Astragalus anxius is a rare species of milkvetch known by the common names troubled milkvetch and Ash Valley milkvetch. It is endemic to northern Lassen County, California, where it is critically imperiled.[1] It was formally described in 1992.[3]
| Astragalus anxius | |
|---|---|
Scientific classification 
| |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Rosids |
| Order: | Fabales |
| Family: | Fabaceae |
| Subfamily: | Faboideae |
| Genus: | Astragalus |
| Species: | A. anxius
|
| Binomial name | |
| Astragalus anxius Meinke & Kaye
| |
| Synonyms[2] | |
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Description
editAstragalus anxius is a perennial herb forming a matted patch of slender, delicate stems no longer than 20 centimeters. It is coated thinly in wavy hairs. The leaves are a few centimeters long and made up of several leaflets. The inflorescence contains 7 to 15 pealike flowers. Each flower is bicolored, the lower petals usually white and the upper banner petals purple to purple-veined white. The fruit is a hairy, oval-shaped legume pod up to half a centimeter long which dries to a papery texture.[4]
Taxonomy
editAstragalus anxius was first described in 1992, when it was separated from Astragalus tegetarioides.[3] Some sources treat it as a variety of A. tegetarioides, A. tegetarioides var. anxius.[2]
Distribution
editAstragalus anxius is endemic to northern Lassen County, California, where it grows in the volcanic soil of the Modoc Plateau.[3] There are 97 observations as of 2019 reported to Calflora.org, some of which are threatened by livestock trampling.[1]
References
edit- ^ a b c The Nature Conservancy
- ^ a b "Astragalus tegetarioides var. anxius (Meinke & Kaye) S.L.Welsh", Plants of the World Online, Royal Botanic Gardens, Kew, retrieved 2023-04-06
- ^ a b c Meinke, Robert J.; Kaye, Thomas N. (1992). "Taxonomic assessment of Astragalus tegetarioides (Fabaceae) and a new related species from northern California". Madroño. 39 (3): 193–204. JSTOR 41424908.
- ^ Park, Hyun-Jung; Kim, Hyun Young; Yoon, Kun-Ho; Kim, Kyung Soo; Shim, Insop (2009). "The Effects of Astragalus Membranaceus on Repeated Restraint Stress-induced Biochemical and Behavioral Responses". The Korean Journal of Physiology & Pharmacology. 13 (4): 315–319. doi:10.4196/kjpp.2009.13.4.315. PMC 2766712. PMID 19885016.