Taxon Report
Allium jepsonii (Traub) Denison & D. McNealJepson's onion |
 © 2019 Steven Perry |
Taxon Summary
Allium jepsonii, commonly known as Jepson's onion, is a perennial bulbiferous herb in the Alliaceae that is found only in California. It occurs within Chaparral, Cismontane woodland, and Lower montane coniferous forest, growing at elevations from 300 to 1320 meters. Allium jepsonii is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.Classification
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Scientific Name: |
Allium jepsonii (Traub) Denison & D. McNeal |
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Common Name: |
Jepson's onion |
| Family: | Alliaceae |
| Element Code: | PMLIL022V0 |
| USDA Plants Symbol: | ALJE |
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Synonyms/Other Names: |
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Ecology and Life History
| Lifeform: | perennial bulbiferous herb |
| Blooming Period: Apr-Aug | Apr-Aug |
| Elevation: | 300-1320 (985-4330) |
| General Habitats: | Chaparral, Cismontane woodland, Lower montane coniferous forest |
| Microhabitat: | Serpentine, Volcanic |
| Microhabitat Details: |
Conservation Status
| CA Rare Plant Rank: | 1B.2 |
| Global Rank: | G2 |
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State Rank: |
S2 |
| State List: | None |
| Fed List: | None |
| Other Status: | BLM_S; SB_UCSC; USFS_S |
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CRPR Changes: |
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Occurrence Data from the CNDDB
| Total Occurrences: | 25 |
| Element Occurrence Ranks: | |
| Excellent (A) | 1 |
| Good (B) | 14 |
| Fair (C) | 3 |
| Poor (D) | 0 |
| None (X) | 0 |
| Unknown (U) | 7 |
| California Endemic: True | |
| California Counties and Islands: Name (Code) | |
| Butte (BUT), El Dorado (ELD), Placer (PLA), Tuolumne (TUO) | |
| Quads: Name (Quad Code) | |
| Auburn (3812181), Berry Creek (3912164), Cherokee (3912165), Paradise East (3912175), Pulga (3912174), Shingle Springs (3812068), Sonora (3712084), Stirling City (3912185) | |
Threat List Data from the CNDDB
| Threat List Total: | 10 | |
| EOs with Threat Listed: | Total EOs | % of EOs |
| 18 | 72 % | |
| Road/trail construction/maint. | 10 | 40% |
| Logging | 9 | 36% |
| Other | 3 | 12% |
| Recreational use (non-ORV) | 2 | 8% |
| Non-native plant impacts | 2 | 8% |
| Erosion/runoff | 2 | 8% |
| Grazing | 2 | 8% |
| Mining | 1 | 4% |
| Development | 1 | 4% |
| Vandalism/dumping/litter | 1 | 4% |
Citation
California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 4 November 2025].