Securigera varia -- Oregon

Evaluation Summary

Evaluation Date: 2022-12-14

Screener: Justine Casebolt

Plant: Securigera varia

Common Name(s):

Purple crownvetch, trailing crownvetch

State: Oregon

PRE Score: 14

Questions Answered: 20

Screener Confidence (%): 75

Executive Summary

Commonly known as crown vetch, Securigera varia (syn. Coronilla varia) is a perennial herb from the legume family. Native to the Mediterranean region, it was introduced and established in the United States between the 1950s and 1980s as ground cover and for soil erosion along roadways and in strip mining. It has been introduced and become established outside its native range in 14 other countries or islands including Europe, Australia, and New Zealand. Securigera varia is widespread throughout the US and Europe and can tolerate a diversity of climates. It's trailing stems can spread aggressively, reaching heights of one meter, and has been shown to crowd out native plant species. It primarily spreads vegetatively from small above ground stems with nodes and through rhizomes when provided with adequate moisture. Research has shown that seed viability is low, which indicates that vegetative reproduction is the primary form of reproduction. Due to its aggressive vegetative spread, it can be difficult to eradicate once it has established in an area. More research is needed to evaluate the seed germination timing and long-term seed viability. Also, there is lack of scientific evidence to suggest the plant's propagules spread by wind, water, or animals. However, considering its ability to spread aggressively from cut stems and rhizomes there is potential for it to be spread long distances by attaching to equipment and vehicles. Based on the results of this evaluation, Securigera varia received a total PRE score of 14, which puts it at moderate potential risk.

Climate Matching Map

Climate Matching Map PDF

Attachment	Size
ClimateMatch_OR_Securigera_varia.pdf (1.15 MB)	1.15 MB

1. Question 1

Yes or No

Yes

Points

1

Confidence

Very High

Answer / Justification

Securigera varia is a herbaceous perennial legume native to the Mediterranean region (Losure et al., 2009; Molano-Flores, 2014) and has been introduced and become established outside it's native range in 14 other countries or islands including the North America, Europe, Australia, and New Zealand. It was introduced to the US between the 1950s and 1980s as ground cover and to control soil erosion along roads and in strip mining (Gustine & Moyer, 1990; Losure et al., 2009).

Reference(s)

Molano-Flores, Brenda. 2014. “An Invasive Plant Species Decreases Native Plant Reproductive Success”. Natural Areas Journal 34: 465-69. doi:https://doi-org.proxy.lib.pdx.edu/10.3375/043.034.0408.

“Securigera Varia (L.) Lassen in GBIF Secretariat”. 2022 2022. GBIF. https://www.gbif.org/species/5350000.

Losure, David A, Kirk A. Moloney, and Brian J Wilsey. 2009. “Modes of Crown Vetch Invasion and Persistence”. The American Midland Naturalist 161: 232-42. https://bioone-org.proxy.lib.pdx.edu/journals/the-american-midland-naturalist/volume-161/issue-2/0003-0031-161.2.232/Modes-of-Crown-Vetch-Invasion-and-Persistence/10.1674/0003-0031-161.2.232.full.

Gustine, D. L., and B. G. Moyer. 1990. “Crownvetch (Coronilla Varia L.)”. In Biotechnology in Agriculture and Forestry, 10:341–354. Berlin, Heidelberg: Springer Berlin Heidelberg. doi:10.1007/978-3-642-74448-8_15.

2. Question 2

Yes or No

Yes

Points

2

Confidence

Very High

Answer / Justification

Yes, it is found in areas with similar climate to Oregon (temperate mountain to temperate desert from USDA zones 4-11). It is well distributed throughout the US in areas with similar climate to Oregon such as Washington, Northern California, Idaho, Nevada, Utah, and areas of the eastern US. It is also found in other countries with similar climate such as Europe, Australia, and New Zealand.

Reference(s)

“Securigera Varia (L.) Lassen in GBIF Secretariat”. 2022 2022. GBIF. https://www.gbif.org/species/5350000.

