receives a Medium (2) in this category.

Evaluate the host range 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: Asclepias physocarpa has been cultivated in California for decades, but apparently has rarely escaped gardens. It exudes a milky white latex that is poisonous to livestock and humans, so an infestation could reduce the productivity of pastures¹. It receives a High (3) 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: Asclepias physocarpa has so far not invaded wildland in California. It could be expected to invade flood plains or other disturbed areas. In wet, tropical areas, such as Hawaii, it can form dense thickets in pastures. It is unlikely to do this in the drier climate of California. As a garden weed, it could trigger additional private treatment programs. It receives a Medium (2) in this category.

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 Asclepias physocarpa (Balloon Plant): Medium (12)**

-Low = 5-8 points

–Medium = 9-12 points

–High = 13-15 points

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

6) Post Entry Distribution and Survey Information: No official records indicating this species is established in the environment of California have been found, so it receives a Not Established (0) 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:

-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:

This plant is not known to be established in California. No official survey has been conducted to confirm its presence. However, it has been growing in the environment of California as a common garden plant and has never been noticed as invasive weed.

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, Asclepias physocarpa is medium risk. However, its low frequency in California after years of cultivation suggest that it will not become invasive, so a “C” rating is justified.

References:

Crop protection Compendium (Cabi). Accessed August 24, 2017: http://www.cabi.org/isc/datasheet/114618

Fishbein M., Chuba D., Ellison C., Mason-Gamer R. J., Lynch S. P. 2011. Phylogenetic relationships of Asclepias (Apocynaceae) inferred from non-coding chloroplast DNA sequences. Systematic Botany 36: 1008–1023. Missouri Botanical Garden online. Accessed August 24, 2017: http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=e373

Pest and Damage Record Database, California Department of Food and Agriculture, Plant Health and Pest Prevention Services. Accessed August 24, 2017: http://phpps.cdfa.ca.gov/user/frmLogon2.asp

South Africa National Biodiversity Institute, Plantzafrica, online. Accessed August 24, 2017: http://pza.sanbi.org/gomphocarpus-physocarpus

USDA Phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD). Accessed August 24, 2017.
https://pcit.aphis.usda.gov/pcit/

Weeds of Australia, Biosecurity Queensland, online. Accessed August 24, 2017. https://keyserver.lucidcentral.org/weeds/data/media/Html/gomphocarpus_physocarpus.htm

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

*NOTE:

You must be registered and logged in to post a comment. If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.

Photo of Ballon plant (Asclepias physocarpa), photographed in Tonga. Photo By: Tauʻolunga, via Wikimedia Commons

Pest Rating: C | Proposed Seed Rating: None

Posted by ls

A-Rated, Weeds

Alligatorweed | Alternanthera philoxeroides

October 17, 2017 Dean Kelch

California Pest Rating for

Alligatorweed | Alternanthera philoxeroides

Family: Amaranthaceae

Pest Rating: A | Proposed Seed Rating: R

PEST RATING PROFILE

Initiating Event:

There was a recent find of alligatorweed in Solano County; this is the first detection in northern California in many years.

History & Status:

Background: Alligatorweed is a perennial herb with horizontal to ascending stems to 1 m long, rooting at the nodes. The flowers are small and borne in small heads with white floral bracts. Like many aquatic emergent, it has distinctive submerged and emersed forms. The submerged form has hollow, floating, emergent and submerged stems. Terrestrial plants have solid stems. Typically, plants grow rooted in soil in shallow water and form dense, interwoven floating mats that extend over the surface of deeper water. Mats can become quite dense and nearly impenetrable. The floating mats can break away and follow currents to colonize new sites. Mats disrupt the natural ecology of a site by reducing light penetration and crowding out native species. Serious infestations can create anoxic, disease-promoting, and mosquito-breeding conditions.

Worldwide Distribution: This weed is found in wet, disturbed areas. It is also a weed of rice and sugar cane fields in tropical and subtropical regions. Native to southern Asia, alligatorweed is now found in tropical and subtropical regions around the world. It is considered an invasive species in Australia, China, New Zealand, and Thailand. Alligatorweed has been introduced throughout the southeastern United States from Virginia to Texas.

Official Control: Alligatorweed has had a CDFA rating of A as a pest in California for decades. The population in Los Angeles County has been managed intermittently over the years by the county, but it still persists. It has official status as a weed in Alabama, Arizona, Arkansas, California, Florida, South Carolina, and Texas.

California Distribution: Alligatorweed occurs in several southern California counties. It also has been detected in Contra Costa and Kings Counties, where it is eradicated. There was a recent find of 2 colonies in southern Solano County.

California Interceptions: Alligatorweed has been sent to CDFA by land managers.

The risk Alternanthera philoxeroides (alligatorweed) poses to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Risk is Medium (2), as the plant occurs in wetlands such as the Delta and creeks and rivers, as well as irrigation canals and watering ponds. These habitats are limited but widely distributed in California.

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: Most plants 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: Risk is Medium (2). Alligatorweed can spread rapidly via water movement and on boats and equipment as stem fragments. It is also grown as an aquarium plant and occasionally discarded into waterways. Seeds evidently are not produced in the United States.

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: Risk is High (3), as the plant can lower crop yields in rice fields, trigger state or international quarantines, and force changes in cultural practices by blocking canals. It has spread widely in the southeast, and has proven difficult to eradicate both there and in California. Its mats can improve habitat for mosquito larvae, leading to larger mosquito populations.

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

Economic Impact: A, C, D, E, G

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: Risk is High (3) as alligatorweed could further invade the water systems of California, disrupt natural wetland communities and potentially lower biodiversity by invading wetlands. The dense growth impedes water movement, blocks the growth of native plants, and reduces available habitat for water birds and fish. Its invasion in the Delta and its tributaries could degrade habitat of rare species such as Mason’s lilaeopsis (Lilaeopsis masonii), Sacramento River Chinook salmon (Oncorhynchus tshawytscha), and Giant garter snake (Thamnophis gigas). Its presence would trigger additional control measures.

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 Alternanthera philoxeroides (alligatorweed) : High (13)

-Low = 5-8 points

-Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Alligatorweed currently is known from 3-4 populations in northern and southern 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: Medium (11)

Uncertainty:

Uncertainty is low, as alligatorweed has established in wetlands in California and other states. There is some uncertainty as to the actual distribution of this plant in California, as, like some other aquatic weeds, it is likely to be overlooked.

Conclusion and Rating Justification:

Conclusions of the harm(s) associated with this pest to California using all of the evidence presented above:

Proposed Rating: Despite its limited ability to disperse between watersheds, this is a potentially significant weed in California of both natural wetlands and irrigation canals. Because of its potential economic impacts, it deserves an A rating, as it has proven tenacious and is actively spreading.

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.

Consortium of California Herbaria. Accessed 10/3/2017: ucjeps.berkeley.edu/consortium/

Florida Dept of Agriculture Weed of the Month: Alternanthera sessilis. Accessed 10/3/2017: http://www.freshfromflorida.com/Divisions-Offices/Plant-Industry/Plant-Industry-Publications/Weed-of-the-Month/April-2011-Alternanthera-Sessilis

Invasive Plant Atlas of the Mid-South. alligatorweed. Accessed 10/3/2017: https://www.gri.msstate.edu/ipams/species.php?CName=Alligatorweed

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.

*NOTE:

You must be registered and logged in to post a comment. If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.

