Crataegus gaylussacia
Klamath hawthorn
(c) Ryan McMinds, some rights reserved (CC BY) · licence
Family: Rosaceae · Type: Shrub · Native
Crataegus gaylussacia (Klamath hawthorn) is a native California shrub in the Rosaceae family, recognized by 20 stamens and shorter thorns are distinguishing features.
Klamath hawthorn is a native shrub found in the Klamath Ranges, northern Coast Ranges, Cascade Range, Sierra Nevada, and northern central Coast Counties in California, growing along streamsides in meadows, scrub, and forest at elevations of 30 to 1,250 meters. Flowering from May to June, this plant produces white flowers approximately 12 to 13 millimeters wide with pink anthers. Growing with distinctive thorns 8 to 12 millimeters long, the shrub develops branches with short-shoots bearing wide-elliptic to ovate leaves. Its leaves are 3 to 8 centimeters long with wedge-shaped bases, ranging from unlobed to shallowly lobed and varying from thin to somewhat leathery in texture. The fruit is a nearly spherical deep purple to black drupe about 10 to 12 millimeters in diameter, containing 3 to 5 stones.
Identification and appearance
Key characters: 3 sympatric species; 20 stamens and shorter thorns are distinguishing features
Habitat and range
Habitat: Streamsides in meadows, scrub, forest
Elevation: 30-1250 m
California counties: Sonoma, Marin, Siskiyou, Shasta, Humboldt, Trinity, Plumas, Del Norte
Outside California: to Alaska, Montana
Bloom period
Crataegus gaylussacia blooms May-Jun.
How to tell it apart
vs Ribes: Ribes lacks thorns and has maple-scented leaves; Crataegus has sharp thorns and unscented foliage.; vs Pyracantha: Pyracantha has narrow, unlobed evergreen leaves; Crataegus has broad, deeply lobed leaves that drop in fall.; vs Quercus: Quercus lacks thorns and has acorns; Crataegus has sharp thorns and small apple-like fruits.; vs Prunus: Prunus has smooth-edged or finely toothed leaves; Crataegus has prominently lobed leaves beyond the middle.; vs Pyrus: Pyrus has unlobed oval leaves and pear-shaped fruits; Crataegus has deeply lobed leaves and small round fruits.
Frequently asked questions
Is Crataegus gaylussacia native to California?
Yes. Crataegus gaylussacia is native to California (recorded as native).
When does Crataegus gaylussacia bloom?
Crataegus gaylussacia blooms May-Jun.
Where in California does Crataegus gaylussacia grow?
Crataegus gaylussacia occurs in Sonoma, Marin, Siskiyou, Shasta, Humboldt, Trinity, Plumas, Del Norte, at elevations of 30-1250 m.
What plant family does Crataegus gaylussacia belong to?
Crataegus gaylussacia is in the Rosaceae family, genus Crataegus.
What habitat does Crataegus gaylussacia grow in?
Crataegus gaylussacia grows in Streamsides in meadows, scrub, forest.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-06
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.