Allium sanbornii var. congdonii
Congdon's onion, Congdon's onion, Congdon's onion
Photo: parent species Allium sanbornii · (c) Kyle Elshoff, some rights reserved (CC BY) · licence
Family: Alliaceae · Type: Herb · Native
Conservation status: CNPS 4.3
Allium sanbornii var. congdonii (Congdon's onion) is a native California herb in the Alliaceae family, recognized by features are serpentine habitat and jagged petal margins.
Congdon's onion is a California native perennial ranked 4.3 by CNPS, found in northern and central Sierra Nevada Foothills on serpentine outcrops at elevations of 300 to 700 meters. Flowering from June to July, this plant produces white to pale pink flowers with distinctively acuminate perianth parts that appear slightly jagged. Growing with slender stems typical of the onion family, it forms clusters of delicate flowers. Its leaves are linear and grass-like, emerging from a bulbous base characteristic of Allium species. The inner perianth parts are notably 1.5 times longer than the outer parts, with a clearly three-lobed stigma.
Identification and appearance
Key characters: Geographically isolated; diagnostic features are serpentine habitat and jagged petal margins
Habitat and range
Habitat: Serpentine outcrops
Elevation: 300-700 m
California counties: Mariposa, El Dorado, Nevada, Alpine, Tuolumne, Placer
Bloom period
Allium sanbornii var. congdonii blooms Jun-Jul.
Conservation status
CNPS 4.3
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 sanbornii var. congdonii native to California?
Yes. Allium sanbornii var. congdonii is native to California (recorded as native).
When does Allium sanbornii var. congdonii bloom?
Allium sanbornii var. congdonii blooms Jun-Jul.
Where in California does Allium sanbornii var. congdonii grow?
Allium sanbornii var. congdonii occurs in Mariposa, El Dorado, Nevada, Alpine, Tuolumne, Placer, at elevations of 300-700 m.
What plant family does Allium sanbornii var. congdonii belong to?
Allium sanbornii var. congdonii is in the Alliaceae family, genus Allium.
Is Allium sanbornii var. congdonii rare or endangered?
Allium sanbornii var. congdonii carries California Rare Plant Rank 4.3, state rank S3.
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.