Pest Rating: A | Proposed Seed Rating: R

Posted by ls

Weeds

Smallflower Hawksbeard | Crepis pulchra

September 12, 2017 Javaid Iqbal

California Pest Rating for

Crepis pulchra: Smallflower hawksbeard

Family: Asteraceae

Pest Rating: C | Proposed Seed Rating: R

PEST RATING PROFILE

Initiating Event:

Crepis pulchra had no previous pest rating; it has been reported in Napa, Solano and Contra Costa counties. A pest rating proposal is required to determine a permanent rating for this pest.

History & Status:

Background: Crepis pulchra is a flowering plant in the daisy family with the common name smallflower hawksbeard. Crepis pulchra is widespread in Europe, Central Asia and parts of Africa. It has become naturalized in the parts of United States and Canada¹. It is annual herb up to 40 inches tall with erect, glandular stem. One plant can produce up to 40 flower heads and each flower can produce 30 yellow ray florets. The leaves are alternate, toothed and the basal leaves are pinnately lobed. Flowering occurs from April to August. It can grow up to 3000 m elevation in dry open habitats, rolling grasslands, pastures, abandoned fields, waste areas, railroads and roadsides¹.

Worldwide Distribution: Crepis pulchra is widespread across much of Europe, Morocco, Algeria, western and central Asia. It has been reported in Ontario Canada and TX, OK, MO, AR, LA, MS, AL, FL, GA, SC, NC,VA, DE, WV, OH, IL, KY, TN & OR in the United States^3,1.

Official Control: Crepis pulchra is not declared or considered noxious by any state government authorities⁷.

California Distribution: Crepis pulchra currently is known in limited areas of Solano, Napa & Contra Costa counties².

California Interceptions: There were 8 vouchers submitted from Solano, Napa & Contra Costa counties between 1999 and 2011².

The risk Crepis pulchra (Smallflower hawksbeard) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: The plant has adapted to a wide area in the eastern states and Oregon. California has similar ecologically conditions as its native range, so it may be established on a larger but limited part of California. Therefore Crepis pulchra receives a Medium (2) 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: Most plants 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: Crepis pulchra reproduces only by seed; each plant can produce 40 seeded fruits⁵. These fruits are dispersed short distances by foraging animals, human activity or by wind. They may be dispersed longer distances by vehicles, on larger animals and in contaminated agricultural produce. It receives a 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: Crepis pulchra is a weed in some agricultural situations and it may reduce crop yield where it establishes. It receives a Low (1) in this category.

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

Economic Impact: A

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: Crepis pulchra has not yet spread widely in California. If it does spread, it might trigger new chemical treatments by ranchers and 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 Crepis pulchra (Smallflower hawksbeard): Medium (10)

–Low = 5-8 points

–Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Crepis pulchra has been reported in Napa, Solano & Contra Costa counties and seems likely to be restricted to this area at this time. 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: Medium (9)

Uncertainty:

Crepis pulchra has been present in California about 30 year ago and it is localized in a limited area. Due to its relatively noninvasive nature, there are limited chances that it will spread widely in California.

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 “C” rating is recommended, because of lake of evidence of its invasiveness.

References:

Flora of North America online. Accessed March 9, 2017 http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242416376
Jepson Herbarium. Online UC Berkeley. Accessed March 9, 2017 http://ucjeps.berkeley.edu/cgi-bin/get_consort.pl?taxon_name=Crepis%20pulchra
Plant profiles USDA Accessed March 9, 2017 https://plants.usda.gov/core/profile?symbol=CRPU3
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
Wildflower of the southeastern US. Accessed March 9, 2017 http://2bnthewild.com/plants/H270.htm
S. National Plant Germplasm System Accessed March 9, 2017 https://npgsweb.ars-grin.gov/gringlobal/taxonomydetail.aspx?id=310895
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.

*NOTE:

You must be registered and logged in to post a comment. If you have registered and have not received the registration confirmation, please contact us at 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.]

♦ Posted comments will not be able to be viewed immediately.

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Contain inappropriate language which is not germane to the pest rating proposal;

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Pest Rating: C | Proposed Seed Rating: R

Posted by ls

Weeds

Jeweled distaff thistle | Carthamus oxyacantha

July 20, 2017 Javaid Iqbal 2 Comments

Jewel distaff thistle (photo by Steve Hurst, hosted by the USDA-NRCS PLANTS Database)

California Pest Rating for

Jeweled distaff thistle | Carthamus oxyacantha

Family: Asteraceae

Pest Rating: B | Proposed Seed Rating: P

PEST RATING PROFILE

Initiating Event:

Jeweled distaff thistle was reported in California in the late 1970’s and had no previous pest rating. A pest rating proposal is required to determine a permanent rating for this pest.

History & Status:

Background: Jeweled distaff thistle is a spiny-leaved annual weed that can grow up to 1.5 m tall. Like other spiny plants in the genus Carthamus, this species is not eaten by livestock, enabling it to spread on grazing lands². The yellow flowers are born in flower heads approximately two to three cm in diameter and the leaves are covered with spines. It is a wild safflower relative found in arid and semi-arid environments in central and southern Asia⁵. It was collected in 1978 in Monterey County, California. It is considered by the United States Department of Food and Agriculture to be a noxious weed subject to eradication if found. Jeweled distaff thistle is a pernicious weed of agricultural lands especially, it reduces the yield of cereal crops. Jeweled distaff thistle most closely resembles cultivated safflower; it has smaller heads and much spinier leaves¹.

Worldwide Distribution: Jeweled distaff thistle is reported from Afghanistan, India, Iran, Iraq, Saudi Arabia, Syria, Kyrgyzstan, Uzbekistan, Pakistan, Azerbaijan, Armenia, Tajikistan and Turkmenistan⁴.

California Distribution: It was reported only in Monterey County, where it may be eradicated.

Official Control: Jeweled distaff thistle is listed as a harmful organism in

Colombia, Honduras and Mexico⁶. It is listed by U.S. Federal government as Noxious weed in Florida, Minnesota South Carolina, Massachusetts and Class

“A” Noxious weed for Alabama, North Carolina and Vermont⁷.

California Interceptions: Historically, only two vouchers were submitted in 1978 from Monterey County³.

The risk Carthamus oxyacantha (Jeweled distaff thistle) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Jeweled distaff thistle is adapted to central and southern Asia and similar climates. It may able to establish in a larger but limited part of California like Carthamus tinctorius. It receives a Medium (2) 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: Jeweled distaff thistle 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: Jeweled distaff thistle reproduces only by seed; each plant can produce up to 36 flower head that produces 15 to 20 single-seeded fruits⁵. These flower heads are dispersed short distances by foraging animals, human activity or by wind. They may be dispersed longer distances by vehicles, on larger animals and in contaminated agricultural produce. It receives a 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: Jeweled distaff thistle could invade crops, especially summer season crops in California. It could decrease crop yield and can lower the crop value, as it has been reported in its native range. Where adapted it displaces both native plants and other plants; this could negatively change normal cultural practices. It had spiny-tipped leaves with phyllaries heads which could injured the agriculturally important animals. 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: Jeweled distaff thistle has not yet spread widely in California. If it does spread, it might trigger new chemical treatments by ranchers and 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 Carthamus oxyacantha (Jeweled distaff thistle): Medium (12)**

–Low = 5-8 points

–Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Jeweled distaff thistle has been reported only in Monterey County and seems likely eradicated in this area. It receives a Low (-1) 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: Medium (11)

Uncertainty:

Jeweled distaff thistle has been known in California for decades, although it has not yet spread widely, there is nothing to stop it spreading in the appropriate habitats. There is some uncertainty as to how well it can spread in California if it escapes.

