Eriastrum diffusum
Spreading woolly-star
Photo by Chez Brungraber
Family: Polemoniaceae · Type: Herb · Native
Eriastrum diffusum (Spreading woolly-star) is a native California herb in the Polemoniaceae family, recognized by . Key features: thin wiry brown stems, yellow throat, diffuse branching pattern.
Spreading woolly-star is a California native annual found in the southern eastern desert and desert bioregions in open sandy areas at elevations below 2,000 meters. Flowering from March to June, this delicate plant produces white to blue flowers with yellow throats, often featuring reddish dots or stripes at the base, in small terminal clusters of 3 to 20 blossoms. Growing with thin, wiry erect or spreading stems 1 to 25 centimeters tall, it has a diffusely branched habit that can vary from densely woolly to nearly smooth. Its leaves are relatively small, ranging 4 to 26 millimeters long, with few lateral lobes measuring 1 to 7.5 millimeters. The fruit is a small tan capsule approximately 2.7 to 4 millimeters long, containing angular seeds.
Identification and appearance
Key characters: 9 sympatric species. Key features: thin wiry brown stems, yellow throat, diffuse branching pattern
Habitat and range
Habitat: Open areas, sandy soil
Elevation: < 2000 m.
California counties: San Bernardino, San Diego, Inyo, Mono, Riverside, Kern, Imperial, San Luis Obispo
Outside California: to Colorado, Texas; northern Mexico.
Bloom period
Eriastrum diffusum blooms Mar-Jun.
How to tell it apart
vs Navarretia: Eriastrum has fluffy white woolly hairs; Navarretia has spine-tipped bracts and leaves without woolly hairs.; vs Gilia: Eriastrum flower clusters are densely woolly-hairy; Gilia flower clusters lack woolly hairs.; vs Loeseliastrum: Eriastrum has woolly tufted hairs and radial flowers; Loeseliastrum has simple hairs and bilateral flowers.; vs Langloisia: Eriastrum has woolly tufted white hairs; Langloisia has stiff branched bristly hairs.; vs Petalonyx: Eriastrum has opposite lobed leaves in Polemoniaceae; Petalonyx has alternate simple leaves in Loasaceae.
Frequently asked questions
Is Eriastrum diffusum native to California?
Yes. Eriastrum diffusum is native to California (recorded as native).
When does Eriastrum diffusum bloom?
Eriastrum diffusum blooms Mar-Jun.
Where in California does Eriastrum diffusum grow?
Eriastrum diffusum occurs in San Bernardino, San Diego, Inyo, Mono, Riverside, Kern, Imperial, San Luis Obispo, at elevations of < 2000 m..
What plant family does Eriastrum diffusum belong to?
Eriastrum diffusum is in the Polemoniaceae family, genus Eriastrum.
What habitat does Eriastrum diffusum grow in?
Eriastrum diffusum grows in Open areas, sandy soil.
Related species
Other California species in the same genus, family, or bioregion.
- Eriastrum diffusum subsp. coachellae — Coachella woolly-star
- Eriastrum diffusum subsp. diffusum — Spreading woolly-star
- Eriastrum eremicum subsp. eremicum — Desert woolly-star
- Eriastrum ertterae — Lime ridge woolly-star
- Eriastrum filifolium — Thread-leaved woolly-star
- Eriastrum harwoodii — Harwood's woolly-star
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.