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Modoc County Knotweed
(Polygonum polygaloides ssp. esotericum )

Modoc County Knotweed; Photo Copyright 2000 Robert E. Preston, Ph.D.
Photo Copyright 2000 Robert E. Preston, Ph.D.

Description: Smooth annual 2-3/8 to 5-1/2 inches (6-14 cm) high; leaves linear 3/8 inch (8-10 mm) long; bracts leafy, 1/8 inch (2-5 mm) long, white margined. Flowering spike 3/4 to 2-3/4 inches (2-7 cm) long; stamens 8; fruit dark shiny brown, angled, 1/16 inch (2 mm) long.

 Identifying Features

  1. White margined bracts;
  2. Stamens 8.

Distribution: Modoc County. Within public lands administered by the Alturas Field Office near Leonard Spring northeast of Alturas. Known from several locations in Devil's Garden area and northwest of Canby along Highway 139.

Habitat: Seasonally dry adobe flats and pond basins in sagebrush scrub and juniper woodland from 4,500 to 5,000 feet (1372 to 1524 meters).

Flowering Period: July - August

Similar Plants: Polygonum polygaloides ssp. confertiflorum is similar but has 3 stamens and bracts are not white margined.

Status: BLM Sensitive, California Native Plant Society List 1B



Glossary of
Plant Terms

Diagram of Plant Parts

Definitions of
Plant Status

Field Office: Alturas

Last updated: 08-05-2010