Polygonum minimum

Broadleaf knotweed

Family: Polygonaceae · Type: annual · Native

Broadleaf knotweed is a California native annual found in northwestern California, the California Cascades, and the Sierra Nevada in meadows and open rocky areas at elevations of 700 to 3,500 meters. Flowering from July to September, this plant produces small white or pink flowers near the stem base and along the branches. Growing with wiry, often zigzagged red-brown stems 2 to 30 centimeters tall that are papillate-scabrous and angular, it spreads in a low, prostrate to erect form. Its leaves are densely clustered, narrowly elliptic to round, 6 to 27 millimeters long with flat margins that are irregularly thickened or finely toothed. The fruit is a small, shiny black elliptic to ovate structure 1.8 to 2.3 millimeters long.

Habitat: Meadows, open rocky or +- barren soil

Bloom period: Jul-Sep

Elevation: 700-3500 m

Bioregions: NW, CaR, SN

California counties: Plumas, Tehama, Fresno, Mariposa, Inyo, Siskiyou, Trinity, Tulare, Monterey, El Dorado, Butte, Madera, Mono, Alpine, Humboldt, Nevada, Shasta, Calaveras, Mendocino, Sierra, Glenn, Lassen, Yuba, Placer, Tuolumne, Del Norte, Colusa, Amador, Lake

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