Polygonum polygaloides subsp. esotericum

Modoc county knotweed, Modoc County Knotweed

Family: Polygonaceae · Type: annual · Native

Conservation status: CNPS 1B.3

Modoc county knotweed is a rare (CNPS 1B.3) California native annual found in the Modoc Plateau near Goose Lake and Sierra Valley in seasonally wet places and pinyon/juniper woodland at elevations around 1,500 meters. Flowering from June to August, this delicate plant produces white to pink flowers in narrow cylindric clusters 2 to 10 millimeters long. Growing with slender stems 5 to 12 centimeters tall, it forms compact, low-growing populations in seasonal wetland habitats. Its small leaves have appressed bracts 4 to 8 millimeters long with prominent green veins and rigid lance-elliptic shapes. The fruit is a dark-brown, lanceolate seed 2 to 2.5 millimeters long with a subtle net-like surface texture.

Habitat: Vernal pools, seasonally wet places, pinyon/juniper woodland

Bloom period: Jun-Aug

Elevation: +- 1500 m.

Bioregions: MP (near Goose Lake, Modoc Co. Sierra Valley, s Plumas Co.).

California counties: Modoc, Sierra, Plumas, Shasta

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