California Pest Rating for
Pest Rating: A | Proposed Seed Rating: P
PEST RATING PROFILE
This plant has been rated as “A” on the CDFA Plant Pest Rating list for many years.
History & Status:
Bearded creeper is a winter annual, with erect, openly branched flowering stems to 60 cm tall at maturity. Most germination occurs after the first significant rains of fall/early winter, but germination can continue throughout the rainy season. Fall germinating plants exist as basal rosettes until flowering stems bolt in spring. Rosette leaves wither as flowering commences in late spring/early summer. Bearded creeper is adapted to many environmental conditions, is highly competitive for water and nutrients, and often produces solid stands. This adaptation to various conditions may be because it has been introduced from several locations in southern Europe. Although not an aggressive species in its native habitats, its adaptation to rough grazing lands of the Mediterranean region renders it invasive in natural grasslands of western North America. Here it contributes to degradation of native plant communities, lower forage production and increased risk of soil erosion.
Official Control: As Bearded creeper has been an “A” listed noxious weed for years, most or all of the few historic localities have been treated and eradicated.
California Distribution: Modoc Plateau, North Coast Ranges (Sonoma Co.); to 250 m (850 ft).
California Interceptions: Vouchered specimens are known from Modoc and Sonoma Counties.
United States: Bearded creeper is known also from Idaho, Oregon, and Washington.
International: Bearded creeper is native to Europe. It is reported as naturalized and as an environmental weed in Canada.
This risk Bearded creeper would pose to California is evaluated below.
Consequences of Introduction:
1) Climate/Host Interaction: The plant has adapted to a wide range of habitats in its native range and is demonstrated to have had multiple introductions into Western North America. Therefore bearded creeper receives a 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 weeds do not require any one host, but grow wherever ecological conditions are favorable.
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: Bearded creeper produces via numerous seeds that seem to be able to spread rather slowly. The seed bank is moderately persistent. Once established, bearded creeper can persist and has proven difficult to eradicate. Bearded creeper receives a Medium (2) 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: Bearded creeper can lower range productivity, land value, and can trigger state quarantines. Bearded creeper receives a High (3) in this category.
Evaluate the economic impact of the pest to California using the criteria below. Score:
A. The pest could lower crop yield.
B. The pest could lower crop value (includes increasing crop production costs).
C. The pest could trigger the loss of markets (includes quarantines).
D. The pest could negatively change normal cultural practices.
E. The pest can vector, or is vectored, by another pestiferous organism.
F. The organism is injurious or poisonous to agriculturally important animals.
G. The organism can interfere with the delivery or supply of water for agricultural uses.
– Low (1) causes 0 or 1 of these impacts.
– Medium (2) causes 2 of these impacts.
– High (3) causes 3 or more of these impacts.
5) Environmental Impact: Bearded creeper is likely to trigger new chemical treatments by ranchers and land managers. The plant can dominate grassland and vernal pool areas, excluding native plants and lowering biodiversity. Rare taxa that might be affected include grassland species such as showy Indian clover (Trifolium amoenum), CA filaree (California macrophylla), and vernal pool species such as Burke’s goldfields (Lasthenia burkei) and CA tiger salamander (Ambystoma californiense). The plant can disrupt natural communities and exclude cultural plants from a landscape. Bearded creeper receives a High (3) in this category.
Evaluate the environmental impact of the pest on California using the criteria below.
A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.
B. The pest could directly affect threatened or endangered species.
C. The pest could impact threatened or endangered species by disrupting critical habitats.
D. The pest could trigger additional official or private treatment programs.
E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.
Score the pest for Environmental Impact. Score:
– 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 Bearded creeper: High (14)
Add up the total score and include it here.
–Low = 5-8 points
–Medium = 9-12 points
–High = 13-15 points
6) Post Entry Distribution and Survey Information: Bearded creeper has been found in in 2 counties in California. It 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.
–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.
The final score is the consequences of introduction score minus the post entry distribution and survey information score: High (13)
Limited dispersability and fast treatment response has restricted bearded creeper’s spread so far in CA. However, it has shown great ability to spread if neglected, as in OR & ID.
Conclusion and Rating Justification:
A very bad weed. Deserves an A rating as all known populations have been treated. Chances of state eradication are high with sustained efforts.
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 (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.
Garnatje, T., R. Vilatersana, C. T. Roché, N. Garcia-Jacas, A. Susanna & D. C. Thill. 2002. Multiple introductions from the Iberian peninsula are responsible for invasion of Crupina vulgaris in western North America. New Phytologist 154: 419-28.
Invasive Species Compendium; Crupina vulgaris: http://www.cabi.org/isc/datasheet/13697
Thill, D.C., C.T. Roche and D.L. Zamora. 1999. Common crupina. Pp. 189-201. In, Biology and Management of Noxious Rangeland Weeds. Eds. R.L. Sheley and J.K. Petroff, Oregon State Univ. Press, Corvallis.
Dean G. Kelch, Primary Botanist; California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 654-0312; plant.health[@]cdfa.ca.gov.
The 45-day comment period opened on July 8, 2016 and closes on Aug 22, 2016.
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Consequences of Introduction: 1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]
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Pest Rating: A | Proposed Seed rating: P
Posted by ls