Taxon Report

Leptosiphon rosaceus (Greene) R. Battaglia

rose leptosiphon

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Taxon Summary

Leptosiphon rosaceus, commonly known as rose leptosiphon, is a annual herb in the Polemoniaceae that is found only in California. It occurs within Coastal bluff scrub, growing at elevations from 0 to 100 meters. Leptosiphon rosaceus is ranked 1B.1, Plants Rare, Threatened or Endangered in California and Elsewhere; Seriously threatened in California.

Classification


Scientific Name:	Leptosiphon rosaceus (Greene) R. Battaglia
Common Name:	rose leptosiphon
Family:	Polemoniaceae
Element Code:	PDPLM09180
USDA Plants Symbol:	LERO7
Synonyms/Other Names:	Linanthus rosaceus Greene

Ecology and Life History


Lifeform:	annual herb
Blooming Period: Apr-Jul	Apr-Jul
Elevation:	0-100 (0-330)
General Habitats:	Coastal bluff scrub
Microhabitat:
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.1
Global Rank:	G1
State Rank:	S1
State List:	None
Fed List:	None
Other Status:	SB_CalBG/RSABG
CRPR Changes:

Occurrence Data from the CNDDB


Total Occurrences:	31
Element Occurrence Ranks:
Excellent (A)	0
Good (B)	11
Fair (C)	7
Poor (D)	2
None (X)	6
Unknown (U)	5

Location


California Endemic: True
California Counties and Islands: Name (Code)
Marin (MRN), San Francisco (SFO), San Mateo (SMT), Sonoma (SON)
Quads: Name (Quad Code)
Drakes Bay (3812218), Half Moon Bay (3712244), Hunters Point (3712263), Montara Mountain (3712254), Oakland West (3712273), Pigeon Point (3712224), Plantation (3812353), Point Bonita (3712275), San Francisco North (3712274), San Francisco South (3712264), San Gregorio (3712234), Tomales (3812228), Valley Ford (3812238)*

Threat List Data from the CNDDB


Threat List Total:	5
EOs with Threat Listed:	Total EOs	% of EOs
	18	58 %
Grazing	12	38%
Non-native plant impacts	7	22%
Foot traffic/trampling	3	9%
Erosion/runoff	1	3%
Road/trail construction/maint.	1	3%

Notes



Possibly threatened by competition and non-native plants. Not in The Jepson Manual. See Curtis Bot. Mag. 96:tab. 5863 (1870) for original description, and Madroño 48(2):75 (2001) 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 22 November 2025].