Polygonum spergulariiforme

Spurry knotweed

Family: Polygonaceae · Type: annual · Native

Spurry knotweed is a California native annual found in northwestern California, the Cascade Range, northern Sierra Nevada, San Francisco Bay Area, and western Modoc Plateau in open, rocky places including serpentine habitats at elevations of 10 to 2,000 meters. Flowering from June to October, this plant produces delicate pink or white flowers in dense, spike-like clusters with 2 to 5 crowded blooms. Growing 5 to 50 centimeters tall with widely spreading green branches, it has a distinctively papillate-scabrous stem that becomes smoother with age. Its linear to lanceolate leaves are narrow, measuring 35 to 60 millimeters long and 1 to 3 millimeters wide, with flat or slightly rolled margins and acute, mucronate tips. The fruit is a shiny black, narrow elliptic seed 3 to 5 millimeters long with smooth to slightly striated surfaces.

Habitat: Open, rocky places (including serpentine)

Bloom period: Jun-Oct

Elevation: 10-2000 m

Bioregions: NW, CaR, n SN, SnFrB, w MP

California counties: Nevada, Trinity, Lassen, Modoc, Humboldt, Lake, Siskiyou, Del Norte, Marin, Butte, Plumas, Shasta, El Dorado, Mendocino, Napa, Tuolumne, Sierra, Tehama, Mono

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