3. Question 3

Yes or No

Yes

Points

2

Confidence

Very High

Answer / Justification

Yes, it is known as being invasive throughout the US (Molano-Flores, 2014; Losure et al., 2009) and it was found to be invasive in Nova Scotia, Canada (Flynn et al., 2013). According to the Climate Matching tool and GBIF, its has been reported across the US. It is known as a threat to natural areas due to it ability to spread aggressively forming thick monocultures that can crowd out native plant species (Losure et al., 2009; Symstad, 2004). Several states have listed it as invasive including Oregon, Alaska, Georgia, South Carolina, Wisconsin, Indiana, West Virginia, Kentucky, West Virginia, Virginia, and Maryland (Invasive Plant Atlas of the United States).

Reference(s)

Molano-Flores, Brenda. 2014. “An Invasive Plant Species Decreases Native Plant Reproductive Success”. Natural Areas Journal 34: 465-69. doi:https://doi-org.proxy.lib.pdx.edu/10.3375/043.034.0408.

Losure, David A, Kirk A. Moloney, and Brian J Wilsey. 2009. “Modes of Crown Vetch Invasion and Persistence”. The American Midland Naturalist 161: 232-42. https://bioone-org.proxy.lib.pdx.edu/journals/the-american-midland-naturalist/volume-161/issue-2/0003-0031-161.2.232/Modes-of-Crown-Vetch-Invasion-and-Persistence/10.1674/0003-0031-161.2.232.full.

Flynn, Andrea, Anthony G. Miller, and David J. Garbary. 2013. “Coronilla Varia L. (Fabaceae): AN INVADER OF A COASTAL BARRIER BEACH IN NOVA SCOTIA, CANADA”. Proceedings of the Nova Scotian Institute of Science (NSIS) 47. doi:10.15273/pnsis.v47i2.4339.

Symstad, Amy J. 2004. “Secondary Invasion Following the Reduction of Coronilla Varia (crownvetch) in Sand Prairie”. The American Midland Naturalist 152: 183-89. https://bioone-org.proxy.lib.pdx.edu/journals/the-american-midland-naturalist/volume-152/issue-1/0003-0031_2004_152_0183_SIFTRO_2.0.CO_2/Secondary-Invasion-Following-the-Reduction-of-Coronilla-varia-Crownvetch-in/10.1674/0003-0031(2004)152[0183:SIFTRO]2.0.

Rojas-Sandoval, Julissa. 2019. “Securigera Securidaca”. CABI Compendium CABI Compendium: 117016. doi:10.1079/cabicompendium.117016.

“Purple Crown-Vetch: Securigera Varia (Fabales: Fabaceae): Invasive Plant Atlas of the United States”. n.d. https://www.invasiveplantatlas.org/subject.html?sub=3015.

4. Question 4

Yes or No

Yes

Points

3

Confidence

High

Answer / Justification

Yes, it is noted as being invasive in areas of similar climate to Oregon within the US (Molano-Flores, 2014; Losure et al., 2009) and Nova Scotia, Canada (Flynn et al., 2013). More specifically, it is noted as being invasive in West Virginia, Kentucky, Georgia, West Virginia, Virginia, and Maryland where the climate is similar to Oregon (Invasive Plant Atlas of the United States).

Reference(s)

“Securigera Varia (L.) Lassen in GBIF Secretariat”. 2022 2022. GBIF. https://www.gbif.org/species/5350000.

Molano-Flores, Brenda. 2014. “An Invasive Plant Species Decreases Native Plant Reproductive Success”. Natural Areas Journal 34: 465-69. doi:https://doi-org.proxy.lib.pdx.edu/10.3375/043.034.0408.

Losure, David A, Kirk A. Moloney, and Brian J Wilsey. 2009. “Modes of Crown Vetch Invasion and Persistence”. The American Midland Naturalist 161: 232-42. https://bioone-org.proxy.lib.pdx.edu/journals/the-american-midland-naturalist/volume-161/issue-2/0003-0031-161.2.232/Modes-of-Crown-Vetch-Invasion-and-Persistence/10.1674/0003-0031-161.2.232.full.

Flynn, Andrea, Anthony G. Miller, and David J. Garbary. 2013. “Coronilla Varia L. (Fabaceae): AN INVADER OF A COASTAL BARRIER BEACH IN NOVA SCOTIA, CANADA”. Proceedings of the Nova Scotian Institute of Science (NSIS) 47. doi:10.15273/pnsis.v47i2.4339.

“Purple Crown-Vetch: Securigera Varia (Fabales: Fabaceae): Invasive Plant Atlas of the United States”. n.d. https://www.invasiveplantatlas.org/subject.html?sub=3015.

