Plagiobothrys glaber
Hairless popcornflower
Family: Boraginaceae · Type: Herb · Native
Conservation status: CNPS 1A
Plagiobothrys glaber (Hairless popcornflower) is a native California herb in the Boraginaceae family, recognized by extinct species with thick hollow stems, greatly enlarged fruiting sepals.
Hairless popcornflower is a rare (CNPS 1A) California native annual found in central coastal California and southern San Francisco Bay areas, specifically around Hollister, in wet, saline coastal marshes at elevations below 100 meters. Flowering from April to May, this plant produces small white flowers approximately 3 millimeters in diameter with delicate white petals. Growing with ascending to erect stems 10 to 20 centimeters tall that are thick and hollow, it has a sparse and short-strigose appearance. Its cauline leaves are relatively small, measuring 2 to 11 millimeters long, with lower leaves positioned along the stem. The fruit consists of shiny, dark brown nutlets 1.8 to 2 millimeters long, with distinctive narrow ridges and subtle cross-ribs, representing one of the last known populations of this presumed nearly extinct species.
Identification and appearance
Key characters: 27 sympatric species; extinct species with thick hollow stems, greatly enlarged fruiting sepals
Habitat and range
Habitat: Presumed extinct. Wet, saline, +- alkaline soils in valleys, coastal marshes
Elevation: < 100 m
California counties: San Benito, Alameda, Marin, Santa Clara
Bloom period
Plagiobothrys glaber blooms Apr-May.
Conservation status
CNPS 1A
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 glaber native to California?
Yes. Plagiobothrys glaber is native to California (recorded as native).
When does Plagiobothrys glaber bloom?
Plagiobothrys glaber blooms Apr-May.
Where in California does Plagiobothrys glaber grow?
Plagiobothrys glaber occurs in San Benito, Alameda, Marin, Santa Clara, at elevations of < 100 m.
What plant family does Plagiobothrys glaber belong to?
Plagiobothrys glaber is in the Boraginaceae family, genus Plagiobothrys.
Is Plagiobothrys glaber rare or endangered?
Plagiobothrys glaber carries California Rare Plant Rank 1A, state rank SX.
Related species
Other California species in the same genus, family, or bioregion.
- Plagiobothrys glyptocarpus — Sculptured-nut popcornflower
- Plagiobothrys glyptocarpus var. glyptocarpus — Sculptured allocarya
- Plagiobothrys glyptocarpus var. modestus — Cedar ridge popcornflower
- Plagiobothrys greenei — Greene's spiny-nut popcornflower
- Plagiobothrys hispidulus — Harsh popcornflower
- Plagiobothrys humistratus — Low popcornflower
Sources: Jepson eFlora · CNPS Rare Plant Inventory · Index of California Plant Names · CalPhotos · CDFW CNDDB
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.