CNPS Inventory Plant Detail

Hemizonia congesta ssp. congesta

Common Name:	white seaside tarplant
Family:	Asteraceae
Synonyms:	Hemizonia congesta, Hemizonia congesta ssp. leucocephala
Element Code:	PDAST4R065
Full Name:	Hemizonia congesta DC. ssp. congesta
USDA PLANTS Symbol:	HECOC2

Biology
Lifeform: annual herb Blooming Period: April - November Habitat: sometimes roadsides. • Valley and foothill grassland

Rarity Status
Rare Plant Rank: 1B.2 Rare, threatened, or endangered in California and elsewhere .2: Fairly endangered in California Federal Listing Status: Not Listed State Listing Status: Not Listed State Rank: S2S3 S2: Imperiled. S3: Vulnerable. Global Rank: G5T2T3 T2: Imperiled. T3: Vulnerable. G5: (species) Secure, considering populations outside California.

Occurrence Data from DFG
California Natural Diversity Database

Total # of Known Element Occurrences: 33
Element Occurrence Ranks:

A B C D X U

0 3 2 1 4 23

Population Status:

Historic >20 yrs	Recent <=20 yrs
25	8

Presence:

Present Extant	Possibly Extirpated	Extirpated
29	3	1

Notes

Threatened by agriculture, development, and road construction. Possibly threatened by grazing. Hybridizes with H. congesta ssp. lutescens. See H. congesta ssp. leucocephala in The Jepson Manual (1993). What was once considered H. congesta ssp. congesta in The Jepson Manual (1993) is now considered H. congesta ssp. lutescens; a common taxon.
To submit rare plant observation data, use the CNDDB field survey form. Please see also the CNPS Rare Plant Data page.
Date Added: 1988-01-01
Last Update: 2011-10-31

Location

Elevation: 20 - 560 meters

California Endemic: yes

States: California

California Counties and Islands: name (code)
Mendocino (MEN), Marin (MRN), San Francisco (SFO), San Mateo (SMT), Sonoma (SON)

Quads: name (DWR code) USGS code
San Francisco South (448B) 37122F4, San Francisco North (466C) 37122G4, San Rafael (467A) 37122H5, Bolinas (467B) 37122H6, Sears Point (483B) 38122B4, Petaluma (484B) 38122B6, San Geronimo (484C) 38122A6, Novato (484D) 38122A5, Point Reyes NE (485A) 38122B7, Tomales (485B) 38122B8, Inverness (485D) 38122A7, Sonoma (500C) 38122C4, Santa Rosa (501B) 38122D6, Cotati (501C) 38122C6, Sebastopol (502A) 38122D7, Valley Ford (502C) 38122C8, Two Rock (502D) 38122C7, Duncans Mills (503A) 38123D1, Arched Rock (503B) 38123D2, Jimtown (518A) 38122F7, Healdsburg (518D) 38122E7, Warm Springs Dam (519A) 38123F1, Willits (567A) 39123D3, Laughlin Range (567D) 39123C3, Noyo Hill (568B) 39123D6

Notes:

Definitions of codes preceding a county and/or quad:
*		Presumed extirpated
?		Uncertain about distribution or identity
?*		Uncertain about distribution, but presumed extirpated if once present
(?)		Occurrence confirmed, but possibly extirpated

Species may be present in other areas where conditions are favorable.

Presumed Extant

Presumed Extirpated or Unknown

147

Links to Leading Resources of Taxon Information
USDA PLANTS Calflora Consortium of California Herbaria CalPhotos California Department of Fish and Wildlife: CNDDB Quick Viewer

Suggested Citation
California Native Plant Society (CNPS). Inventory of Rare and Endangered Plants (online edition, v8-02). California Native Plant Society. Sacramento, CA. http://www.rareplants.cnps.org. Accessed .

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