Taxon Report

Euphorbia ocellata Durand & Hilg. ssp. rattanii (S. Watson) Oudejans

Stony Creek spurge

Print Report

Taxon Summary

Euphorbia ocellata ssp. rattanii, commonly known as Stony Creek spurge, is a annual herb in the Euphorbiaceae that is found only in California. It occurs within Chaparral, Riparian scrub (streambanks), Valley and foothill grassland (sandy, and rocky), growing at elevations from 65 to 800 meters. Euphorbia ocellata ssp. rattanii is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

Classification


Scientific Name:	Euphorbia ocellata Durand & Hilg. ssp. rattanii (S. Watson) Oudejans
Common Name:	Stony Creek spurge
Family:	Euphorbiaceae
Element Code:	PDEUP0D1P1
USDA Plants Symbol:
Synonyms/Other Names:	Chamaesyce ocellata (Dur. & Hilg.) Millsp. ssp. rattanii (Wats.) Koutnik

Ecology and Life History


Lifeform:	annual herb
Blooming Period: May-Oct	May-Oct
Elevation:	65-800 (215-2625)
General Habitats:	Chaparral, Riparian scrub, Valley and foothill grassland
Microhabitat:
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.2
Global Rank:	G4T2?
State Rank:	S2?
State List:	None
Fed List:	None
Other Status:	BLM_S
CRPR Changes:

Occurrence Data from the CNDDB


Total Occurrences:	39
Element Occurrence Ranks:
Excellent (A)	1
Good (B)	4
Fair (C)	0
Poor (D)	0
None (X)	0
Unknown (U)	34

Location


California Endemic: True
California Counties and Islands: Name (Code)
Glenn (GLE), Tehama (TEH)
Quads: Name (Quad Code)
Black Butte Dam (3912273), Chrome (3912265), Cold Fork (4012226), Corning (3912282), Elk Creek (3912255), Gerber (4012212), Hall Ridge (3912276), Henleyville (3912283), Inskip Hill (4012138), Kirkwood (3912272), Los Molinos (4012211), Lowrey (4012215), Newville (3912275), Paskenta (3912285), Raglin Ridge (4012216), Sehorn Creek (3912274), Stonyford (3912245)

Threat List Data from the CNDDB


Threat List Total:	8
EOs with Threat Listed:	Total EOs	% of EOs
	7	18 %
Foot traffic/trampling	4	10%
Grazing	4	10%
ORV activity	2	5%
Other	2	5%
Recreational use (non-ORV)	1	2%
Mining	1	2%
Altered flood/tidal/hydrologic regime	1	2%
Development	1	2%

Notes



Threatened by foot trampling, recreational activities, and vehicles. Can be confused with ssp. ocellata. See Proceedings of the American Academy of Arts and Sciences 20:372 (1885) for original description, Phytologia 67(1):47 (1989) for revised nomenclature, and Taxon 55:397-420 (2006) for taxonomic treatment.
Threats:

Taxonomy:

Selected References

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].