Taxon Report

Allium tuolumnense (Traub) Denison & D. McNeal

Rawhide Hill onion

Print Report

Taxon Summary

Allium tuolumnense, commonly known as Rawhide Hill onion, is a perennial bulbiferous herb in the Alliaceae that is found only in California. It occurs within Cismontane woodland, growing at elevations from 300 to 600 meters. Allium tuolumnense is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

Classification


Scientific Name:	Allium tuolumnense (Traub) Denison & D. McNeal
Common Name:	Rawhide Hill onion
Family:	Alliaceae
Element Code:	PMLIL022W0
USDA Plants Symbol:	ALTU
Synonyms/Other Names:	Allium sanbornii Wood var. tuolumnense Ownbey & Aase

Ecology and Life History


Lifeform:	perennial bulbiferous herb
Blooming Period: Mar-May	Mar-May
Elevation:	300-600 (985-1970)
General Habitats:	Cismontane woodland
Microhabitat:
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.2
Global Rank:	G2
State Rank:	S2
State List:	None
Fed List:	None
Other Status:	BLM_S
CRPR Changes:

Occurrence Data from the CNDDB


Total Occurrences:	25
Element Occurrence Ranks:
Excellent (A)	3
Good (B)	7
Fair (C)	1
Poor (D)	0
None (X)	0
Unknown (U)	14

Location


California Endemic: True
California Counties and Islands: Name (Code)
Mariposa (MPA), Tuolumne (TUO)
Quads: Name (Quad Code)
Chinese Camp (3712074), Coulterville (3712062), Hornitos (3712052), Keystone (3712075), Moccasin (3712073), New Melones Dam (3712085), Sonora (3712084)

Threat List Data from the CNDDB


Threat List Total:	12
EOs with Threat Listed:	Total EOs	% of EOs
	16	64 %
Grazing	6	24%
Mining	5	20%
Foot traffic/trampling	5	20%
Improper burning regime	4	16%
Altered flood/tidal/hydrologic regime	3	12%
Other	3	12%
Recreational use (non-ORV)	3	12%
Road/trail construction/maint.	3	12%
Development	2	8%
Erosion/runoff	2	8%
ORV activity	2	8%
Vandalism/dumping/litter	1	4%

Notes



Known from approximately twenty occurrences. Threatened by grazing, foot traffic, urbanization, road maintenance, and vehicles. See Plant Life 28:63 (1972) for original description, and Madroño 36(2):122-130 (1989) for revised nomenclature.
Threats:

Taxonomy:

Selected References

Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 12 February 2025].