Taxon Report

Monolopia congdonii (Gray) B.G. Baldwin

San Joaquin woollythreads

Print Report

Taxon Summary

Monolopia congdonii, commonly known as San Joaquin woollythreads, is a annual herb in the Asteraceae that is found only in California. It occurs within Chenopod scrub, and Valley and foothill grassland (sandy), growing at elevations from 60 to 800 meters. Monolopia congdonii is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

Classification


Scientific Name:	Monolopia congdonii (Gray) B.G. Baldwin
Common Name:	San Joaquin woollythreads
Family:	Asteraceae
Element Code:	PDASTA8010
USDA Plants Symbol:	MOCO7
Synonyms/Other Names:	Lembertia congdonii (Gray) Greene Eatonella congdonii

Ecology and Life History


Lifeform:	annual herb
Blooming Period: Feb-May	Feb-May
Elevation:	60-800 (195-2625)
General Habitats:	Chenopod scrub, Valley and foothill grassland
Microhabitat:
Microhabitat Details:

Conservation Status


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

Occurrence Data from the CNDDB


Total Occurrences:	111
Element Occurrence Ranks:
Excellent (A)	8
Good (B)	41
Fair (C)	14
Poor (D)	5
None (X)	24
Unknown (U)	19

Location


California Endemic: True
California Counties and Islands: Name (Code)
Fresno (FRE), Kern (KRN), Kings (KNG), San Benito (SBT), San Luis Obispo (SLO), Santa Barbara (SBA), Tulare (TUL)*
Quads: Name (Quad Code)
Alpaugh (3511984), Arvin (3511827), Avenal (3612012), Avenal Gap (3511978), Belridge (3511946), Blackwells Corner (3511957), Caliente Mtn. (3511917), California Hot Springs (3511886), Cantua Creek (3612053), Carneros Rocks (3511947), Coalinga (3612023), Coit Ranch (3612064), Curry Mountain (3612014), Cuyama (3411985), Domengine Ranch (3612033), Ducor (3511981), Edison (3511837), Elkhorn Hills (3511915), Famoso (3511952), Fellows (3511925), Fountain Springs (3511888), Fox Mountain (3411975), Gibbon Peak (3511887), Guijarral Hills (3612022), Huron (3612021), Johnsondale (3511885), Kettleman City (3611918), Kettleman Plain (3512081), Kreyenhagen Hills (3612013), La Cima (3612011), Levis (3612054), Lillis Ranch (3612044), Lokern (3511945), Los Viejos (3511988), Lost Hills (3511956), Lost Hills NE (3511965), Lost Hills NW (3511966), Monocline Ridge (3612055), New Cuyama (3411986), Oil Center (3511848), Oildale (3511941), Painted Rock (3511927), Panoche (3612057), Panorama Hills (3511926), Pixley (3511983), Posey (3511876), Rio Bravo Ranch (3511847), Rosedale (3511942), Sausalito School (3511982), Semitropic (3511955), Simmler (3511938), Stevens (3511932), Success Dam (3611818), Taylor Canyon (3511918), Tranquillity (3612063), Tres Pecos Farms (3612043)*, Tumey Hills (3612056), Wells Ranch (3511916), West Camp (3511977), West Elk Hills (3511935)

Threat List Data from the CNDDB


Threat List Total:	12
EOs with Threat Listed:	Total EOs	% of EOs
	93	84 %
Grazing	54	48%
Agriculture	37	33%
Mining	26	23%
Development	16	14%
ORV activity	14	12%
Non-native plant impacts	11	9%
Road/trail construction/maint.	8	7%
Other	7	6%
Erosion/runoff	6	5%
Vandalism/dumping/litter	2	1%
Disking	2	1%
Altered flood/tidal/hydrologic regime	1	0%

Notes



Approximately half of historical occurrences extirpated. Need quad for TUL Co. Seriously threatened by agricultural conversion, energy development, urbanization, grazing, trampling, and vehicles. Federally-listed as Lembertia congdonii; see this name in The Jepson Manual. See Proceedings of the American Academy of Arts and Sciences 19:20 (1883) for original description, and Novon 9:460-461 (1999) 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 8 November 2025].