Eriogonum sphaerocephalum
Rock buckwheat
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Family: Polygonaceae · Type: Shrub · Native
Eriogonum sphaerocephalum (Rock buckwheat) is a native California shrub in the Polygonaceae family.
Rock buckwheat is a California native shrub found in rocky, open habitats at elevations of 500 to 1,400 meters. Flowering from June to August, this plant produces cream to bright yellow flowers in compact, head-like clusters approximately 1 to 5 centimeters wide. Growing as a low, spreading subshrub 20 to 40 centimeters tall with a width of 30 to 50 centimeters, it forms a dense, rounded shape with thin branches. Its basal leaves are small, 1 to 3 centimeters long, with gray-green surfaces covered in fine, woolly hairs that often curl slightly at the edges. The fruit is a small, nearly smooth seed 3 to 4 millimeters long with a slightly hairy tip.
Identification and appearance
Key characters: Geographically isolated, no sympatric species
Habitat and range
California counties: Siskiyou, Trinity, Modoc, Lassen, Tehama, Plumas, Shasta
How to tell it apart
vs Adenostoma: Eriogonum has flowers in cup-like involucres; Adenostoma has tiny white rose-family flowers in spikes.; vs Salvia: Eriogonum has six similar perianth parts; Salvia has two-lipped tubular flowers.; vs Fagopyrum: Eriogonum has flowers in involucred clusters; Fagopyrum has loose branching sprays without involucres.; vs Artemisia: Eriogonum has cup-surrounded flower clusters; Artemisia has tiny inconspicuous heads in drooping sprays.; vs Chorizanthe: Eriogonum has multiple flowers per involucre; Chorizanthe has one flower per involucre with spiny teeth.
Frequently asked questions
Is Eriogonum sphaerocephalum native to California?
Yes. Eriogonum sphaerocephalum is native to California (recorded as native).
Where in California does Eriogonum sphaerocephalum grow?
Eriogonum sphaerocephalum occurs in Siskiyou, Trinity, Modoc, Lassen, Tehama, Plumas, Shasta.
What plant family does Eriogonum sphaerocephalum belong to?
Eriogonum sphaerocephalum is in the Polygonaceae family, genus Eriogonum.
Related species
Other California species in the same genus, family, or bioregion.
- Eriogonum sphaerocephalum var. halimioides — Halimium wild buckwheat
- Eriogonum sphaerocephalum var. sphaerocephalum — Rock wild buckwheat
- Eriogonum strictum — Blue mountain buckwheat
- Eriogonum strictum var. anserinum — Goose lake wild buckwheat
- Eriogonum strictum var. greenei — Greene's buckwheat
- Eriogonum strictum var. proliferum — Proliferous wild buckwheat
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.