Taxon Report

Streptanthus brachiatus F.W. Hoffm. ssp. brachiatus

Socrates Mine jewelflower

Print Report

Taxon Summary

Streptanthus brachiatus ssp. brachiatus, commonly known as Socrates Mine jewelflower, is a perennial herb in the Brassicaceae that is found only in California. It occurs within Chaparral, and Closed-cone coniferous forest, growing at elevations from 545 to 1000 meters. Streptanthus brachiatus ssp. brachiatus is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

Classification


Scientific Name:	Streptanthus brachiatus F.W. Hoffm. ssp. brachiatus
Common Name:	Socrates Mine jewelflower
Family:	Brassicaceae
Element Code:	PDBRA2G072
USDA Plants Symbol:	STBRB
Synonyms/Other Names:

Ecology and Life History


Lifeform:	perennial herb
Blooming Period: May-Jun	May-Jun
Elevation:	545-1000 (1790-3280)
General Habitats:	Chaparral, Closed-cone coniferous forest
Microhabitat:	Serpentine (usually)
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.2
Global Rank:	G2T1
State Rank:	S1
State List:	None
Fed List:	None
Other Status:	BLM_S
CRPR Changes:

Occurrence Data from the CNDDB


Total Occurrences:	10
Element Occurrence Ranks:
Excellent (A)	1
Good (B)	3
Fair (C)	0
Poor (D)	0
None (X)	0
Unknown (U)	6

Location


California Endemic: True
California Counties and Islands: Name (Code)
Lake (LAK), Napa (NAP), Sonoma (SON)
Quads: Name (Quad Code)
Detert Reservoir (3812265), The Geysers (3812277), Whispering Pines (3812276)

Threat List Data from the CNDDB


Threat List Total:	4
EOs with Threat Listed:	Total EOs	% of EOs
	4	40 %
Mining	3	30%
Road/trail construction/maint.	2	20%
Development	1	10%
ORV activity	1	10%

Notes



Known from fewer than ten occurrences. Plants from LAK Co. (517B, 533C) are more appropriately assigned to S. brachiatus ssp. hoffmanii. Possibly threatened by alteration of fire regimes. See Madroño 36(1):36 (1989) for revised nomenclature.
Threats:

Taxonomy:

Selected References

Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 26 October 2025].