Taxon Report

Calochortus obispoensis Lemmon

San Luis mariposa-lily

Print Report

Taxon Summary

Calochortus obispoensis, commonly known as San Luis mariposa-lily, is a perennial bulbiferous herb in the Liliaceae that is found only in California. It occurs within Chaparral, Cismontane woodland, Coastal scrub, and Valley and foothill grassland, growing at elevations from 50 to 730 meters. Calochortus obispoensis is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

Classification


Scientific Name:	Calochortus obispoensis Lemmon
Common Name:	San Luis mariposa-lily
Family:	Liliaceae
Element Code:	PMLIL0D110
USDA Plants Symbol:	CAOB
Synonyms/Other Names:

Ecology and Life History


Lifeform:	perennial bulbiferous herb
Blooming Period: May-Jul	May-Jul
Elevation:	50-730 (165-2395)
General Habitats:	Chaparral, Cismontane woodland, Coastal scrub, Valley and foothill grassland
Microhabitat:	Serpentine (often)
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.2
Global Rank:	G2
State Rank:	S2
State List:	None
Fed List:	None
Other Status:	BLM_S; SB_CalBG/RSABG; SB_SBBG; USFS_S
CRPR Changes:

Occurrence Data from the CNDDB


Total Occurrences:	46
Element Occurrence Ranks:
Excellent (A)	4
Good (B)	20
Fair (C)	5
Poor (D)	0
None (X)	0
Unknown (U)	17

Location


California Endemic: True
California Counties and Islands: Name (Code)
San Luis Obispo (SLO)
Quads: Name (Quad Code)
Arroyo Grande NE (3512025), Atascadero (3512046), Lopez Mtn. (3512035), Morro Bay South (3512037), Pebblestone Shut-in (3512161), Pismo Beach (3512026), Port San Luis (3512027), San Luis Obispo (3512036)

Threat List Data from the CNDDB


Threat List Total:	14
EOs with Threat Listed:	Total EOs	% of EOs
	30	65 %
Grazing	13	28%
Foot traffic/trampling	12	26%
Non-native plant impacts	9	19%
Development	8	17%
Feral pigs	5	10%
Military operations	5	10%
Other	5	10%
Road/trail construction/maint.	5	10%
Improper burning regime	4	8%
Erosion/runoff	3	6%
Recreational use (non-ORV)	3	6%
Mining	2	4%
ORV activity	1	2%
Wood cutting or brush clearing	1	2%

Notes



See Journal of Ecology 75:977-995 (1987) for population biology.
Threats:
Threatened by grazing, development, pipeline construction, road construction, and recreational activities. Potentially threatened by vegetation/fuel management and mining.
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 29 October 2025].