Eriogonum congdonii
Congdon's buckwheat
(c) Matt Berger, some rights reserved (CC BY), uploaded by Matt Berger · licence
Family: Polygonaceae · Type: Shrub · Native
Conservation status: CNPS 4.3
Eriogonum congdonii (Congdon's buckwheat) is a native California shrub in the Polygonaceae family, recognized by subshrub habit and yellow flowers in large involucres.
Congdon's buckwheat is a rare California native shrub ranked 4.3 by CNPS, found in the Klamath Ranges in serpentine habitats at elevations of 1,500 to 2,300 meters. Flowering from July to September, this plant produces yellow flowers in compact clusters with distinctive involucres 5 to 6 millimeters long. Growing as a low subshrub 15 to 50 centimeters tall with a spread of 10 to 30 centimeters, it has generally glabrous stems and a compact growth form. Its basal leaves are small, 5 to 20 millimeters long and 3 to 6 millimeters wide, with a dense white tomentose underside and smooth upper surface. The fruit is 4 to 5.5 millimeters long, with a notably hairy beak contrasting with its otherwise smooth surface.
Identification and appearance
Key characters: 45 sympatric species; subshrub habit and yellow flowers in large involucres are diagnostic
Habitat and range
Habitat: Serpentine
Elevation: (1000)1500-2300 m
California counties: Trinity, Shasta, Siskiyou
Bloom period
Eriogonum congdonii blooms Jul-Sep.
Conservation status
CNPS 4.3
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 congdonii native to California?
Yes. Eriogonum congdonii is native to California (recorded as native).
When does Eriogonum congdonii bloom?
Eriogonum congdonii blooms Jul-Sep.
Where in California does Eriogonum congdonii grow?
Eriogonum congdonii occurs in Trinity, Shasta, Siskiyou, at elevations of (1000)1500-2300 m.
What plant family does Eriogonum congdonii belong to?
Eriogonum congdonii is in the Polygonaceae family, genus Eriogonum.
Is Eriogonum congdonii rare or endangered?
Eriogonum congdonii carries California Rare Plant Rank 4.3, state rank S4.
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.