Taxon Report

Phacelia ciliata Benth. var. opaca J.T. Howell

Merced phacelia

Print Report

Taxon Summary

Phacelia ciliata var. opaca, commonly known as Merced phacelia, is a annual herb in the Hydrophyllaceae that is found only in California. It occurs within Valley and foothill grassland, growing at elevations from 60 to 150 meters. Phacelia ciliata var. opaca is ranked 3.2, Plants About Which We Need More Information, A Review List; Moderately threatened in California.

Classification


Scientific Name:	Phacelia ciliata Benth. var. opaca J.T. Howell
Common Name:	Merced phacelia
Family:	Hydrophyllaceae
Element Code:	PDHYD0C0S2
USDA Plants Symbol:	PHCIO
Synonyms/Other Names:

Ecology and Life History


Lifeform:	annual herb
Blooming Period: Feb-May	Feb-May
Elevation:	60-150 (195-490)
General Habitats:	Valley and foothill grassland
Microhabitat:	Alkaline (sometimes)
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	3.2
Global Rank:	G5TH
State Rank:	SH
State List:	None
Fed List:	None
Other Status:
CRPR Changes:	changed from 1B.2 to 3.2 on 2013-02-01 changed from 1B.3 to 1B.2 on 2007-02-12

Occurrence Data from the CNDDB


Total Occurrences:	7
Element Occurrence Ranks:
Excellent (A)	0
Good (B)	0
Fair (C)	0
Poor (D)	0
None (X)	1
Unknown (U)	6

Location


California Endemic: True
California Counties and Islands: Name (Code)
Kings (KNG), Merced (MER)
Quads: Name (Quad Code)
Hacienda Ranch (3511975), Le Grand (3712022), Merced (3712034), Owens Reservoir (3712032), Plainsburg (3712023), Planada (3712033)

Threat List Data from the CNDDB


Threat List Total:	1
EOs with Threat Listed:	Total EOs	% of EOs
	2	29 %
Agriculture	2	28%

Notes



Previously on List 1B.2. Taxonomic distinctiveness from P. ciliata is uncertain; needs further study. Most occurrences historical; need field surveys. See P. ciliata in TJM (1993) and TJM 2. See Leaflets of Western Botany 1:221 (1936) for original description.
Threats:

Taxonomy:

Selected References

CRPR List Deletion on 2013-02-01

Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 29 October 2025].