Chorizanthe polygonoides
Knotweed spineflower
(c) Matt Berger, some rights reserved (CC BY) · licence
Family: Polygonaceae · Type: Herb · Native
Chorizanthe polygonoides (Knotweed spineflower) is a native California herb in the Polygonaceae family.
Knotweed spineflower is a California native perennial found in open grasslands and dry meadows at low elevations. Flowering from April to June, this delicate plant produces white to rose-colored flowers that are tiny, less than 2 millimeters long, with rounded perianth lobes. Growing as a compact tufted plant, it spreads 10 to 20 centimeters in diameter with ascending to prostrate branches emerging from its base. Its basal leaves are small and narrow, measuring 3 to 10 millimeters long and 2 to 3 millimeters wide, with an oblanceolate to elliptic shape. The plant forms intricate clusters with involucres that have distinctive 3-angled shapes and 5 to 6 lobes, some with hooked awns giving it a delicate, intricate appearance.
Habitat and range
California counties: Marin, Butte, Riverside, Sonoma, Tehama, Mendocino, San Luis Obispo, San Diego, Shasta, Santa Clara, El Dorado, Lake, Nevada, Monterey
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 polygonoides native to California?
Yes. Chorizanthe polygonoides is native to California (recorded as native).
Where in California does Chorizanthe polygonoides grow?
Chorizanthe polygonoides occurs in Marin, Butte, Riverside, Sonoma, Tehama, Mendocino, San Luis Obispo, San Diego and other counties.
What plant family does Chorizanthe polygonoides belong to?
Chorizanthe polygonoides is in the Polygonaceae family, genus Chorizanthe.
Related species
Other California species in the same genus, family, or bioregion.
- Chorizanthe polygonoides var. longispina — Long-spined spineflower
- Chorizanthe polygonoides var. polygonoides — Knotweed spineflower
- Chorizanthe procumbens — Prostrate spineflower
- Chorizanthe pungens — Monterey spineflower
- Chorizanthe pungens var. hartwegiana — Ben lomond spineflower
- Chorizanthe pungens var. pungens — Monterey spineflower
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.