Plagiobothrys trachycarpus

Rough-nutlet popcornflower

Family: Boraginaceae · Type: Herb · Native

Plagiobothrys trachycarpus (Rough-nutlet popcornflower) is a native California herb in the Boraginaceae family, recognized by prostrate habit, large leaves, and vernal pool habitat.

Rough-nutlet popcornflower is a California native annual found in southern San Joaquin Valley, San Francisco Bay Area, southern Coast Ranges, southern California, western Transverse Ranges, and Peninsular Ranges in shallow vernal pools, grasslands, scrub, chaparral, and woodland habitats at elevations up to 1,390 meters. Flowering from March to May, this plant produces small white flowers with yellow appendages approximately 1.5 to 4 millimeters in diameter. Growing with prostrate to ascending stems 5 to 40 centimeters long and covered in dense strigose hairs, it has distinctive cauline leaves primarily found on the lower stem. Its leaves spread 5 to 10 centimeters along the stem, with the plant forming a somewhat dense, spreading growth pattern. The fruit consists of small, wide-ovate nutlets with intricate surface ridges and granular-papillate textures, each nutlet measuring 1 to 1.7 millimeters wide.

Identification and appearance

Key characters: 37 sympatric species - distinguished by prostrate habit, large leaves, and vernal pool habitat

Habitat and range

Habitat: Shallow vernal pools, wet places in grassland, scrub, chaparral, woodland

Elevation: < 1390 m

California counties: San Luis Obispo, Monterey, Contra Costa, Merced, Kern, Placer, San Diego, Sacramento, Marin, Alameda, San Joaquin, San Benito, Stanislaus, Santa Barbara, Humboldt, Santa Clara, Ventura, Solano

Bloom period

Plagiobothrys trachycarpus 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 trachycarpus native to California?

Yes. Plagiobothrys trachycarpus is native to California (recorded as native).

When does Plagiobothrys trachycarpus bloom?

Plagiobothrys trachycarpus blooms Mar-May.

Where in California does Plagiobothrys trachycarpus grow?

Plagiobothrys trachycarpus occurs in San Luis Obispo, Monterey, Contra Costa, Merced, Kern, Placer, San Diego, Sacramento and other counties, at elevations of < 1390 m.

What plant family does Plagiobothrys trachycarpus belong to?

Plagiobothrys trachycarpus is in the Boraginaceae family, genus Plagiobothrys.

What habitat does Plagiobothrys trachycarpus grow in?

Plagiobothrys trachycarpus grows in Shallow vernal pools, wet places in grassland, scrub, chaparral, woodland.

Related species

Other California species in the same genus, family, or bioregion.

All Plagiobothrys species · All Boraginaceae

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.