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 weed with a distribution in Monterey County. A “B” rating is recommended, as the plant is invasive and is a federal noxious weed.

References:

Flora of North America online Accessed April 26, 2017. http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=200023631
Federal Noxious Weed Dissminules of U.S. Accessed May 9, 2017. http://keys.lucidcentral.org/keys/FNW/FNW%20seeds/html/fact%20sheets/Carthamus%20oxyacantha.htm
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 May 9, 2017.
http://ucjeps.berkeley.edu/cgi-bin/get_consort.pl?taxon_name=Carthamus+oxyacantha&county=06053
US National Plant Germplasm system. Accessed May 9, 2017. https://npgsweb.ars-grin.gov/gringlobal/taxonomydetail.aspx?9239
Sullaiman Mohammed, Mohammad A Fredan 2015, American Journal of Environmental Sciences. Accessed May 9, 2017.
http://thescipub.com/PDF/ajessp.2015.125.132.pdf
USDA Phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD). Accessed May 9, 2017
https://pcit.aphis.usda.gov/pcit/
USDA Natural Resouces Conservation Services online. Accessed May 9, 2017
https://plants.usda.gov/core/profile?symbol=CAOX6

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.

NOTE:

You must be registered and logged in to post a comment. If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.

Pest Rating: B | Proposed Seed Rating: P

Posted by ls

Weeds

Laportea canadensis

July 18, 2017 Dean Kelch

Canadian wood-nettle and photographed at Brooklyn Botanic Garden in September — Canadian wood-nettle (Laportea canadensis), photographed at Brooklyn Botanic Garden (New York) in September. Photo By: Raffi Kojian (http://Gardenology.org) [CC BY-SA 3.0], via Wikimedia Commons

California Pest Rating for

Laportea canadensis)

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

PEST RATING PROFILE

Initiating Event:

This plant has been rated as “Q” by the CDFA Botany Lab in response to a border detection.

History & Status:

Wood nettle is a common perennial herb native to eastern North America, where it is found growing in moist to wet soil in the understory of Eastern Deciduous Forests. It has a strong family resemblance to the common nettle (Urtica dioica), but unlike most other members of the nettle family, it has alternate leaves. These leaves are broadly heart-shaped with a toothed margin. The plant is sparsely covered by stinging hairs. The effect of touching it is similar to touching common nettles, but not as severe. Native Americans used wood nettle to treat incontinence and tuberculosis, to counteract poison, as a love medicine, and to facilitate childbirth.

Official Control: There is no known official control at this time.

California Distribution: None.

California Interceptions: A new interception was made in Yolo County on 6/14/2017 (PDR NE0P06655513).

Consequences of Introduction:

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

Risk is Low (1), as the preferred habitat of wood nettle (moist, dense, deciduous forest) does not occur in California. Score: 1

– 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 plant produces numerous seeds that are apparently able to spread via water distribution. Patches may be the result of root sprouting. 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.

Economic Impact:

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: Risk is Low (1). No economic impact, even where it is common in Eastern North America.

– 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.

Environmental Impact:

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: Low (1). The plant is well integrated into its native landscape, and is not known to be weedy. It is unlikely to be adapted to any part of California.

– 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 wood nettle:

Add up the total score and include it here. (8)

–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. (0)

–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: (8)

Uncertainty:

Wood nettle is poorly adapted to California and it is not known to be weedy elsewhere; there is low uncertainty.

Conclusion and Rating Justification:

An Eastern woodland native. A D rating is recommended.

References:

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

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

Moerman, Daniel E. 1986. Medicinal plants of native America. Museum of Anthropology, University of Michigan, Ann Arbor.

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

NOTE:

You must be registered and logged in to post a comment. If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.

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

Posted by ls

Weeds

Branched Broomrape | Orobanche ramosa

July 18, 2017 Dean Kelch

California Pest Rating

Orobanche ramosa L., branched broomrape

Lamiales; Orobanchaceae

Pest Rating: A | Seed Rating: P

PEST RATING PROFILE

Initiating Event:

This plant has been rated as “A” on the CDFA Plant Pest Rating list for some years.

History & Status:

Branched broomrapes are annual plants that grow from seed and require a plant host to survive. It is a parasitic plant that grows on the roots of Broad-leaf hosts and obtains all of its nutrients and water from these plants. Seeds germinate in response to chemicals released by host plant roots. The broomrape seedling root then attaches itself to the host plant root and remains underground until flowering. The plant has no chlorophyll and no noticeable leaves. Flowering stems emerge from the ground about 6 weeks after germination; flowering and seed set occur within 2–3 weeks. Seed capsules dry and shatter in summer. One plant can produce over 100,000 seeds and seeds may lay dormant in the soil for more than 40 years. Broomrape seed can be spread by livestock, machinery, vehicles, flooding, and contaminated fodder, seed and soil. Branched broomrape is among the world’s worst crop weeds and poses a serious threat to the vegetable industry in California. It has been reported to attack 25 different crops including lettuce, tobacco, and tomatoes. Once established, branched broomrape can reduce crop yields by up to 70% and it is extremely difficult to eradicate. For this reason, it is often regulated and trading partners that import fresh host material may limit or exclude trade in these commodities.

Official Control: Branched broomrape has been an “A” listed noxious weed in California for many years. There was a state control and eradication program in California for branched broomrape that lasted over 20 years; it was discontinued in the late 1970s. It is also a federally listed noxious weed and is listed as noxious in Alabama, Arizona, Florida, Massachusetts, Minnesota, North Carolina, Oregon, South Carolina, Texas, and Vermont.

California Distribution: Branched broomrape was known from about a dozen infestations of agricultural fields in Central and Southern California. Most of these sites have been developed over the years and therefore the plant is likely eradicated at these sites (there have been no detections in over 30 years). A known extant infestation is in northern San Benito County; this population reappeared after more than 30 years, when the field was planted to tomatoes. A second occurrence was found in 2014 in San Joaquin County, in an area near known infestations from the 1970s.

California Interceptions: Vouchered specimens are known from Sacramento, Alameda, San Benito, San Joaquin, Santa Clara, and Ventura Counties.

United States: Branched broomrape has been found in California, Illinois, Kentucky, North Carolina, New Jersey, and Texas.

International: Branched broomrape is native to the Mediterranean. It is reported as naturalized and as an environmental and agricultural weed in Europe and western Asia. It has also been detected in Australia where they are transitioning from attempted eradication efforts to ongoing management.

This risk Branched broomrape would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: The plant has attacked crops in many countries spanning many climates. It is highly variable and this variation seems to be tied to differential ecological preferences. Therefore, It scores as High (3) in this category.

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

– 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 branched broomrape attacks 25 crop species and probably has the potential to attack many native species as well.

Evaluate the host range of the pest. Score:

– 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: Branched broomrape produces numerous seeds are documented to last for decades and are able to spread via equipment and on animals (including humans). The seed bank is highly persistent. Branched broomrape receives a High (3) in this category.

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

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

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).

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: Branched broomrape receives a High (3) in this category. Branched broomrape can lower crop productivity in susceptible row crops by up to 70%. This can affect land value and result in quarantine.

– 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.

Environmental Impact: A, B, 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.

Score the pest for Environmental Impact.