5. Question 5

Yes or No

No

Points

0

Confidence

Low

Answer / Justification

There is a lack of evidence that other species from the genus Securigena are invasive. Securigera securidaca was found in the Global Compendium of Weeds Digital Library and is not listed as invasive.

Reference(s)

No references cited.

6. Question 6

Yes or No

No

Points

0

Confidence

Very High

Answer / Justification

Based on the climate match results, this species is widespread and grows in a variety of different climates. It is found all throughout the US and Europe, which indicates it can tolerate a diversity of climates.

Reference(s)

“Securigera Varia (L.) Lassen in GBIF Secretariat”. 2022 2022. GBIF. https://www.gbif.org/species/5350000.

Molano-Flores, Brenda. 2014. “An Invasive Plant Species Decreases Native Plant Reproductive Success”. Natural Areas Journal 34: 465-69. doi:https://doi-org.proxy.lib.pdx.edu/10.3375/043.034.0408.

Losure, David A, Kirk A. Moloney, and Brian J Wilsey. 2009. “Modes of Crown Vetch Invasion and Persistence”. The American Midland Naturalist 161: 232-42. https://bioone-org.proxy.lib.pdx.edu/journals/the-american-midland-naturalist/volume-161/issue-2/0003-0031-161.2.232/Modes-of-Crown-Vetch-Invasion-and-Persistence/10.1674/0003-0031-161.2.232.full.

Symstad, Amy J. 2004. “Secondary Invasion Following the Reduction of Coronilla Varia (crownvetch) in Sand Prairie”. The American Midland Naturalist 152: 183-89. https://bioone-org.proxy.lib.pdx.edu/journals/the-american-midland-naturalist/volume-152/issue-1/0003-0031_2004_152_0183_SIFTRO_2.0.CO_2/Secondary-Invasion-Following-the-Reduction-of-Coronilla-varia-Crownvetch-in/10.1674/0003-0031(2004)152[0183:SIFTRO]2.0.

7. Question 7

Yes or No

Yes

Points

1

Confidence

Very High

Answer / Justification

Yes, Securigera varia has been reported to have both direct and indirect impacts to native species (Molano-Flores, 2014). It's trailing stems can spread aggressively via seed and vegetatively, forming thick monocultures that can crowd out native plant species (Losure et al., 2009; Symstad, 2004). In both field and greenhouse studies, it has been shown to suppress growth and flowering of a rare native plant, Solidago shortii (Asteraceae), in northeastern Kentucky (Walck et al. 1999). It can also increase the availability of nitrogen in the soil, which alter the nutrient cycle and affect ecosystem dynamics (Symstad, 2004).

Reference(s)

Molano-Flores, Brenda. 2014. “An Invasive Plant Species Decreases Native Plant Reproductive Success”. Natural Areas Journal 34: 465-69. doi:https://doi-org.proxy.lib.pdx.edu/10.3375/043.034.0408.

Losure, David A, Kirk A. Moloney, and Brian J Wilsey. 2009. “Modes of Crown Vetch Invasion and Persistence”. The American Midland Naturalist 161: 232-42. https://bioone-org.proxy.lib.pdx.edu/journals/the-american-midland-naturalist/volume-161/issue-2/0003-0031-161.2.232/Modes-of-Crown-Vetch-Invasion-and-Persistence/10.1674/0003-0031-161.2.232.full.

Symstad, Amy J. 2004. “Secondary Invasion Following the Reduction of Coronilla Varia (crownvetch) in Sand Prairie”. The American Midland Naturalist 152: 183-89. https://bioone-org.proxy.lib.pdx.edu/journals/the-american-midland-naturalist/volume-152/issue-1/0003-0031_2004_152_0183_SIFTRO_2.0.CO_2/Secondary-Invasion-Following-the-Reduction-of-Coronilla-varia-Crownvetch-in/10.1674/0003-0031(2004)152[0183:SIFTRO]2.0.

Walck, Jeffrey L., Jerry M. Baskin, and Carol C. Baskin. 1999. “Effects of Competition from Introduced Plants on Establishment, Survival, Growth and Reproduction of the Rare Plant Solidago Shortii (Asteraceae)”. Biological Conservation 88: 213-19. doi:10.1016/S0006-3207(98)00097-4.

