Taxon Report

Astragalus pycnostachyus Gray var. lanosissimus (Rydb.) Munz & McBurn.

Ventura Marsh milk-vetch

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Species Description:
Astragalus pycnostachyus var. lanosissimus, commonly known as Ventura Marsh milk-vetch, is a perennial herb in the Fabaceae that is found only in California. It occurs within Coastal dunes, Coastal scrub, Marshes and swamps (edges, coastal salt, and brackish), growing at elevations from 1 to 35 meters. Astragalus pycnostachyus var. lanosissimus is ranked 1B.1, Plants Rare, Threatened or Endangered in California and Elsewhere; Seriously threatened in California.

  Classification

Scientific Name:
Astragalus pycnostachyus Gray var. lanosissimus (Rydb.) Munz & McBurn.
Common Name:
Ventura Marsh milk-vetch
Family: Fabaceae
Element Code: PDFAB0F7B1
USDA Plants Symbol: ASPYL
Synonyms/Other Names:

Ecology and Life History

Lifeform: perennial herb
Blooming Period: (Jun)Aug-Oct (Jun)Aug-Oct
Elevation: 1-35 (5-115)
General Habitats: Coastal dunes, Coastal scrub, Marshes and swamps
Microhabitat:
Microhabitat Details:

Occurrence Data from the CNDDB

Total Occurrences: 7
Element Occurrence Ranks:
   Excellent (A) 0
   Good (B) 0
   Fair (C) 0
   Poor (D) 1
   None (X) 6
   Unknown (U) 0
California Endemic:  True
California Counties and Islands: Name (Code)
Los Angeles (LAX)*, Orange (ORA)*, Ventura (VEN)
Quads: Name (Quad Code)
Beverly Hills (3411814), Oxnard (3411922), Pitas Point (3411934), Saticoy (3411932), Seal Beach (3311861)*, Topanga (3411815)*, Venice (3311884)*, Ventura (3411933)*

Threat List Data from the CNDDB

Threat List Total: 6
EOs with Threat Listed: Total EOs % of EOs
1 14 %
Development 1 14%
Foot traffic/trampling 1 14%
Non-native plant impacts 1 14%
Other 1 14%
Over-collecting/poaching 1 14%
Pollution 1 14%

Notes

Rediscovered near Oxnard in 1997; now known from only one natural occurrence composed of 30-50 reproductive plants. Experimental reintroduction work underway as of 2003. Threatened by development, herbivory, cucumber mosaic virus, non-native plants, and hydrological alterations. See North American Flora 24:357-358 (1929) for original description, and Memoirs of the New York Botanical Garden 13:813 (1964) for taxonomic treatment.
Threats:
Taxonomy:

Selected References

Ventura Marsh Milk-Vetch (Astragalus pycnostachyus var. lanosissimus) Recovery Plan (USFWS 2023)
Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 12 January 2025].