Taxon Report

Hosackia yollabolliensis (Munz) D.D. Sokoloff

Yolla Bolly Mtns. bird's-foot trefoil

Print Report

2013 Shasta-Trinity National Forest

Taxon Summary

Hosackia yollabolliensis, commonly known as Yolla Bolly Mtns. bird's-foot trefoil, is a perennial herb in the Fabaceae that is found only in California. It occurs within Meadows and seeps, and Upper montane coniferous forest (openings), growing at elevations from 1645 to 2135 meters. Hosackia yollabolliensis is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

Classification


Scientific Name:	Hosackia yollabolliensis (Munz) D.D. Sokoloff
Common Name:	Yolla Bolly Mtns. bird's-foot trefoil
Family:	Fabaceae
Element Code:	PDFAB2A1F0
USDA Plants Symbol:
Synonyms/Other Names:	Lotus yollabolliensis

Ecology and Life History


Lifeform:	perennial herb
Blooming Period: Jun-Aug	Jun-Aug
Elevation:	1645-2135 (5395-7005)
General Habitats:	Meadows and seeps, Upper montane coniferous forest
Microhabitat:	Dry, Gravelly (often), Slopes
Microhabitat Details:	dry barren exposed slopes

Conservation Status


CA Rare Plant Rank:	1B.2
Global Rank:	G2
State Rank:	S2
State List:	None
Fed List:	None
Other Status:	SB_CalBG/RSABG
CRPR Changes:	changed from 4.3 to 1B.2 on 2013-08-21

Occurrence Data from the CNDDB


Total Occurrences:	11
Element Occurrence Ranks:
Excellent (A)	0
Good (B)	0
Fair (C)	0
Poor (D)	0
None (X)	0
Unknown (U)	11

Location


California Endemic: True
California Counties and Islands: Name (Code)
Humboldt (HUM), Trinity (TRI)
Quads: Name (Quad Code)
Black Rock Mtn. (4012321), Blake Mountain (4012355), Dinsmore (4012345), Forest Glen (4012333), Hyampom (4012354), North Yolla Bolly (4012228), Sims Mountain (4012365), Sportshaven (4012344)

Threat List Data from the CNDDB


Threat List Total:	2
EOs with Threat Listed:	Total EOs	% of EOs
	2	18 %
Other	2	18%
ORV activity	1	9%

Notes



Previously CRPR 4.3; rarer than originally thought.
Threats:
Threatened by vehicles, conifer encrouchment, and non-native plants. Potentially threatened by climate shifts. Possibly threatened by trampling and grazing.
Taxonomy:

Selected References

Proposed Change from California Rare Plant Rank 4.3, G3 / S3.3 to 1B.2, G2 / S2

Aliso 3:117 (1955)

Kew Bulletin 55(4):1010 (2000)

Hosackia yollabolliensis profile for potential Species of Conservation Concern evaluation (2022)

Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 15 November 2025].