Environmental Impact Score: Branched broomrape receives a High (3) in this category. Branched broomrape is likely to trigger new treatments by land managers. The plant has not yet spread to the wild in California. However, certain native plants such as clovers (Trifolium) are likely susceptible to branched broomrape. These include such rare or endangered species as showy Indian clover (T. amoenum), Buck’s clover (T. buckwestiorum), and Monterey clover (Trifolium trichocalyx).

– 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 Branched broomrape: 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: Branched broomrape has been recently found in three counties in California, but may be eradicated. It 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: High (13)

Uncertainty:

The experience in the mid 20^th century of California and in Australia show the potential of this species to disrupt crop systems. Its effects on the environment are more speculative and necessarily more uncertain.

Conclusion and Rating Justification:

A terrible agricultural weed because of its ability to produce large numbers of long-lived seeds and its ease of spread. It deserves an A rating as it is likely to have a high impact if it spreads again in California. Development has removed most known sites, but it is otherwise difficult to treat.

References:

Consortium of California Herbaria: ucjeps.berkeley.edu/consortium/

Cooke, D. 2002. Control of branched broomrape; a literature review. Animal and Plant Control Commission of South Australia.

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

NSW Department of Primary Industries. Weed alert; branched broomrape: http://www.dpi.nsw.gov.au/agriculture/pests-weeds/weeds/profiles/broomrapes

USDA Plants Database, Orobanche ramosa: http://plants.usda.gov/core/profile?symbol=orra

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

NOTE:

You must be registered and logged in to post a comment. If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.

Pest Rating: A | Proposed Seed Rating: P

Posted by ls

Weeds

Myrtle Spurge | Euphorbia myrsinites

July 17, 2017 Dean Kelch

California Plant Pest Rating for

Myrtle Spurge (Euphorbia myrsinites)

Pest Rating: A | Proposed Seed Rating: R

PEST RATING PROFILE

Initiating Event:

Collection in Lassen County by county staff and submission to the CDFA Botany Lab.

History & Status:

Background: Myrtle spurge is a deciduous, perennial herb (to 10 cm tall by 40 cm wide) native to southeastern Europe through Asia Minor. It is a semi-succulent plant with prostrate branches and awl-shaped, blue leaves without a petiole approximately 2 cm long. The flowers (cyathia) are borne in spring. The floral bracts are bright greenish yellow. Like all true spurges, the branches and leaves exude an irritating white latex when damaged. It arrived in CA as a garden plant, and it can be found at nurseries in the north and at higher elevations. It’s is extremely cold hardy, but evidently doesn’t thrive in areas with severe summer drought.

California Distribution: Myrtle spurge is currently restricted in California. There are 2 small populations, persisting but not spreading, known along the coast in Alameda and Ventura Counties. It was once collected in Kern County. A small population in Quincy, Plumas County has evidently been eradicated. The recent find, in Lassen County, is reportedly spreading from nearby cultivation. A similar case exists east of Macarthur, Shasta County.

United States: Myrtle spurge is highly invasive in Utah and other western, interior states including Wyoming, Colorado, Eastern Oregon, Washington and New Mexico. It has also been collected as waif in a few eastern states such as Wisconsin and Virginia.

International: Myrtle spurge is native to southeastern Europe through Asia Minor.

Regulation: Myrtle spurge is listed as a noxious weed in Colorado, Oregon, Washington and Utah.

This risk Myrtle spurge will 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 Medium (2), as the plant could naturalize throughout higher elevation mountains and in the “sagebrush” area of northeastern 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) 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: 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 Medium (2). The plant reproduces via numerous, rather large seeds that are thrown some distance from the mother plant. Nevertheless, its ability to disperse seems limited, as populations do not spread rapidly. It is unlikely to be found in commercial crop seed.

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 High (3) as Myrtle spurge, where established, lowers the rangeland productivity, is unpalatable to livestock, and, where common, will necessitate herbicide treatments for control. As it is a noxious weed in several western states, infested commodities could be excluded from those states that list it as noxious.

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

Economic Impact: A, 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

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, Myrtle spurge could disrupt natural bunchgrass and sagebrush scrub communities. Once established, it would trigger additional treatment programs to control it, as in Utah. It would crowd out native species that coexist with or foster rare species.

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

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

Environmental Impact: B, C, D

A. The pest could directly affect threatened or endangered species

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

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

D. 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 Myrtle spurge:

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: High (13).

Score: 0

–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: 13

Uncertainty:

Because there is ample evidence of its invasiveness in Utah, Oregon and Colorado, there is little uncertainty that this plant can establish and become invasive in similar climatic areas of California.

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. It has the ability to spread more widely in California. Its current limited distribution in California makes the feasibility of eradication high. An A rating is justifed.

References:

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

Global Compendium of Weeds: http://www.hear.org/gcw/species/euphorbia_myrsinites/

Jepson Flora Project (eds.) 2013. Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html, accessed on Mar 28 2014

Washington State Weed Control Board; Myrtle Spurge. Accessed 6/18/2017: http://www.nwcb.wa.gov/weeds/myrtle-spurge

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

NOTE:

You must be registered and logged in to post a comment. If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.

Pest Rating: A | Proposed Seed Rating: R

Posted by ls

Weeds

Sahara Mustard | Brassica tournefortii

July 14, 2017 Dean Kelch 1 Comment

California Pest Rating for

Brassica tournefortii Gouan. | Sahara mustard

Pest Rating: C | Proposed Seed Rating: R

PEST RATING PROFILE

Initiating Event:

This plant has been rated as “Q” by CDFA botany staff.

History & Status:

The genus Brassica comprises about 40 species and many agricultural cultivars such as cabbage, mustard, bok choi, brussel sprouts, canola, broccoli, turnip, etc. Sahara mustard, as the name implies, is a species adapted to dry, sandy soils.

Sahara mustard forms a basal rosette like most mustards from which grows a highly branched inflorescence with hundreds of typical mustard 4-parted yellow flowers. The basal leaves generally have more than a dozen pairs of lobes or leaflets; this is more than is typical for most other Brassica spp. As the plant fruits, it dies. The dense tangle of stems and fruits breaks off at ground level and tumbles over the ground in windy situations, releasing seeds as it moves through the landscape. The seeds sometimes occur as a contaminant in agricultural seed lots and they are easily distinguishable from other mustard seeds.

Official Control: Some land managers control this plant, but where it is adapted it is generally too common to control it well.

California Distribution: Sahara mustard is known from at least 15 counties in California; most are in the southern California. It is very common in warm desert regions.

California Interceptions: Sahara mustard was first collected in California in the 1920s from the Coachilla Valley. From that region, it has spread widely to surrounding areas.

United States: Sahara mustard is known from California, Texas, New Mexico, Arizona, and Nevada in the United States.

International: Sahara mustard occurs in all of North Africa from Morocco through Egypt, in southern Europe, and through Western Asia. It is an introduced weed in Australia.

Consequences of Introduction:

1) Climate/Host Interaction: Risk is Mediium (2), as the plant is naturalized on roadsides in the desert and then moves into open desert from these areas. More recent finds in coastal California indicates that it may invade southern coastal areas as well.

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) Known 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 Medium (2). The plant produces a large number of seeds that spread along roads. It then spreads into the desert interior via the “tumbleweed” inflorescences. It is especially good at exploiting sandy soils.

Evaluate the natural and artificial dispersal potential of the pest.

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: The presence of this plant in the Anza Borrego desert impacts the spring wildflower tourist industry, as the plant outcompetes native wildflowers that form the basis of an important tourist industry. If it infests row crops or irrigated areas, it lowers crop value or crop yield.

