Taxon Report

Hemizonia congesta DC. ssp. calyculata Babc. & Hall

Mendocino tarplant

Print Report

Taxon Summary

Hemizonia congesta ssp. calyculata, commonly known as Mendocino tarplant, is a annual herb in the Asteraceae that is found only in California. It occurs within Cismontane woodland, and Valley and foothill grassland, growing at elevations from 225 to 1400 meters. Hemizonia congesta ssp. calyculata is ranked 4.3, Plants of Limited Distribution, A Watch List; Not very threatened in California.

Classification


Scientific Name:	Hemizonia congesta DC. ssp. calyculata Babc. & Hall
Common Name:	Mendocino tarplant
Family:	Asteraceae
Element Code:	PDAST4R063
USDA Plants Symbol:	HECOC5
Synonyms/Other Names:	Hemizonia calyculata (Babc. & Hall) Keck

Ecology and Life History


Lifeform:	annual herb
Blooming Period: Jul-Nov	Jul-Nov
Elevation:	225-1400 (740-4595)
General Habitats:	Cismontane woodland, Valley and foothill grassland
Microhabitat:	Serpentine (sometimes)
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	4.3
Global Rank:	G5T4
State Rank:	S4
State List:	None
Fed List:	None
Other Status:
CRPR Changes:

Occurrence Data from the CNDDB


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

Location


California Endemic: True
California Counties and Islands: Name (Code)
Lake (LAK), Mendocino (MEN), Sutter (SUT), Tehama (TEH)
Quads: Name (Quad Code)
Bartlett Mtn. (3912227), Clearlake Highlands (3812286), Clearlake Oaks (3912216), Cow Mountain (3912321), Elk Mountain (3912238), Gerber (4012212), Greenough Ridge (3912334), Laughlin Range (3912333), Longvale (3912354), Newhouse Ridge (3912371), Orrs Springs (3912323), Sutter Buttes (3912127), Ukiah (3912322), Upper Lake (3912228), Willis Ridge (3912353), Willits (3912343)

Threat List Data from the CNDDB


Threat List Total:	0
EOs with Threat Listed:	Total EOs	% of EOs
	0	0 %

Notes




Threats:

Taxonomy:

Selected References

Hemizonia congesta ssp. calyculata profile for potential Species of Conservation Concern evaluation (2022)

USFS Potential Species of Conservation Concern Profile

Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 27 January 2025].