8. Question 8

Yes or No

No

Points

0

Confidence

Medium

Answer / Justification

Securigera varia is a herbaceous trailing legume that can grow up to a one meter in height (Molano-Flores, 2014) and primarily spreads vegetatively through rhizomes (Symstad, 2004). I could not find any evidence that Securigera varia promotes large-scale fires or alters the fire regime. There is a lack of research regarding this topic.

Reference(s)

Molano-Flores, Brenda. 2014. “An Invasive Plant Species Decreases Native Plant Reproductive Success”. Natural Areas Journal 34: 465-69. doi:https://doi-org.proxy.lib.pdx.edu/10.3375/043.034.0408.

Symstad, Amy J. 2004. “Secondary Invasion Following the Reduction of Coronilla Varia (crownvetch) in Sand Prairie”. The American Midland Naturalist 152: 183-89. https://bioone-org.proxy.lib.pdx.edu/journals/the-american-midland-naturalist/volume-152/issue-1/0003-0031_2004_152_0183_SIFTRO_2.0.CO_2/Secondary-Invasion-Following-the-Reduction-of-Coronilla-varia-Crownvetch-in/10.1674/0003-0031(2004)152[0183:SIFTRO]2.0.

9. Question 9

Yes or No

Yes

Points

1

Confidence

High

Answer / Justification

It contains β-nitropropionic acid, which is a neurotoxin (Campbell, 2006; Majak & Bose, 1976). This toxin inhibits succinate dehydrogenase, which is a key enzyme in the Kreb cycle and the electron transport chain resulting in neurotoxicity and even death in humans and livestock (Francis et al., 2013). This toxin can also affect birds, voles, chicks, horses and other non-ruminant animals (Campbell, 2006; Shenk et al., 1976; Yerlikaya et al., 2021). Symptoms can include reduced food intake, weight loss, and abnormal behavioral symptoms. Most reports of β-nitropropionic acid poisoning in domestic animals were caused from the consumption of Astragalus species (from same family-Fabaceae) (Ludolph et al., 1991). Other than the studies provided, I could not find any other evidence that Securigera varia is specifically consumed in high doses resulting in toxicity or death in humans, fish, or other grazing animals.

Reference(s)

Campbell, Terry W. 2006. “Crown Vetch (Coronilla Varia) Poisoning in a Budgerigar (Melopsittacus Undulatus)”. Journal of Avian Medicine and Surgery 20: 97-100. https://bioone-org.proxy.lib.pdx.edu/journals/journal-of-avian-medicine-and-surgery/volume-20/issue-2/2005-009.1/Crown-Vetch-Coronilla-varia-Poisoning-in-a-Budgerigar-Melopsittacus-undulatus/10.1647/2005-009.1.full.

Shenk, J. S., P. J. Wangsness, R. M. Leach, D. L. Gustine, J. L. Gobble, and R. F. Barnes. 1976. “Relationship Between β-Nitropropionic Acid Content of Crownvetch and Toxicity in Nonruminant Animals”. Journal of Animal Science 42: 616-21. doi:10.2527/jas1976.423616x.

Majak, Walter, and Robert J. Bose. 1976. “Nitropropanylglucopyranoses in Coronilla Varia”. Phytochemistry 15: 415-17. doi:10.1016/S0031-9422(00)86835-1.

Francis, Kevin, Crystal Smitherman, Shirley F. Nishino, Jim C. Spain, and Giovanni Gadda. 2013. “The Biochemistry of the Metabolic Poison Propionate 3-Nitronate and Its Conjugate Acid, 3-Nitropropionate”. IUBMB Life 65: 759-68. doi:10.1002/iub.1195.

Yerlikaya, Serife, Mehmet Cengiz Baloglu, Yasemin Celik Altunoglu, Alina Diuzheva, J\ ozsef Jek\H o, Zolt\ an Czi\ aky, and Gokhan Zengin. 2021. “Exploring of Coronilla Varia L. Extracts As a Source of High-Value Natural Agents: Chemical Profiles and Biological Connections”. South African Journal of Botany 143: 382-92. doi:10.1016/j.sajb.2021.02.025.

Ludolph, A. C., F. He, P. S. Spencer, J. Hammerstad, and M. Sabri. 1991. “3-Nitropropionic Acid - Exogenous Animal Neurotoxin and Possible Human Striatal Toxin”. Canadian Journal of Neurological Sciences 18: 492-98. doi:10.1017/S0317167100032212.

