Allium cratericola
Cascade onion
(c) Don Loarie, some rights reserved (CC BY) · licence
Family: Alliaceae · Type: Herb · Native
Allium cratericola (Cascade onion) is a native California herb in the Alliaceae family, recognized by small stature and leaf-to-stem ratio.
Cascade onion is a California native perennial found in the Klamath Ranges, northern Coast Ranges, northern and central Sierra Nevada Foothills, southern Sierra Nevada, Tehachapi Mountains, southeastern San Francisco Bay Area, south Coast Ranges, Transverse Ranges, and San Jacinto Mountains in open serpentine, volcanic, or granitic places at elevations of 300 to 1,800 meters. Flowering from March to June, this plant produces delicate pink flowers in clusters of 20 to 30 blooms with pedicels 5 to 18 millimeters long. Growing with slender stems 3 to 10 centimeters tall, it emerges from a small ovoid bulb with distinctive outer layers. Its one to two leaves are approximately 1.5 to 4 times the stem length, ranging from flat to widely channeled. The small bulb has square-shaped cells arranged in two to three rows at its base, contributing to the plant's unique morphology.
Identification and appearance
Key characters: 48 sympatric species - distinguished by small stature and leaf-to-stem ratio
Habitat and range
Habitat: Open, serpentine, volcanic, or granitic places
Elevation: 300-1800 m
California counties: Ventura, Riverside, Napa, Trinity, Butte, Kern, Tuolumne, San Benito, Siskiyou, Mariposa, Madera, Nevada, Mendocino, Lake, Glenn, Amador, Tehama, El Dorado, Calaveras, Shasta, Sierra, Humboldt, Colusa, Monterey
Bloom period
Allium cratericola blooms Mar-Jun.
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 cratericola native to California?
Yes. Allium cratericola is native to California (recorded as native).
When does Allium cratericola bloom?
Allium cratericola blooms Mar-Jun.
Where in California does Allium cratericola grow?
Allium cratericola occurs in Ventura, Riverside, Napa, Trinity, Butte, Kern, Tuolumne, San Benito and other counties, at elevations of 300-1800 m.
What plant family does Allium cratericola belong to?
Allium cratericola is in the Alliaceae family, genus Allium.
What habitat does Allium cratericola grow in?
Allium cratericola grows in Open, serpentine, volcanic, or granitic places.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
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.