Taxon Details

Allium howellii var. sanbenitense

San Benito onion

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Photo of Allium howellii var. sanbenitense

2017 Amelia Ryan/NPS

Taxon Summary:

Allium howellii var. sanbenitense, commonly known as San Benito onion, is a perennial bulbiferous herb in the Alliaceae that is found only in California. It occurs within Chaparral (openings), and Valley and foothill grassland, growing at elevations from 390 to 1365 meters. Allium howellii var. sanbenitense is ranked 1B.3, Plants Rare, Threatened or Endangered in California and Elsewhere; Not very threatened in California.

Classification

Scientific Name: Allium howellii Eastw. var. sanbenitense (Traub) McNeal & T.D. Jacobsen
Common Name: San Benito onion
Family:	Alliaceae
Element Code:	PMLIL02163
USDA Plants Symbol:	ALHOS
Synonyms/Other Names:
Name Status:	JEF, FNA, POWO, IPNI, Tropicos

Conservation Status

CA Rare Plant Rank:	1B.3
Fed List:	None
State List:	None
Global Rank:	G3G4T3
State Rank:	S3
Other Status:	BLM_S; SB_SBBG
CRPR Changes: added to 1B.3 on 2017-04-04
Add Date:	2017-04-04
Date Edited:	2023-05-02

Ecology and Life History

Lifeform: perennial bulbiferous herb

Blooming Period: Apr-May

Elevation:
390 - 1365 meters
1280 - 4480 feet

General Habitats:

Chaparral (openings)
Valley and foothill grassland

Microhabitat Details:

Microhabitat:

Clay
Slopes (often)

Notes

Notes: Possibly threatened by grazing and development. See Herbertia 12:68 (1945) for original description, and Plant Life 28:66 (1972) and Flora of North America 26:251 (2003) for revised nomenclature.
Threats:
Taxonomy:

Threat List Data from the CNDDB

THREAT LIST:
Threat List Total:	2
	Total EOs	% of EOs
EOs with Threat Listed:	1	6 %
Grazing	1	5%
ORV activity	1	5%

Occurrence Data from the CNDDB

Element Occurrence Ranks:
Total Occurrences:					18
A	B	C	D	X	U
0	2	0	0	0	16

Occurrence Status:
Historical >20 Years	6
Recent <=20 Years	12

Presence:
Presumed Extant	18
Possibly Extirpated	0
Presumed Extirpated	0

Location

California Endemic:

California Island:

States: Name (Code)
California (CA)

California Counties and Islands: Name (Code)
Fresno (FRE), Monterey (MNT), San Benito (SBT)

Quads: Name (Quad Code)
Ciervo Mtn. (3612045), Idria (3612046), Mercey Hot Springs (3612067), Panoche (3612057), Priest Valley (3612026), Tumey Hills (3612056)

Notes:

Definitions of codes following a county and/or quad:
*		Presumed extirpated
(?)		Occurrence confirmed, but possibly extirpated
Quad and county data is imported from the CNDDB. Species may be present in other areas where conditions are favorable. These data should NOT be substituted for pre-project review or for on-site surveys.

Regional Map

Map

Presumed Extant

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CNPS Rare Plant Inventory