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

Economic Impact: A, B, C, 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: Risk is High (3) as the plant is able to dominate desert areas that are home to sensitive species such as desert tortoise, blunt-nosed leopard lizard, and many rare native plants.

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 Sahara mustard: High (13)

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: Sahara mustard has been found in many counties in California, most commonly in the south. It has spread widely during the last 20 years in California. It receives a High (-3) 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: Medium (10)

Uncertainty:

Given that populations of Sahara mustard have exploded in the last 20 years, uncertainty is low. It only remains to be seen how well it can invade the Mediterranean coastal and central regions of California. The likelihood is that it has fully invaded the areas where it is best adapted and newer incursions will occur, but that they will prove to be limited.

Conclusion and Rating Justification:

Although Sahara mustard may be somewhat limited in its spread by its environmental preferences, it has shown itself quite invasive where it is adapted. Because it is so widespread, especially in the desert areas, it should be given a C rating.

References:

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

Berry, K. H., T. A. Gowan, D.M. Miller & M. L. Brooks. 2014. Models of Invasion and Establishment for African Mustard (Brassica tournefortii). Invasive Plant Science and Management 7: 599-616.

Bhagirath S. Chauhan, Gurjeet Gill, and Christopher Preston (2006) African mustard (Brassica tournefortii ) germination in southern Australia. Weed Science: September 2006, Vol. 54, No. 5, pp. 891-897.

Cal_IPC website. Sahara mustard (Brassica tournefortii) research. Accessed 12/17/2015: http://www.cal-ipc.org/ip/research/saharan/index.php

Consortium of California Herbaria: ucjeps.berkeley.edu/consortium/

Malusa, J., B. Halvorson, and D. Angell. 2003. Distribution of the exotic mustard Brassica tournefortii in the Mohawk Dunes and Mountains, Arizona. Desert Plants 19:31–36.

Sanders, A., & R. Minnich. 2000. Brassica tournefortii. in Bossard, C. C., J. M. Randall, and M. M. Hochovsky. Invasive Plants of California’s Wildlands. University of California Press, Berkeley, CA.

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

NOTE:

You must be registered and logged in to post a comment. If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.

Pest Rating: C | Proposed Seed Rating: R

Posted by ls

Weeds

Orange Hawkweed | Hieracium aurantiacum

July 6, 2017 Javaid Iqbal

California Pest Rating for

***Hieracium aurantiacum*: Orange hawkweed**

Family : Asteraceae

Pest Rating : B | Proposed Seed Rating: P

PEST RATING PROFILE

Initiating Event:

Orange hawkweed had no previous pest rating, it has been reported in Nevada, Siskiyou, and Mono counties. A pest rating proposal is required to determine a permanent rating for this pest.

History & Status:

Background: Orange hawkweed is a fibrous rooted perennial herb in the Aster family (Asteraceae) that grows 10-36 inches tall. It blooms in late spring to early summer and produces bright orange to orange-red ray flowers with 5 to 30 flower heads. Flower heads close every evening and reopen at mid-morning each day prior to seeding. Every flower head can produce between 12 and 50 small brown or black single seeded fruit and has a hairy tuff at one end that allows the seed to be carried by the wind. Flower stems are bare, all plant parts contain a milky juice and leaves are covered with stiff hairs. Orange hawkweed, like all invasive hawkweeds, has a shallow and fibrous root system and underground creeping rhizomes.The plant rosettes also originate from aboveground stolons (resembling those of strawberry). The stolons are capable of producing new plants where the runners contact soil; therefore, patch expansion is accomplished primarily by stolon growth and/or rhizomes. Long distance spread is mostly by wind and water borne seed or by seeds carried in and on wildlife and livestock^2,3.

The scientific name Hieracium is of Greek origin and means ‘hawk’. Hawkweed refers to the fact that many species of this genus grow at high altitudes that are only accessible by hawks. It spread rapidly in North America after its introduction as an ornamental and/or as a contamination of pasture seeds from its native range in Europe¹.

Worldwide Distribution: Orange hawkweed is native to Europe it grows; in subalpine areas resulting in a disjunct distribution¹. It has spread to most of Europe and in southern Russia. Due to its use as a garden ornamental and rock garden plant, it was introduced into exotic locations including New Zealand, Tasmania, Japan, Canada, Australia and North America^1,3.

Official Control: Orange hawkweed is listed as a harmful organism in Korea⁵. It is prohibited entry to Australia, New Zealand and the USA. Orange hawkweed is deemed a noxious weed in Oregon, Washington, Idaho, Montana and British Columbia. This makes it unlawful to transport, propagate and sell in these localities³.

California Distribution: Orange hawkweed has been reported from Siskiyou, Nevada and Mono counties.

California Interceptions: One PDR (470P06027609 from Siskiyou County) was reported in the Pest and Damage Record Database by CDFA⁴. There are five vouchers from Siskiyou , Nevada and Mono counties documented between 1967 and 2013. Only the Siskiyou County population seemed adventive.

The risk Hieracium aurantiacum (Orange hawkweed) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Orange hawkweed is well established in Oregon and Washington, and is spreading there. These states have similar habitat to northern California. Therefore, there is a high risk that it will establish in this part of California. It receives a Medium (2) 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) Pest Host Range: Orange hawkweed does 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: Orange hawkweed reproduces and spreads through prolific seed production, as well as vegetatively through stolons, and rhizomes. Under ideal conditions, one plant can spread and infest an area two to three feet in diameter in its first year of growth. Seeds can be dispersed by wind, water, or “hitch-hiking” and are often moved in contaminated soil associated with transplanting new plants into gardens and flowerbeds². Seeds are able to germinate immediately after dropping from the plant and can remain viable in the soil for up to seven years³. It receives a High (3) in this category.

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: Orange hawkweed is invasive in natural or lawn environments in high latitude and altitude areas. It can form mats that prevent the growth of forest understory plants. Orange hawkweed monocultures may degrade forest rangeland, reducing the amount of forage available to livestock³. It receives a Low (1) in this category.

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

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: Orange hawkweed is an aggressive competitor for space, light, and soil nutrients. It has been reported to be allelopathic, producing phytotoxic chemicals in pollen grains that inhibit seed germination, seedling emergence and regeneration of other plants². Rare taxa that might be affected include species such as Kincaid’s lupine (Lupinus sulphureus ssp. kincaidii),Fender’s Blue Butterfly (Plebejus icarioides ssp. fendri) and Humboldt milk–vetch (Astragalus agnicidus).

It receives a High(3) in this category.

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, home/urban gardening or ornamental plantings.

Environmental Impact Score: (3) cultural practices

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 Orange hawkweed:

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 current distribution in California: Medium (12).

6) Post Entry Distribution and Survey Information: Orange hawkweed has been reported in Mono, Siskiyou and Nevada counties and may be eridicate at this time. It receives a Low (-1) 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 based on introduction score minus the post entry distribution and survey information Score: (11)

Uncertainty:

Orange hawkweed has been present in California about 30 years and it is localized in a limited area. It has the potential to spread to more acreage and may be eradicated at this time. It is likely that this plant will come to dominate many new areas and increase its density and distribution.

Conclusion and Rating Justification:

Conclusions of the harm associated with this pest to California using all of the evidence presented above: Based on the score listed above, Orange hawkweed is a Medium risk. Although it is only medium risk in California, it is possible to keep it out of the State with modest effort. Given this, and its ability to spread widely and displace native plants, a “B” rating is proposed.

