Geraniales: Geraniaceae

California Pest Rating for

Geranium lucidum L.: Shining cranesbill

Pest Rating: A | Proposed Seed Rating: R

PEST RATING PROFILE

Initiating Event:

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

History & Status:

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

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

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

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

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

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

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

Consequences of Introduction:

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

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

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

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

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

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

Evaluate the host range of the pest:

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

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

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

Evaluate the natural and artificial dispersal potential of the pest:

Score: 3

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

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

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

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

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

Economic Impact: B, C, D

A. The pest could lower crop yield.

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

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

D. The pest could negatively change normal cultural practices.

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

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

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

Economic Impact Score: 3

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

– Medium (2) causes 2 of these impacts.

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

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

It receives a High (3) in this category

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

Environmental Impact: A, C, D

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

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

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

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

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

Environmental Impact Score: 3

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

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

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

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

Add up the total score and include it here:

-Low = 5-8 points

-Medium = 9-12 points

–High = 13-15 points

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

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

Score: -1

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

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

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

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

Final Score:

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

Uncertainty:

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

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

Conclusion and Rating Justification:

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

References:

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

Responsible Party:

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