Polygonum ramosissimum subsp. ramosissimum

Family: Polygonaceae · Type: annual · Native

Knotweed is a California native annual found in northern California Coast Ranges, San Francisco Bay Area in disturbed places and saline marshes at elevations below 200 meters. Flowering from July to September, this plant produces white to yellow or pink flowers clustered in spike-like inflorescences with small flowers 2 to 5 millimeters long. Growing with yellow-green stems reaching 30 to 200 centimeters tall, it develops branching stems with distinctive height variations between main and branch stems. Its leaves are narrowly elliptic to lanceolate, measuring 35 to 70 millimeters long with blade widths of 7 to 18 millimeters, featuring acute to acuminate tips. The fruit is small, shiny or dull, and measures 2.5 to 3.5 millimeters in length.

Habitat: Disturbed places, saline marshes

Bloom period: Jul-Sep

Elevation: < 200 m

Bioregions: n CA-FP, SnFrB

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