Taxon Report

Ancistrocarphus keilii Morefield

Santa Ynez groundstar

Print Report

Taxon Summary

Ancistrocarphus keilii, commonly known as Santa Ynez groundstar, is a annual herb in the Asteraceae that is found only in California. It occurs within Chaparral, and Cismontane woodland, growing at elevations from 40 to 130 meters. Ancistrocarphus keilii is ranked 1B.1, Plants Rare, Threatened or Endangered in California and Elsewhere; Seriously threatened in California.

Classification


Scientific Name:	Ancistrocarphus keilii Morefield
Common Name:	Santa Ynez groundstar
Family:	Asteraceae
Element Code:	PDASTD5020
USDA Plants Symbol:
Synonyms/Other Names:

Ecology and Life History


Lifeform:	annual herb
Blooming Period: Mar-Apr	Mar-Apr
Elevation:	40-130 (130-425)
General Habitats:	Chaparral, Cismontane woodland
Microhabitat:	Sandy
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.1
Global Rank:	G1
State Rank:	S1
State List:	None
Fed List:	None
Other Status:	BLM_S
CRPR Changes:	added to 1B on 2005-07-27

Occurrence Data from the CNDDB


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

Location


California Endemic: True
California Counties and Islands: Name (Code)
Santa Barbara (SBA)
Quads: Name (Quad Code)
Lompoc (3412064), Lompoc Hills (3412054), Los Alamos (3412063), Santa Rosa Hills (3412053), Surf (3412065)

Threat List Data from the CNDDB


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

Notes



Known only from the recent type locality and one ambiguous historical collection, all in the Santa Ynez River drainage.
Threats:

Taxonomy:
See Novon 14(4):464 (2004) for original description.

Selected References

Proposed Addition to CRPR 1B (2005)

Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 17 November 2025].