Chorizanthe polygonoides var. polygonoides

Knotweed spineflower, Knotweed Spineflower

Family: Polygonaceae · Type: perennial · Native

Knotweed spineflower is a California native perennial found in northwestern California, the Cascade Range, northern Sierra Nevada foothills, Sacramento Valley, and central western California in sandy or gravelly areas at elevations of 100 to 1,500 meters. Flowering from April to June, this plant produces delicate white flowers with distinctive spiny involucre lobes about 2 to 2.5 millimeters long. Growing with generally green stems and a relatively low, spreading habit, it forms compact clusters across open sandy terrain. Its leaves are small and compact, contributing to the plant's understated yet intricate appearance. The plant's notable chromosomal count of 20 suggests a stable genetic structure typical of its species.

Habitat: Sand or gravel

Bloom period: Apr-Jun

Elevation: 100-1500 m

Bioregions: NW, CaR, n SNF, ScV, CW.

California counties: Sonoma, Modoc, Lake, Nevada, Stanislaus, Tehama, Napa, Marin, Santa Barbara, Butte, Solano, Tuolumne, Amador, El Dorado, Sacramento, San Diego, San Luis Obispo, Santa Clara, Calaveras, Mendocino, Shasta, Alameda, Riverside, San Joaquin, Monterey, Plumas

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Jepson eFlora, Cal-IPC, and more.