Plagiobothrys acanthocarpus
Adobe popcornflower, Adobe Popcornflower
(c) Sula Vanderplank, some rights reserved (CC BY) · licence
Family: Boraginaceae · Type: Herb · Native
Plagiobothrys acanthocarpus (Adobe popcornflower) is a native California herb in the Boraginaceae family, recognized by spiny nutlets with barb-tipped prickles.
Adobe popcornflower is a California native annual found in the Central Valley, eastern San Francisco Bay Area, southern Coast Ranges, and southern California coastal areas in vernal pools and moist clay soils at elevations below 700 meters. Flowering from March to May, this plant produces small white flowers with pale yellow appendages in delicate clusters. Growing with spreading to erect stems 10 to 40 centimeters tall, it has a somewhat taprooted structure with strigose (stiff-hairy) surfaces. Its cauline leaves are slender, measuring 2 to 6 centimeters long, with lower leaves more prominent. The fruit consists of small, ovate nutlets with distinctive irregular net-like cross-ribs and occasional slender, barb-tipped prickles along its surface.
Identification and appearance
Key characters: 38 sympatric species; key feature is spiny nutlets with barb-tipped prickles
Habitat and range
Habitat: Vernal pools, moist clay soil
Elevation: < 700 m
California counties: San Diego, Riverside, Contra Costa, Monterey, Tulare, Los Angeles, Orange, San Luis Obispo, Alameda, San Benito, San Joaquin, Kings, Kern, Stanislaus, Fresno, Madera, Santa Barbara, Tehama, Sacramento, Merced, Solano, Shasta, Calaveras, El Dorado, Mariposa, Tuolumne, Modoc, Ventura, Amador, Alpine, Yuba
Outside California: Mexico
Bloom period
Plagiobothrys acanthocarpus blooms Mar-May.
How to tell it apart
vs Cryptantha: Seeds have a raised ridge down the inner face, not a groove like Cryptantha.; vs Pectocarya: Seeds lack the comb-like marginal barbs of Pectocarya; attachment scar is raised.; vs Myosotis: Flowers are smaller and more tubular; Myosotis has wider, flatter blue flowers with yellow centers.; vs Nemophila: Nemophila has much larger, showier blue-white flowers and broader leaves.; vs Leptosiphon: Leptosiphon has needle-like divided leaves; Plagiobothrys has simple narrow leaves.
Frequently asked questions
Is Plagiobothrys acanthocarpus native to California?
Yes. Plagiobothrys acanthocarpus is native to California (recorded as native).
When does Plagiobothrys acanthocarpus bloom?
Plagiobothrys acanthocarpus blooms Mar-May.
Where in California does Plagiobothrys acanthocarpus grow?
Plagiobothrys acanthocarpus occurs in San Diego, Riverside, Contra Costa, Monterey, Tulare, Los Angeles, Orange, San Luis Obispo and other counties, at elevations of < 700 m.
What plant family does Plagiobothrys acanthocarpus belong to?
Plagiobothrys acanthocarpus is in the Boraginaceae family, genus Plagiobothrys.
What habitat does Plagiobothrys acanthocarpus grow in?
Plagiobothrys acanthocarpus grows in Vernal pools, moist clay soil.
Related species
Other California species in the same genus, family, or bioregion.
- Plagiobothrys arizonicus — Arizona popcornflower
- Plagiobothrys austiniae — Austin's spiny-nut popcornflower
- Plagiobothrys bracteatus — Bracted popcornflower
- Plagiobothrys canescens — Grey popcorn flower
- Plagiobothrys canescens var. canescens — Valley popcornflower
- Plagiobothrys canescens var. catalinensis — Santa catalina popcornflower
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.