References:

Ghislaine Cortat CABI online Orange hawkweed. Accessed 4-25-17. http://www.cabi.org/isc/datasheet/27160
Oregon Department of Agriculture Plant Pest Risk Assessment for Orange hawkweed, Hieracium aurantiacum Accessed 4-25-2017. https://www.oregon.gov/ODA/shared/Documents/Publications/Weeds/PlantPestRiskAssessmentOrangeHawkweed.pdf
US Forest Services Fact Sheet. Accessed 4-25-2017. https://www.na.fs.fed.us/fhp/invasive_plants/weeds/orange-hawkweed%20.pdf
Pest and Damage Record Database, California Department of Food and Agriculture, Plant Health and Pest Prevention Services. Accessed 4-25-2017 http://phpps.cdfa.ca.gov/user/frmLogon2.asp
USDA Phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD). Accessed 4-25-2017. 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.

NOTE:

You must be registered and logged in to post a comment. If you have registered and have not received the registration confirmation, please contact us at plant.health[@]cdfa.ca.gov.

Pest Rating : B | Proposed Seed Rating: P

Posted by ls

Weeds

Yellow-Flag Iris | Iris pseudacorus L.

April 7, 2017 Javaid Iqbal

California Pest Rating for

Yellow-Flag Iris | Iris pseudacorus L.

Family: Iridaceae

Pest Rating: B | Proposed Seed Rating: R

PEST RATING PROFILE

Initiating Event:

Iris pseudacorus was introduced in California in the early 1950’s and had no previous pest rating. A pest rating proposal is required to determine a permanent rating for this pest.

History & Status:

Background: Iris pseudacorus, commonly called yellow-flag iris, is a rhizomatous beardless wetland iris that is native to Europe, northern Asia, the Middle East and northern Africa. It has naturalized in much of North America, particularly in the eastern U.S. It is at home in wet soils, typically forming large colonies along streams, ponds and marshes².

Iris pseudacorus is a perennial, emergent aquatic plant ranging from 0.5–1.5 m in height. It has bright yellow flowers (3-4” across), with a darker yellow zone and brown or violet veining on each fall. It blooms in late spring to early summer on rigid, upright, branched stalks. Each flower stalk bears 4-12 flowers. Flowers give way to large seed pods⁴. Plant roots have been used in the past for a variety of purposes including medical treatments, dyes, inks, and snuff. Plant seeds have been used as a coffee substitute with no caffeine².

Worldwide Distribution: Iris pseudacorus is native to all the countries of Europe except Iceland; it is also native to the Caucasus Mountains, Western Asia and North Africa. In North America, it has been reported in Canada from Newfoundland to British Columbia. It is present in the majority of the United States, with the exception of a handful of western and mid-western states⁴. Iris pseudacorus has been reported from Delaware, Maryland, North Carolina, Oregon, Tennessee, Virginia, Washington, Wisconsin, West Virginia and all New England states^3,4.

Official Control: Iris pseudacorus is listed as noxious weed in these states: CN, MA, MN, NH, OR and WA ⁷.

California Distribution: Iris pseudacorus is reported from Sacramento, San Diego, Solano, Siskiyou, Merced, San Luis Obispo, Contra Costa, Butte, Los Angeles, Shasta, San Mateo, Monterey, San Bernardino, Ventura, Santa Barbara, Kern, Mendocino, Riverside, Orange and Madera counties³.

California Interceptions: Two PDR’s (413865 Siskiyou and 1349823 Contra Costa) were reported in the Pest and Damage Record Database by CDFA⁵. There were 69 vouchers from all over the California submitted since the 1990’s.

The risk Iris pseudacorus (Yellow-flag iris) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Iris pseudacorus could grow on wet soil and it is highly adapted to acidic soil. The overall California climate is perfect fit for its ability to spread aggressively in wetlands. Its widespread distribution demonstrates its ability to occupy wetlands. Therefore, Iris pseudacorus receives a Medium (2) 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: Iris pseudacorus 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: Iris pseudacorus propagate via seed and rhizomes. The corky seeds are buoyant, with 95% of them able to float for up to 2 months and germinate along shore edges; they typically do not germinate while immersed in water. The thick, tuberous rhizomes spreads radially to produce large clonal populations of up to several hundred flowering “stems”. Rhizomes can split to produce up to 10 plants per year. These rhizomes are drought tolerant, but during floods, both rhizomes and seeds may be washed downstream⁴. 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: Iris pseudacorus can impede irrigation and swimming. It may be reduce flow and block irrigation systems and flood control ditches. Its seeds can clog pipes and water control structures. Removal of plant material from these systems may require herbicides or excavation equipment and can be costly⁴.

It can cause gastroenteritis in cattle if ingested, and it contains glycosides that can cause skin irritation in wildlife that come in contact with this plant⁵.

It receives a Medium (2) in this category.

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

Economic Impact: F, G

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: Iris pseudacorus could invade the water systems of California, disrupt natural lake communities and potentially lower biodiversity by dominating lake margins. This vegetative growth can also trap sediment, raise the local elevation of the ecosystem, and alter wetland hydrology. The clonal nature of Iris pseudacorus causes it to form dense stands that 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), San Diego ambrosia (Ambrosia pumila) and water howellia (Howelia aquatilis). Iris pseudacorus 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

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 Iris pseudacorus (Yellow-flag iris): High (13)

–Low = 5-8 points

–Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Iris pseudacorus is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas. 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 (11)

Uncertainty:

Iris pseudacorus has been in California a long time, but has spread slowly in wetlands. It has the potential to spread to more acreage and it is likely that this plant will come to dominant many new areas and increase its density and distribution.

Conclusion and Rating Justification:

A bad weed in wetlands in California. Deserves a “B” rating as it has invaded many areas to which it is adapted and undoubtedly has the ability to spread further. Because of this potential future harm, a “B” rating is justified.

References:

Connick, S. and M. Gerel. Partnering to prevent invasions of plants of horticultural origin. California Invasive Plant Council Symposium 2004. Ventura, CA. Accessed February 10, 2017 http://www.cal-ipc.org/ip/management/plant_profiles/Iris_pseudacorus.php

Missouri Botanical Garden on line. Accessed February 15, 2017 http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=c797

Jepson Herbarium. Online UC Berkeley. Accessed February 15, 2017 http://ucjeps.berkeley.edu/cgi-bin/get_smasch_county.pl?taxon_id=29301

Morgan, V.H., L. Berent and A. Fusaro. Glansis online. Accessed February 15, 2017. https://nas.er.usgs.gov/queries/greatlakes/FactSheet.aspx?SpeciesID=1115&Potential=N&Type=0

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 February 15, 2017. https://pcit.aphis.usda.gov/pcit/

USDA data for State Noxious weeds. Accessed March 1, 2017 https://plants.usda.gov/java/noxComposite?stateRpt=yes

Author:

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

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: B | Proposed Seed Rating: R

Posted by ls

Weeds

Kidneyleaf Mud Plantain | Heteranthera reniformis

March 30, 2017 Raj Randhawa

California Pest Rating for

Kidneyleaf mud plantain | Heteranthera reniformis

Liliales: Pontedriaceae

Pest Rating: A | Proposed Seed Rating: P

PEST RATING PROFILE

Initiating Event:

Heteranthera reniformis has a current rating of Q. A pest rating proposal is required to designate a permanent rating for this species.