10. Question 10

Yes or No

No

Points

0

Confidence

Medium

Answer / Justification

There is a lack of evidence that Securigera varia forms impenetrable thickets, blocking or slowing the movement of animals. This is a herbaceous legume that can grow up to a one meter in height (Molano-Flores, 2014) so it can be inferred that the chances of blocking animal movements is fairly low.

Reference(s)

Molano-Flores, Brenda. 2014. “An Invasive Plant Species Decreases Native Plant Reproductive Success”. Natural Areas Journal 34: 465-69. doi:https://doi-org.proxy.lib.pdx.edu/10.3375/043.034.0408.

11. Question 11

Yes or No

Yes

Points

1

Confidence

Very High

Answer / Justification

Yes, research suggests that even small fragments are capable of spreading vegetatively by rhizomes. Above ground stems with a node can also generate new plants with proper moisture. Scott and Mason (1992) characterize Securigera varia by it's ability to spread extensively by rhizomes and found that it had the greatest initial spread by it's third summer of growth when compared to other rhizomatous legumes.

Reference(s)

Losure, David A, Kirk A. Moloney, and Brian J Wilsey. 2009. “Modes of Crown Vetch Invasion and Persistence”. The American Midland Naturalist 161: 232-42. https://bioone-org.proxy.lib.pdx.edu/journals/the-american-midland-naturalist/volume-161/issue-2/0003-0031-161.2.232/Modes-of-Crown-Vetch-Invasion-and-Persistence/10.1674/0003-0031-161.2.232.full.

Scott, D., and C. R. Mason. 1992. “Potential for High Country Pasture Improvement from Planting of Rhizome Fragments of Spreading Legumes”. Proceedings of the New Zealand Grassland Association, 127-29. doi:10.33584/jnzg.1992.54.2044.

12. Question 12

Yes or No

Yes

Points

1

Confidence

High

Answer / Justification

Yes, the research suggests that this is a common method of reproduction. In a controlled lab setting, Losure et al. (2009) documented Securigera varia ability to propagate from fragments of the above ground stem. They found that any above ground stem section with a node can generate a new plant suggesting that asexual reproduction is more common than sexual reproduction. Losure et al. (2009) also suggest that this could be the mechanism behind why mowing is shown to be an ineffective method of control for Securigera varia (Symstad, 2002).

Reference(s)

Losure, David A, Kirk A. Moloney, and Brian J Wilsey. 2009. “Modes of Crown Vetch Invasion and Persistence”. The American Midland Naturalist 161: 232-42. https://bioone-org.proxy.lib.pdx.edu/journals/the-american-midland-naturalist/volume-161/issue-2/0003-0031-161.2.232/Modes-of-Crown-Vetch-Invasion-and-Persistence/10.1674/0003-0031-161.2.232.full.

Scott, D., and C. R. Mason. 1992. “Potential for High Country Pasture Improvement from Planting of Rhizome Fragments of Spreading Legumes”. Proceedings of the New Zealand Grassland Association, 127-29. doi:10.33584/jnzg.1992.54.2044.

Symstad, Amy J. 2004. “Secondary Invasion Following the Reduction of Coronilla Varia (crownvetch) in Sand Prairie”. The American Midland Naturalist 152: 183-89. https://bioone-org.proxy.lib.pdx.edu/journals/the-american-midland-naturalist/volume-152/issue-1/0003-0031_2004_152_0183_SIFTRO_2.0.CO_2/Secondary-Invasion-Following-the-Reduction-of-Coronilla-varia-Crownvetch-in/10.1674/0003-0031(2004)152[0183:SIFTRO]2.0.

13. Question 13

Yes or No

No

Points

0

Confidence

High

Answer / Justification

The evidence suggests that vegetative reproduction is the primary form of reproduction. Losure et al. (2009) failed to find viable seeds in the soil samples taken from two established patches of Securigera varia.

Reference(s)

Losure, David A, Kirk A. Moloney, and Brian J Wilsey. 2009. “Modes of Crown Vetch Invasion and Persistence”. The American Midland Naturalist 161: 232-42. https://bioone-org.proxy.lib.pdx.edu/journals/the-american-midland-naturalist/volume-161/issue-2/0003-0031-161.2.232/Modes-of-Crown-Vetch-Invasion-and-Persistence/10.1674/0003-0031-161.2.232.full.

