Plagiobothrys diffusus
San francisco popcornflower, San Francisco Popcornflower
Family: Boraginaceae · Type: Annual · Native
Conservation status: CNPS 1B.1
Plagiobothrys diffusus (San francisco popcornflower) is a native California annual in the Boraginaceae family, recognized by coastal endemic, large flowers with yellow appendages, spreading bracts.
San francisco popcornflower is a rare (CNPS 1B.1) California native annual found in central Coast and west-central San Francisco Bay bioregions in moist places and seeps at elevations of 30 to 150 meters. Flowering from April to June, this plant produces white flowers with small yellow appendages in delicate clusters. Growing prostrate to ascending with slender stems 5 to 25 centimeters long, it has a strigose (stiff-hairy) appearance. Its cauline leaves are generally 5 to 10 centimeters long, with spreading bracts throughout the plant. The tiny nutlets are ovate, approximately 1 to 1.5 millimeters long, ranging from tan to gray with subtle ridges and net-like surface textures.
Identification and appearance
Key characters: 15 sympatric species; coastal endemic, large flowers with yellow appendages, spreading bracts
Habitat and range
Habitat: Moist places, seeps
Elevation: 30-150 m
California counties: San Francisco, Santa Cruz, San Mateo
Bloom period
Plagiobothrys diffusus blooms Apr-Jun.
Conservation status
CNPS 1B.1
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 diffusus native to California?
Yes. Plagiobothrys diffusus is native to California (recorded as native).
When does Plagiobothrys diffusus bloom?
Plagiobothrys diffusus blooms Apr-Jun.
Where in California does Plagiobothrys diffusus grow?
Plagiobothrys diffusus occurs in San Francisco, Santa Cruz, San Mateo, at elevations of 30-150 m.
What plant family does Plagiobothrys diffusus belong to?
Plagiobothrys diffusus is in the Boraginaceae family, genus Plagiobothrys.
Is Plagiobothrys diffusus rare or endangered?
Plagiobothrys diffusus carries California Rare Plant Rank 1B.1, state rank S1.
Related species
Other California species in the same genus, family, or bioregion.
- Plagiobothrys distantiflorus — Madera popcornflower
- Plagiobothrys fulvus var. campestris — Field popcornflower
- Plagiobothrys glaber — Hairless popcornflower
- Plagiobothrys glyptocarpus — Sculptured-nut popcornflower
- Plagiobothrys glyptocarpus var. glyptocarpus — Sculptured allocarya
- Plagiobothrys glyptocarpus var. modestus — Cedar ridge popcornflower
Sources: Jepson eFlora · CNPS Rare Plant Inventory · Index of California Plant Names · CalPhotos · CDFW CNDDB
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.