History & Status:

Background: Heteranthera reniformis, commonly known as kidneyleaf mud plantain is native to the fresh water wetlands of eastern North, Central and South America (Arakaki, Derek 2013). It is submerged or floating, annual or facultative perennial plant that grows 15-20 cm tall in fresh water less than 15 cm deep and on damp soil at water’s edge. The stems can grow along the mud under the water, with leaves and stems emerging. Roots occur at nodes along the stems (NSW Weedwise 2014). In North America, its flowering mainly starts in July, but the plant can flower from late May to September and can continue until frost (Csurhes, Steve 2016). This species has been listed as endangered in the states of Illinois and Ohio (USDA Natural Resource Conservation District, 2017).

H. reniformis prefers open, sunny sites with nutrient rich soils. It is commonly found in roadside ditches and in wet soils, on edges of fresh water streams, rivers and ponds, on fresh water tidal mudflats and along powerline corridors (Business Queensland, 2016). This species can grow rapidly to form dense mats when competition is low, but it is a poor competitor with taller sedges and rushes. It will grow well for a few years on the edges of the ponds and marshes before being shaded out. Since its stems can produce roots at each node, any broken segments with more than one node can be washed downstream to infest new areas (Csurhes, Steve 2016).

Worldwide Distribution: Heteranthera reniformis is naturalized in Italy, Spain and Australia. It is also distributed in parts of Mexico, Dominican Republic, Jamaica, Belize, Costa Rica, El Salvador, Honduras, Nicaragua, Panama, Guatemala, Columbia, Puerto Rico, Ecuador, Argentina, Brazil, Peru, Venezuela and Paraguay (Pacific Island Ecosystem at Risk, 2009). It has been found growing on the borders of rice fields in northern Italy (Csurhes, Steve 2016).

US Distribution: North Central US: Illinois, Missouri; Northeastern US: Connecticut, Indiana, New Jersey, New York, Ohio, Pennsylvania, West Virginia; South Central US: Texas; Southeastern US: Alabama, Delaware, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, South Carolina, Tennessee, Virginia. (GRIN Taxonomy Database). There are approximately 200 collection sites listed in herbarium records for Heteranthera reniformis. Documented occurrences exist in: New York (22), West Virginia (5), Ohio (1), Illinois (2). It is also reported in Alabama (1), Arkansas (six counties), Georgia (5), Iowa (one county), North Carolina (two, maybe twelve, counties), South Carolina (3) (Nature Serve 2015).

Official Control: Heteranthera reniformis is considered as high risk weed in Hawaii (Arakaki, Derek 2013) and is a weed of special concern in Connecticut (USDA Natural Resource Conservation District, 2017). It is listed as an agricultural weed, spreading in Europe (Csurhes, Steve 2016). This species is also listed as weed in Portugal and Spain (Global Compendium of Weeds 2007).

California Distribution: Heteranthera reniformis was found once in Glenn County at the national wildlife reserve in 2011 (PDR# 1597375) (CDFA Pest and Damage Records Database, 2017).

California Interceptions: Hateranthera reniformis has not been intercepted through regulatory pathways by CDFA.

The risk Hateranthera reniformis, Kidneyleaf mud plant, would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Heteranthera reniformis grows in roadside ditches, on the edges of fresh water streams/rivers and ponds, in fresh water tidal mudflats, sinkholes, along powerline corridors and at an elevation of up to 2600 m in its native range. It has a strong potential to grow in similar areas of California but it would be limited to freshwater wetland and shallow water margins. Favorable conditions for its growth and expansion include recently inundated areas following flooding, beaver dams, rice fields or human activities in the state (Nature Serve 2015). It receives a Medium (2) 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: Heteranthera reniformis does not require one particular host but grows wherever ecological conditions are favorable. However, it is a poor competitor with many sedges, rushes and other wetland species and can be easily crowded out of wetlands (Pacific Island Ecosystem at Risk 2009). It receives a Medium (2) 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: Heteranthera reniformis reproduces both vegetatively and by seed. Its stem fragments can produce root at each node and produce new plants. These stem fragments can be washed downstream and infest new areas. A single flood event is likely to disperse stem fragments over a considerable distance. Each fruit contain 8-14 winged seeds and these seeds are likely dispersed by winds and water. Seed banks may persist in soil for many years. Plant fragments can also move to new location in mud stuck to animals or vehicles (NSW Weedwise 2014, Csurhes, Steve 2016). 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: Heteranthera reniformis is reported as a weed of flooded rice where yield reduction of up to 70% have been recorded in experimental plots (Csurhes, Steve 2016). In Hawaii, this species has already proved to be a problematic species in Oahu taro fields and may outcompete newly planted taro, resulting in reduced yields (Arakaki, Derek 2013). If reniformis were to introduce and establish in California, it is likely to impact rice growing areas of Sacramento and northern San Joaquin valley counties. Since it can cover shallow water surfaces, it is likely to interfere with water supply to irrigation fed agricultural areas. Use of herbicides to control infestations is likely to increase crop production costs in rice growing areas of California. It receives a High (3) in this category.

Economic Impact: A, B, G

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: Heteranthera reniformis is likely to form dense mats and colonize open shallow waters in disturbed wetlands of California. This can make this weed a potential threat to state’s native vegetation and fresh water aquatic habitats. Its preferred habitat of sunny sites, nutrient rich soils and shallow water is present in Northern and Central coast of California; this makes it easy to grow and establish in those areas. It can grow quickly in recently inundated areas, where there is little competition with natives. It can persist and exclude natives in these situations. If it establishes, mechanical removal and need of herbicide applications can trigger additional chemical treatments. It receives a High (3) in this category.

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

Environmental Impact: A, 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 Heteranthera reniformis, Kidneyleaf mud plant: High (13)**

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: Heteranthera reniformis has been found once growing in natural environment of California and 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: Medium (12)

Uncertainty:

Although Heteranthera reniformis can grow rapidly in fresh water and on damp soils but it does not grow well in shaded areas and does not compete well with tall sedges and rushes. Early detection and surveys in fairly disturbed habitats, along ditches and margins of ponds and open mudflats in California may confirm the distribution of this species. Similar species such as H.limosa and the non-native H.rotundifolia complicate identification. Therefore it may be more widespread than is currently known.

Conclusion and Rating Justification:

Heteranthera reniformis is a medium risk weed and has a broad native range, from tropical to sub-tropical areas. This species thrives in various habitats and can become highly invasive, especially when the competition is low. If this species spreads in California, it can quickly dominate disturbed and wetland land habitats. An “A” rating is justified, as eradication is possible with attention to management.

