Taxon Report

Allium sanbornii A.W. Wood var. congdonii Jeps.

Congdon's onion

Print Report

Taxon Summary

Allium sanbornii var. congdonii, commonly known as Congdon's onion, is a perennial bulbiferous herb in the Alliaceae that is found only in California. It occurs within Chaparral, and Cismontane woodland, growing at elevations from 300 to 1395 meters. Allium sanbornii var. congdonii is ranked 4.3, Plants of Limited Distribution, A Watch List; Not very threatened in California.

Classification


Scientific Name:	Allium sanbornii A.W. Wood var. congdonii Jeps.
Common Name:	Congdon's onion
Family:	Alliaceae
Element Code:	PMLIL02211
USDA Plants Symbol:	ALSAC
Synonyms/Other Names:

Ecology and Life History


Lifeform:	perennial bulbiferous herb
Blooming Period: Apr-Jul	Apr-Jul
Elevation:	300-1395 (985-4575)
General Habitats:	Chaparral, Cismontane woodland
Microhabitat:	Serpentine, Volcanic
Microhabitat Details:	Ultramafic barrens or volcanic soils with scattered gray pines.

Conservation Status


CA Rare Plant Rank:	4.3
Global Rank:	G3T3
State Rank:	S3
State List:	None
Fed List:	None
Other Status:
CRPR Changes:

Occurrence Data from the CNDDB


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

Location


California Endemic: True
California Counties and Islands: Name (Code)
El Dorado (ELD), Mariposa (MPA), Nevada (NEV), Placer (PLA), Tuolumne (TUO)
Quads: Name (Quad Code)
Bear Valley (3712051), Colfax (3912018), Coulterville (3712062), Duncan Peak (3912025), Dutch Flat (3912027), Foresthill (3912017), Garden Valley (3812077), Georgetown (3812087), Greek Store (3912015), Groveland (3712072), Moccasin (3712073), Sonora (3712084), Tunnel Hill (3812086), Washington (3912037)

Threat List Data from the CNDDB


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

Notes



Possibly threatened by non-native plants and vehicles. See Flora of California 1(6):275 (1922) by W.L. Jepson for original description, and Madroño 36(2):122-130 (1989) for taxonomic treatment.
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 10 July 2025].