Allium jepsonii
Jepson's onion, Jepson's onion, Jepson's onion
U.S. BLM (via Wikimedia Commons) · CC0
Family: Alliaceae · Type: Herb · Native
Conservation status: CNPS 1B.2
Allium jepsonii (Jepson's onion) is a native California herb in the Alliaceae family, recognized by No sympatric species - geographically isolated.
Jepson's onion is a rare (CNPS 1B.2) California native perennial found in northern and central Sierra Nevada Foothills in Butte, El Dorado, Placer, and Tuolumne counties, growing on open serpentine or volcanic slopes at elevations of 300 to 600 meters. Flowering from May to July, this plant produces white flowers with deep pink midveins, arranged in clusters of 20 to 60 blossoms, each approximately 7 to 8.5 millimeters long with delicate jagged perianth parts. Growing with a single cylindric leaf equal to its 25 to 40 centimeters tall stem, it emerges from an ovoid bulb 15 to 25 millimeters in size. Its distinctive white flower petals have reflexed tips and are subtly marked by deep pink midveins, creating an elegant visual contrast. The plant's ovary features six obvious, slightly jagged crests, adding to its unique botanical character.
Identification and appearance
Key characters: No sympatric species - geographically isolated
Habitat and range
Habitat: Open, serpentine or volcanic slopes, flats
Elevation: 300-600 m
California counties: Tuolumne, Butte, Placer, El Dorado
Bloom period
Allium jepsonii blooms May-Jul.
Conservation status
CNPS 1B.2
How to tell it apart
vs Triteleia: Allium smells like onion when crushed; triplet lily has no smell.; vs Agapanthus: Allium smells like onion; lily-of-the-Nile has no smell and much larger flowers.; vs Dipterostemon: Allium smells like onion when crushed; ookow has no onion smell.; vs Nothoscordum: Allium smells like onion when crushed; false garlic has no smell.; vs Tulbaghia: Allium has flowers in tight umbels; society garlic has flowers in loose open clusters.
Frequently asked questions
Is Allium jepsonii native to California?
Yes. Allium jepsonii is native to California (recorded as native).
When does Allium jepsonii bloom?
Allium jepsonii blooms May-Jul.
Where in California does Allium jepsonii grow?
Allium jepsonii occurs in Tuolumne, Butte, Placer, El Dorado, at elevations of 300-600 m.
What plant family does Allium jepsonii belong to?
Allium jepsonii is in the Alliaceae family, genus Allium.
Is Allium jepsonii rare or endangered?
Allium jepsonii carries California Rare Plant Rank 1B.2, state rank S2.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CNPS Rare Plant Inventory · Index of California Plant Names · CalPhotos · CDFW CNDDB
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.