Eriogonum umbellatum var. dumosum
American valley sulphur flower, American Valley Sulphur Flower
Photo: parent species Eriogonum umbellatum · Photo by Chez Brungraber
Family: Polygonaceae · Type: Shrub · Native
Eriogonum umbellatum var. dumosum (American valley sulphur flower) is a native California shrub in the Polygonaceae family, recognized by shrub form at moderate elevations helps distinguish from mat-forming varieties.
American valley sulphur flower is a California native shrub found in the Klamath Ranges, northern Coast Ranges, Cascade Range, northern Sierra Nevada, and Modoc Plateau in sandy or gravelly habitats at elevations of 600 to 1,200 meters. Flowering from June to September, this plant produces distinctive yellow flowers in compact umbels 3 to 10 centimeters in diameter. Growing as a low, spreading shrub 3 to 5 decimeters tall with grayish tomentose stems, it forms dense mounded clusters in open terrain. Its leaves are small, measuring 1 to 2.5 centimeters long, with a soft tomentose underside that gives the plant a silvery-gray appearance. The dense clusters of bright yellow flowers emerge from woolly branches, creating a striking contrast against its pale foliage.
Identification and appearance
Key characters: 110 sympatric species; shrub form at moderate elevations helps distinguish from mat-forming varieties
Habitat and range
Habitat: Sand or gravel
Elevation: (300)600-1200 m
Outside California: south-central Oregon
Bloom period
Eriogonum umbellatum var. dumosum blooms Jun-Sep.
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 umbellatum var. dumosum native to California?
Yes. Eriogonum umbellatum var. dumosum is native to California (recorded as native).
When does Eriogonum umbellatum var. dumosum bloom?
Eriogonum umbellatum var. dumosum blooms Jun-Sep.
What plant family does Eriogonum umbellatum var. dumosum belong to?
Eriogonum umbellatum var. dumosum is in the Polygonaceae family, genus Eriogonum.
What habitat does Eriogonum umbellatum var. dumosum grow in?
Eriogonum umbellatum var. dumosum grows in Sand or gravel.
Related species
Other California species in the same genus, family, or bioregion.
- Eriogonum umbellatum var. furcosum — Sierra nevada sulphur flower
- Eriogonum umbellatum var. glaberrimum — Warner mountains buckwheat
- Eriogonum umbellatum var. goodmanii — Goodman's sulphur flower
- Eriogonum umbellatum var. humistratum — Mount eddy buckwheat
- Eriogonum umbellatum var. juniporinum — Juniper sulphur-flowered buckwheat
- Eriogonum umbellatum var. lautum — Scott valley buckwheat
Sources: Jepson eFlora · CalPhotos
Last updated 2026-09-30
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.