Taxon Report

Triphysaria floribunda (Benth.) Chuang & Heckard

San Francisco owl's-clover

Print Report

Taxon Summary

Triphysaria floribunda, commonly known as San Francisco owl's-clover, is a annual herb in the Orobanchaceae that is found only in California. It occurs within Coastal prairie, Coastal scrub, and Valley and foothill grassland, growing at elevations from 10 to 160 meters. Triphysaria floribunda is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

Classification


Scientific Name:	Triphysaria floribunda (Benth.) Chuang & Heckard
Common Name:	San Francisco owl's-clover
Family:	Orobanchaceae
Element Code:	PDSCR2T010
USDA Plants Symbol:	TRFL14
Synonyms/Other Names:	Orthocarpus floribundus Benth.

Ecology and Life History


Lifeform:	annual herb
Blooming Period: Apr-Jun	Apr-Jun
Elevation:	10-160 (35-525)
General Habitats:	Coastal prairie, Coastal scrub, Valley and foothill grassland
Microhabitat:	Serpentine (usually)
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.2
Global Rank:	G2?
State Rank:	S2?
State List:	None
Fed List:	None
Other Status:
CRPR Changes:

Occurrence Data from the CNDDB


Total Occurrences:	50
Element Occurrence Ranks:
Excellent (A)	2
Good (B)	16
Fair (C)	5
Poor (D)	4
None (X)	6
Unknown (U)	17

Location


California Endemic: True
California Counties and Islands: Name (Code)
Marin (MRN), San Francisco (SFO), San Mateo (SMT)
Quads: Name (Quad Code)
Drakes Bay (3812218), Hunters Point (3712263), Inverness (3812217), Montara Mountain (3712254), San Francisco North (3712274), San Francisco South (3712264), San Mateo (3712253), Tomales (3812228), Valley Ford (3812238)

Threat List Data from the CNDDB


Threat List Total:	9
EOs with Threat Listed:	Total EOs	% of EOs
	32	64 %
Grazing	22	44%
Non-native plant impacts	8	16%
Foot traffic/trampling	6	12%
Other	5	10%
Road/trail construction/maint.	3	6%
Development	3	6%
Erosion/runoff	1	2%
Insufficient population/stand size	1	2%
Mining	1	2%

Notes



Threatened by grazing, non-native plants, and trampling. See Systematic Botany 16(4):644-666 (1991) 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 11 November 2025].