Taxon Report

Lessingia micradenia Greene var. micradenia

Tamalpais lessingia

Print Report

Taxon Summary

Lessingia micradenia var. micradenia, commonly known as Tamalpais lessingia, is a annual herb in the Asteraceae that is found only in California. It occurs within Chaparral, and Valley and foothill grassland, growing at elevations from 100 to 500 meters. Lessingia micradenia var. micradenia is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

Classification


Scientific Name:	Lessingia micradenia Greene var. micradenia
Common Name:	Tamalpais lessingia
Family:	Asteraceae
Element Code:	PDAST5S063
USDA Plants Symbol:	LEMIM
Synonyms/Other Names:

Ecology and Life History


Lifeform:	annual herb
Blooming Period: (Jun)Jul-Oct	(Jun)Jul-Oct
Elevation:	100-500 (330-1640)
General Habitats:	Chaparral, Valley and foothill grassland
Microhabitat:	Roadsides (often), Serpentine (usually)
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.2
Global Rank:	G2T2
State Rank:	S2
State List:	None
Fed List:	None
Other Status:	SB_CalBG/RSABG; SB_USDA
CRPR Changes:

Occurrence Data from the CNDDB


Total Occurrences:	9
Element Occurrence Ranks:
Excellent (A)	0
Good (B)	1
Fair (C)	0
Poor (D)	0
None (X)	0
Unknown (U)	8

Location


California Endemic: True
California Counties and Islands: Name (Code)
Marin (MRN)
Quads: Name (Quad Code)
Bolinas (3712286), Novato (3812215), San Geronimo (3812216), San Rafael (3712285)

Threat List Data from the CNDDB


Threat List Total:	4
EOs with Threat Listed:	Total EOs	% of EOs
	1	11 %
Biocides	1	11%
Erosion/runoff	1	11%
Foot traffic/trampling	1	11%
Road/trail construction/maint.	1	11%

Notes



Known from only four occurrences in the Mt. Tamalpais area. See Leaflets of Botanical Observation and Criticism 2:28 (1910) for original description, and University of California Publications in Botany 16:39-40 (1929) for taxonomic treatment.
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 5 February 2025].