References:

Arakaki, Derek. 2013. Pest Advisory No. 13-0. Hawaii Department of Agriculture. Accessed: 02/15/2017 https://hdoa.hawaii.gov/pi/files/2013/01/Heteranthera-reniformis.pdf

Business Queensland. 2016. Weeds and Diseases. Kidneyleaf mudplantain. Accessed: 02/15/2017 https://www.business.qld.gov.au/industries/farms-fishing-forestry/agriculture/land-management/health-pests-weeds-diseases/weeds-diseases/other/kidneyleaf-mudplantain

Csurhes, Steve. 2016. Invasive plant risk assessment: Kidneyleaf mudplantain. Department of Agriculture and Fisheries. Biosecurity Queensland. Accessed: 02/15/2017 https://www.daf.qld.gov.au/__data/assets/pdf…/IPA-Kidneyleaf-Risk-Assessment.pdf

Nature Serve. 2015. NatureServe Explorer: An online encyclopedia of life [web application. NatureServe, Arlington, Virginia. Accessed: 02/15/2017 http://explorer.natureserve.org

NSW Weedwise 2014. Department of Primary Industries. Kidney-leaf mud plantain. Accessed: 02/14/2017 http://weeds.dpi.nsw.gov.au/Weeds/Details/188

Randell, Rod 2007. Global Compendium of Weeds. Heteranthera reniformis (Pontederiaceae). Accessed: 02/14/2017 http://www.hear.org/gcw/species/heteranthera_reniformis/

Pacific Island Ecosystem at Risk (PIER) 2009. PIER Species lists: Heteranthera reniformis. Accessed: 02/14/2017 http://www.hear.org/pier/species/heteranthera_reniformis.htm

Pest and Damage Record Database, Plant Health and Pest Prevention Services, CA Department of Food and Agriculture. Assessed Date: 02/13/2017 https://pdr.cdfa.ca.gov/PDR/pdrmainmenu.aspx

USDA Natural Resource Conservation District. 2017. Plant profile: Heteranthera reniformis Ruiz & Pav. Accessed: 02/13/2017 https://plants.usda.gov/core/profile?symbol=HERE

US National Plant Germplasm System. GRIN Taxonomy Database. Heteranthera reniformis Ruiz and Pav. Accessed: 02/16/2017 https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysearch.asp

Author:

Raj Randhawa, California Department of Food and Agriculture

Responsible Party:

Dean G. Kelch, Primary Botanist; California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 654-0317; plant.health[@]cdfa.ca.gov.

Pest Rating: A | Proposed Seed Rating: P

Posted by ls

Weeds

Lily of the Valley Vine | Salpichroa origanifolia

March 23, 2017 Javaid Iqbal

California Pest Rating for

Lily of the Valley Vine | Salpichroa origanifolia

Family: Solanaceae

Pest Rating: C | Proposed Seed Rating: R

PEST RATING PROFILE

Initiating Event:

Salpichroa origanifolia was introduced in California in the early 1930’s and had no previous pest rating. A pest rating proposal is required to determine a permanent rating for this pest.

History & Status:

Background: Salpichroa origanifolia is a species of flowering plant in the Solanaceae family known by the common names lily of the valley vine, pampas lily-of-the-valley or cock’s-eggs. Salpichroa origanifolia is a weed of urban areas where it grows on home sites and neglected areas, trailing over fences and low bushes³. It is native to South America and is naturalized in Africa, Australasia, Europe, and North America¹.

Salpichroa origanifolia is a fast growing creeping herbaceous plant or woody vine with scrambling or trailing stems produced from a long-lived woody rootstock. It has oval shaped leaves that are hairy, with leaf stalks about the same length as the leaf blades. Flowers are bell-shaped, whitish in color, 6 – 8mm long form at the leaf axils. These flowers generally have a drooping or nodding appearance. Flowering occurs throughout the year, but is most prolific during summer. The fruit is an elongated or egg-shaped berry with a smooth surface. These berries (10-20 mm long and 7-8 mm wide) turn yellow or whitish in color as they mature and each contains several seeds. The seeds are brown to pale yellow in color, flattened, rounded in shape (about 2 mm across), and surrounded in a sticky substance⁶.

Salpichroa origanifolia was sold in CA nurseries in the early 20^th century. Although it has not been common in nurseries for decades, it has shown itself to be particularly resistant after establishment. Some plants are likely adventive, but most collection document plants that were likely planted.

Worldwide Distribution: Salpichroa origanifolia is native to South America, originating from Argentina and Uruguay. It has naturalized overseas in Europe (included UK, Croatia, France, Ireland, Portugal, Spain & Italy), Africa, New Zealand and Australia. In the United States, it is reported in Virginia, North Carolina, South Carolina, Georgia, Florida, Louisiana, Texas, New Mexico, Arizona and California^{1, 7}.

Official Control: Salpichroa origanifolia is not declared or considered noxious by any state government authorities⁶. However, in Tasmania it is regarded as a toxic weed and its sale and distribution are illegal¹.

California Distribution: Salpichroa origanifolia is reported from Alameda, San Diego, Solano, San Luis Obispo, Contra Costa, Butte, Los Angeles, Monterey, San Bernardino, Ventura, Santa Barbara, Riverside, Orange, San Benito, San Francisco, Sonoma, Yolo, Marin, Humboldt, San Joaquin, Santa Clara, Colusa, Napa and Yuba counties³.

California Interceptions: Two PDR’s (1450405 and 1251122) were reported in the Pest and Damage Record Database by CDFA⁵. There have been155 vouchers from all over California submitted since 1930’s.

The risk Salpichroa origanifolia (Lily of the valley vine) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Salpichroa origanifolia is native to an area with a very similar climate to parts of California. It has the ability to naturalized in urban areas, forest, woodland and riparian vegetation. It is usually limited in coverage however. Therefore, Salpichroa origanifolia receives a Medium (2) 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: Salpichroa origanifolia does 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: This species reproduces by seeds and vegetatively from creeping underground stems (i.e. rhizomes) and suckering roots. Root fragments and pieces of underground stems are spread during soil moving activities and in dumped garden waste. It produces about 2000 seeds per plant which are dispersed by soil and plant movement and animals that eat the fruits of this plant like birds, rats, mice and ants⁷.Despite this, it has not spread from the sites of introduction. It receives a 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: Salpichroa origanifolia is not known as an agricultural weed, but it could be a problematic weed in home gardening and grazing land in the State. Therefore, it could negatively change the normal cultural practices. 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: Salpichroa origanifolia is locally highly invasive and smothers neighboring vegetation, killing large shrubs and fruit trees, and making vegetable and flower culture difficult⁴. It produce dense stand that could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes. Its invasive nature create a monoculture that could affect the rare taxa like, Humboldt milk–vetch (Astragalus agnicidus), Abruptbeak sedge (Carex abrupta), showy Indian clover (Trifolium amoenum), and San Diego ambrosia (Ambrosia pumila). It 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

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 Salpichroa origanifolia (Lily of the valley vine): Medium (11)

–Low = 5-8 points

–Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information: Salpichroa origanifolia is scattered but widespread in California and might spread more given enough time. It receives a High (-3) in this category.

Score: -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:

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

Uncertainty:

Salpichroa origanifolia has been known in California a long time. It spread very slowly. This plant could invade many new areas and increase its density and acreage or it may continue to spread slowly the arears where it is establish. There is moderate 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 weed with a distribution in at least 24 counties. A “C” rating is recommended, as the plant is widely distributed, but could spread further.

References:

Crop protection Compendium. Search for invasive species. Online Accessed February 21, 2017. http://www.cabi.org/isc/datasheet/116862

Encyclopedia of Life. Online Accessed February 21, 2017. http://eol.org/pages/581082/overview#cite_note-TasGov-2

Jepson Herbarium. Online UC Berkeley. Accessed February 21, 2017 http://ucjeps.berkeley.edu/cgi-bin/get_smasch_county.pl?taxon_id=43020

Monash University, Invasive species online.
Accessed February 21, 2017 http://invasivespecies.org.au/traction/permalink/wra2111

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 February 15, 2017. https://pcit.aphis.usda.gov/pcit/

Weed of Australia, Biosecurity Queensland Edition. Accessed February 21, 2017 https://keyserver.lucidcentral.org/weeds/data/media/Html/salpichroa_origanifolia.htm

Author:

Javaid Iqbal, California Department of Food and Agriculture

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