Scott, D., and C. R. Mason. 1992. “Potential for High Country Pasture Improvement from Planting of Rhizome Fragments of Spreading Legumes”. Proceedings of the New Zealand Grassland Association, 127-29. doi:10.33584/jnzg.1992.54.2044.

14. Question 14

Yes or No

No

Points

0

Confidence

Very High

Answer / Justification

The evidence suggests that seed viability is low each year.

Reference(s)

Losure, David A, Kirk A. Moloney, and Brian J Wilsey. 2009. “Modes of Crown Vetch Invasion and Persistence”. The American Midland Naturalist 161: 232-42. https://bioone-org.proxy.lib.pdx.edu/journals/the-american-midland-naturalist/volume-161/issue-2/0003-0031-161.2.232/Modes-of-Crown-Vetch-Invasion-and-Persistence/10.1674/0003-0031-161.2.232.full.

Scott, D., and C. R. Mason. 1992. “Potential for High Country Pasture Improvement from Planting of Rhizome Fragments of Spreading Legumes”. Proceedings of the New Zealand Grassland Association, 127-29. doi:10.33584/jnzg.1992.54.2044.

15. Question 15

Yes or No

No

Points

0

Confidence

High

Answer / Justification

Successful seed recruitment is rare, Losure et al. (2009) found no viable seeds in two established dense patches of Securigera varia. However, the seeds of Securigera varia can remain dormant and viable in the soil for over 15 years (Padureanu, 2011)

Reference(s)

Losure, David A, Kirk A. Moloney, and Brian J Wilsey. 2009. “Modes of Crown Vetch Invasion and Persistence”. The American Midland Naturalist 161: 232-42. https://bioone-org.proxy.lib.pdx.edu/journals/the-american-midland-naturalist/volume-161/issue-2/0003-0031-161.2.232/Modes-of-Crown-Vetch-Invasion-and-Persistence/10.1674/0003-0031-161.2.232.full.

adureanu, Silvica P\u. 2011. “Morphological Characterization and the Germinating Potential of Coronilla Varia L. Pollen”. Agronomy Series of Scientific Research Lucrari Stiintifice Seria Agronomie 54. http://www.uaiasi.ro/revagrois/PDF/2011-2/paper/pagini_84-89_Padureanu.pdf.

16. Question 16

Yes or No

No

Points

0

Confidence

Low

Answer / Justification

Plants are slow to establish, requiring 2-3 years for overall coverage (Gustine & Moyer, 1990), however, seed viability is shown to be low (Losure et al., 2009; Scott & Mason, 1992). Scott and Mason (1992) indicate that it can take 4 to 7 years for the species "to become apparent in a sward." More research is needed to examine when and if the plant will establish it's first viable seeds, which is why the confidence level is low.

Reference(s)

Gustine, D. L., and B. G. Moyer. 1990. “Crownvetch (Coronilla Varia L.)”. In Biotechnology in Agriculture and Forestry, 10:341–354. Berlin, Heidelberg: Springer Berlin Heidelberg. doi:10.1007/978-3-642-74448-8_15.

Losure, David A, Kirk A. Moloney, and Brian J Wilsey. 2009. “Modes of Crown Vetch Invasion and Persistence”. The American Midland Naturalist 161: 232-42. https://bioone-org.proxy.lib.pdx.edu/journals/the-american-midland-naturalist/volume-161/issue-2/0003-0031-161.2.232/Modes-of-Crown-Vetch-Invasion-and-Persistence/10.1674/0003-0031-161.2.232.full.

Scott, D., and C. R. Mason. 1992. “Potential for High Country Pasture Improvement from Planting of Rhizome Fragments of Spreading Legumes”. Proceedings of the New Zealand Grassland Association, 127-29. doi:10.33584/jnzg.1992.54.2044.

17. Question 17

Yes or No

Yes

Points

1

Confidence

High

Answer / Justification

Yes, it can flower and produce seed for an entire growing season and it is common to find new flowers and mature fruits within the same patch.

