Chorizanthe howellii
Howell's spineflower
(c) Spencer Hurt, some rights reserved (CC BY) · licence
Family: Polygonaceae · Type: Herb · Native
Conservation status: CNPS 1B.2 · Endangered
Chorizanthe howellii (Howell's spineflower) is a native California herb in the Polygonaceae family, recognized by very low elevation coastal dunes, broad leaves, straight awns.
Howell's spineflower is a rare (CNPS 1B.2) California native perennial found in central Mendocino County coastal dunes at elevations below 20 meters. Flowering from May to July, this plant produces white to rose-colored flowers with delicate, minutely toothed petals. Growing as a low, tufted plant spreading 1 to 5 meters in diameter with branches generally spreading or decumbent, it reaches 3 to 10 centimeters tall. Its leaves are predominantly basal, with spoon-shaped to widely obovate blades 1 to 3 centimeters long and 0.5 to 1.5 centimeters wide, creating a distinctive low-growing mound. The plant's dense, rounded flower clusters and hairy texture make it a unique feature of coastal dune environments.
Identification and appearance
Key characters: 4 sympatric species; very low elevation coastal dunes, broad leaves, straight awns
Habitat and range
Habitat: Coastal dunes
Elevation: < 20 m
California counties: Mendocino
Bloom period
Chorizanthe howellii blooms May-Jul.
Conservation status
CNPS 1B.2 · Endangered
How to tell it apart
vs Eriogonum: Chorizanthe has 1 flower per involucre; Eriogonum has multiple flowers per involucre.; vs Eremothera: Chorizanthe has 6-parted flowers in spiny cups; Eremothera has 4-petaled evening-primrose flowers.; vs Calyptridium: Chorizanthe has flowers in awned involucres; Calyptridium has naked flowers with papery sepals.; vs Lastarriaea: Chorizanthe has thin papery flowers; Lastarriaea has distinctly thick, leathery-textured flowers.; vs Navarretia: Chorizanthe is in Polygonaceae with 6-parted flowers; Navarretia is in Polemoniaceae with 5-lobed tubular flowers.
Frequently asked questions
Is Chorizanthe howellii native to California?
Yes. Chorizanthe howellii is native to California (recorded as native).
When does Chorizanthe howellii bloom?
Chorizanthe howellii blooms May-Jul.
Where in California does Chorizanthe howellii grow?
Chorizanthe howellii occurs in Mendocino, at elevations of < 20 m.
What plant family does Chorizanthe howellii belong to?
Chorizanthe howellii is in the Polygonaceae family, genus Chorizanthe.
Is Chorizanthe howellii rare or endangered?
Chorizanthe howellii carries California Rare Plant Rank 1B.2, state rank S1.
Related species
Other California species in the same genus, family, or bioregion.
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.