Polygonum ramosissimum subsp. prolificum

Family: Polygonaceae · Type: annual · Not Native

Proliferating knotweed is a naturalized annual found in northern Sierra Nevada (Lake Tahoe area) and San Francisco Bay bioregions in wet, saline places at elevations of 100 to 2,000 meters. Flowering from June to October, this plant produces white to pink flowers in small clusters with 2 to 4 crowded blooms. Growing with erect blue-green stems 10 to 80 centimeters tall, it develops stems that darken to dark brown or black when dry. Its leaves are distinctive, with oblanceolate blades 8 to 30 millimeters long, 4 to 6 millimeters wide, having rounded or obtuse tips that are notably longer than the flowering branches. The fruit is small, measuring 1.6 to 2 millimeters long, with a shiny or dull surface that can be smooth or slightly rough.

Habitat: Wet, saline places

Bloom period: Jun-Oct

Elevation: 100-2000 m

Bioregions: n SNH (Lake Tahoe area), SnFrB

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