Astragalus pycnostachyus var. lanosissimus
|Astragalus pycnostachyus var. lanosissimus|
|Variety:||A. p. var. lanosissimus|
|Astragalus pycnostachyus var. lanosissimus
(Rydb.) Munz & McBurney ex Munz
Astragalus pycnostachyus var. lanosissimus, the Ventura marsh milk-vetch is a short-lived, herbaceous perennial in the pea family Fabaceae, with dense clusters of small light yellow flowers. It has silvery white, pinnately compound leaves and flowers from June through October. The species was listed as endangered May 17, 2001 by the U.S. Fish and Wildlife Service 
Historically, Ventura marsh milk-vetch occurred in back dune habitat, coastal meadows and near coastal salt marshes from Ventura County to Orange County. Over the last century seven historical occurrences were known to exist. Ventura marsh milk-vetch was extirpated from these sites and was therefore thought to be extinct until it was rediscovered in June 1997 by a USFWS biologist at a proposed development site. It had only been seen twice in the last century.
Today, only this one population of Ventura marsh milk-vetch is known to exist near the City of Oxnard, Ventura County, California, all within a 2,854 square feet (265.1 m2) area (less than 0.6 of an acre). The population occurs on disturbed coastal backdunes on fill material at a closed oil-waste dump site. Since 1997 between 192 and 374 Ventura marsh milk-vetch individuals have been observed at the site. Most of these individuals are seedlings or small juveniles. Southern California coastal wetland habitats have declined by 80–90% and those remaining are frequently degraded. Very little is known about the ecological requirements of this species.
The only known population of Ventura marsh milk-vetch is threatened by predation and potential habitat modification and may be susceptible to alterations in its hydrologic regime and competition from non-native plant species.
The DFG is working closely with the landowner, the USFWS and other interested parties to identify areas that may be suitable for introducing Ventura marsh milk-vetch as part of recovery for the species. Greenhouse studies on this species are ongoing, as well as research to learn more about the ecological requirements of this species.