Eriogonum butterworthianum
Butterworth's buckwheat
(c) Matt Berger, some rights reserved (CC BY) · licence
Family: Polygonaceae · Type: Shrub · Native
Conservation status: CNPS 1B.3
Eriogonum butterworthianum (Butterworth's buckwheat) is a native California shrub in the Polygonaceae family, recognized by sheathing leaves, large tomentose involucres (5-6mm), very restricted sandstone habitat.
Butterworth's buckwheat is a rare (CNPS 1B.3) California native shrub found in the northern Santa Lucia Range in central Monterey County's sandstone habitats at elevations of 650 to 700 meters. Flowering from June to September, this plant produces cream to rose-colored flowers in compact clusters approximately 3 to 5 millimeters long. Growing as a low subshrub 10 to 40 centimeters tall with a dense spread of 10 to 40 centimeters, it features woolly tomentose stems and branches. Its small leaves are dense and tomentose, measuring 5 to 20 millimeters long and 1 to 4 millimeters wide, with a sheathing base. The fruit is smooth and measures 3 to 3.5 millimeters long.
Identification and appearance
Key characters: Co-occurs with 33 species; key features are sheathing leaves, large tomentose involucres (5-6mm), very restricted sandstone habitat
Habitat and range
Habitat: Sandstone
Elevation: 650-700 m
California counties: Monterey
Bloom period
Eriogonum butterworthianum blooms Jun-Sep.
Conservation status
CNPS 1B.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 butterworthianum native to California?
Yes. Eriogonum butterworthianum is native to California (recorded as native).
When does Eriogonum butterworthianum bloom?
Eriogonum butterworthianum blooms Jun-Sep.
Where in California does Eriogonum butterworthianum grow?
Eriogonum butterworthianum occurs in Monterey, at elevations of 650-700 m.
What plant family does Eriogonum butterworthianum belong to?
Eriogonum butterworthianum is in the Polygonaceae family, genus Eriogonum.
Is Eriogonum butterworthianum rare or endangered?
Eriogonum butterworthianum carries California Rare Plant Rank 1B.3, state rank S2.
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.