Reference(s)

Losure, David A, Kirk A. Moloney, and Brian J Wilsey. 2009. “Modes of Crown Vetch Invasion and Persistence”. The American Midland Naturalist 161: 232-42. https://bioone-org.proxy.lib.pdx.edu/journals/the-american-midland-naturalist/volume-161/issue-2/0003-0031-161.2.232/Modes-of-Crown-Vetch-Invasion-and-Persistence/10.1674/0003-0031-161.2.232.full.

18. Question 18

Yes or No

No

Points

0

Confidence

Low

Answer / Justification

There is a lack of evidence to suggest that the propagules are frequently dispersed long distances by mammals, bird, or other domestic animals.

Reference(s)

No references cited.

19. Question 19

Yes or No

No

Points

0

Confidence

Low

Answer / Justification

There is a lack of evidence to suggest that the plant's propagules are frequently dispersed long distances by wind or water. It usually grows in dry and dry-mesic sand prairie upland habitat, so the chances of spreading by water are most likely low (Molano-Flores, 2014).

Reference(s)

Molano-Flores, Brenda. 2014. “An Invasive Plant Species Decreases Native Plant Reproductive Success”. Natural Areas Journal 34: 465-69. doi:https://doi-org.proxy.lib.pdx.edu/10.3375/043.034.0408.

20. Question 20

Yes or No

Yes

Points

1

Confidence

Low

Answer / Justification

There is a lack of scientific studies that show the plant's propagules are frequently dispersed from regular contact with humans, which is why the confidence is low. However, the evidence suggests that Securigera varia can propagate from fragments of the above ground stem and this could be the mechanism behind why mowing is shown to be an ineffective method of control (Losure et al., 2009; Symstad, 2002).

Reference(s)

Losure, David A, Kirk A. Moloney, and Brian J Wilsey. 2009. “Modes of Crown Vetch Invasion and Persistence”. The American Midland Naturalist 161: 232-42. https://bioone-org.proxy.lib.pdx.edu/journals/the-american-midland-naturalist/volume-161/issue-2/0003-0031-161.2.232/Modes-of-Crown-Vetch-Invasion-and-Persistence/10.1674/0003-0031-161.2.232.full.

Symstad, Amy J. 2004. “Secondary Invasion Following the Reduction of Coronilla Varia (crownvetch) in Sand Prairie”. The American Midland Naturalist 152: 183-89. https://bioone-org.proxy.lib.pdx.edu/journals/the-american-midland-naturalist/volume-152/issue-1/0003-0031_2004_152_0183_SIFTRO_2.0.CO_2/Secondary-Invasion-Following-the-Reduction-of-Coronilla-varia-Crownvetch-in/10.1674/0003-0031(2004)152[0183:SIFTRO]2.0.

Total PRE Score

PRE Score

14

Questions Answered

20

Screener Confidence (%)

75

PRE Score Legend

The PRE Score is calculated by adding the point totals for each (answered) question.

< 13 : Low Potential Risk
13 - 15 : Moderate Potential Risk
> 15 : High Potential Risk

Questions Answered Legend

It is important to answer at least 16 questions to consider a PRE Score as "valid".

≥ 16 : Valid (80% or more questions answered)
≤ 15 : Invalid (not enough questions answered)

Evaluation Credits and Citation

Screener: Justine Casebolt

Below is a recommend citation when referencing this evaluation in other works:

Casebolt, Justine. "Securigera varia -- Oregon" Plant Risk Evaluator (PRE) published 2022-12-14 https://pretool.org/evaluations/1800

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Evaluation Reviewers

	Troy Abercrombie	reviewed on 2023-02-14
	Jutta Burger	reviewed on 2023-02-09
	Nicole Valentine	reviewed on 2023-01-27
	Alex Simmons	reviewed on 2022-12-29

Associated Project

2022 Western IPM Grant Project

"Expanding Continuity and Capacity in Invasive Plant Risk Assessments across Western States" is a continuation of the successful 2021 project titled "Building Continuity Across State Invasvie Plant Lists: Evaluating Invasive Risk of Horticultural Plants." Both 2021 and 2022's projects are funded by the Western Integrated Pest Management Center. Project partners for this year inclue the California Invasive Plant Council, PlantRight, The University of Arizona, Western Invasive Species Network, Pacific Northwest Invasive Species Council, the Yurok Tribe, and Nevada State Parks.

Associated Organizations, Agencies, and Institutions

Cascade Pacific Resource Conservation & Development

Portland State University