Eriastrum sapphirinum subsp. ambiguum
Short-bract woolly-star
Photo: parent species Eriastrum sapphirinum · Photo by Chez Brungraber
Family: Polemoniaceae · Type: Annual · Native
Eriastrum sapphirinum subsp. ambiguum (Short-bract woolly-star) is a native California annual in the Polemoniaceae family, recognized by glandular hairs on stems and slightly asymmetric flowers are key features.
Short-bract woolly-star is a California native annual found in desert scrub and arid woodland across open areas, slopes, and floodplains at elevations of 390 to 2,200 meters. Flowering from April to July, this delicate plant produces striking flowers in blue, lavender, and white hues, with petals often featuring darker blue or purple spots and veins. Growing 3.5 to 25 centimeters tall with erect to spreading branches, it has a woolly texture that becomes sparser as the plant matures. Its leaves range from 6 to 44 millimeters long, varying from entire to multi-lobed, with lower leaves typically having fewer lobes than upper leaves. The plant's small capsule fruit and distinctive flower coloration make it a charming and intricate component of arid California landscapes.
Identification and appearance
Key characters: 24 sympatric species - glandular hairs on stems and slightly asymmetric flowers are key features
Habitat and range
Habitat: Open areas on slopes, floodplains, flats near washes, disturbed areas, in desert scrub, arid woodland
Elevation: 390-2200 m
Bloom period
Eriastrum sapphirinum subsp. ambiguum blooms Apr-Jul.
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 sapphirinum subsp. ambiguum native to California?
Yes. Eriastrum sapphirinum subsp. ambiguum is native to California (recorded as native).
When does Eriastrum sapphirinum subsp. ambiguum bloom?
Eriastrum sapphirinum subsp. ambiguum blooms Apr-Jul.
What plant family does Eriastrum sapphirinum subsp. ambiguum belong to?
Eriastrum sapphirinum subsp. ambiguum is in the Polemoniaceae family, genus Eriastrum.
What habitat does Eriastrum sapphirinum subsp. ambiguum grow in?
Eriastrum sapphirinum subsp. ambiguum grows in Open areas on slopes, floodplains, flats near washes, disturbed areas, in desert scrub, arid woodland.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CalPhotos
Last updated 2026-10-01
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.