Taxon Report

Lessingia arachnoidea Greene

Crystal Springs lessingia

Print Report

Species Description:
Lessingia arachnoidea, commonly known as Crystal Springs lessingia, is a annual herb in the Asteraceae that is found only in California. It occurs within Cismontane woodland, Coastal scrub, and Valley and foothill grassland, growing at elevations from 60 to 200 meters. Lessingia arachnoidea is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

Classification


Scientific Name:	Lessingia arachnoidea Greene
Common Name:	Crystal Springs lessingia
Family:	Asteraceae
Element Code:	PDAST5S0C0
USDA Plants Symbol:	LEAR33
Synonyms/Other Names:	Lessingia micradenia Greene var. arachnoidea (Greene) Ferris

Ecology and Life History


Lifeform:	annual herb
Blooming Period: Jul-Oct	Jul-Oct
Elevation:	60-200 (195-655)
General Habitats:	Cismontane woodland, Coastal scrub, Valley and foothill grassland
Microhabitat:	Roadsides (often), Serpentine
Microhabitat Details:

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:

Occurrence Data from the CNDDB


Total Occurrences:	11
Element Occurrence Ranks:
Excellent (A)	2
Good (B)	4
Fair (C)	2
Poor (D)	0
None (X)	0
Unknown (U)	3

Location


California Endemic: True
California Counties and Islands: Name (Code)
San Mateo (SMT), Sonoma (SON)
Quads: Name (Quad Code)
Camp Meeker (3812248), Duncans Mills (3812341), Montara Mountain (3712254), San Mateo (3712253), Woodside (3712243)

Threat List Data from the CNDDB


Threat List Total:	6
EOs with Threat Listed:	Total EOs	% of EOs
	9	82 %
Other	6	54%
Non-native plant impacts	5	45%
Road/trail construction/maint.	4	36%
Vandalism/dumping/litter	1	9%
Disking	1	9%
Recreational use (non-ORV)	1	9%

Notes



Known only from near Crystal Springs Reservoir (SMT Co.); occurrences from SON Co. (502B, 518C) need taxonomic verification. Threatened by non-native plants and pipeline maintenance. See Leaflets of Botanical Observation and Criticism 2:29 (1910) for original description.
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 20 January 2025].