Eriastrum calocyanum
Pretty blue woolly-star
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Family: Polemoniaceae · Type: Annual · Native
Eriastrum calocyanum (Pretty blue woolly-star) is a native California annual in the Polemoniaceae family.
Pretty blue woolly-star is a California native annual found in the central Coast Ranges and southern Sierra Nevada foothills in open benches along creeks, chaparral, and mixed woodland at elevations of 400 to 1,300 meters. Flowering from May to June, this plant produces light blue or lavender to deep royal blue flowers with delicate white throats, often featuring a dark reddish or purplish spot at the base of each petal. Growing 4 to 25 centimeters tall with erect, sometimes branched stems that have a distinctive zig-zag form and are densely covered in woolly hairs. Its leaves are 7 to 35 millimeters long, also woolly in texture, and can be entire or divided into 4 linear to thread-like lobes. The small capsule fruit is approximately 3 to 4 millimeters long, containing a single seed in each chamber.
Identification and appearance
Key characters: Geographically isolated - 0 sympatric species
Habitat and range
Habitat: Open benches along creeks, chaparral, mixed woodland
Elevation: 400-1300 m
Bloom period
Eriastrum calocyanum blooms May-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 calocyanum native to California?
Yes. Eriastrum calocyanum is native to California (recorded as native).
When does Eriastrum calocyanum bloom?
Eriastrum calocyanum blooms May-Jun.
What plant family does Eriastrum calocyanum belong to?
Eriastrum calocyanum is in the Polemoniaceae family, genus Eriastrum.
What habitat does Eriastrum calocyanum grow in?
Eriastrum calocyanum grows in Open benches along creeks, chaparral, mixed woodland.
Related species
Other California species in the same genus, family, or bioregion.
- Eriastrum densifolium — Perennial woolly-star
- Eriastrum densifolium subsp. austromontanum — Mountain woolly-star
- Eriastrum densifolium subsp. densifolium — Perennial woolly-star
- Eriastrum densifolium subsp. elongatum — Elongate woolly-star
- Eriastrum densifolium subsp. mohavense — Mojave woolly-star
- Eriastrum densifolium subsp. patens — Spreading woolly-star
Sources: Jepson eFlora · Index of California Plant Names · 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.