Data provided by the participants of the Consortium of California Herbaria

View additional distribution information on the Jepson eflora

Polygonum douglasii is a species of flowering plant in the knotweed family known by the common name Douglas's knotweed. It is native to much of northern and western North America, where it can be found in many types of habitat, including disturbed areas. It has been found in Canada from British Columbia north to Yukon and east as far as Québec, and in the United States as far south as California, New Mexico, Iowa, and New York. Polygonum douglasii is known as a species complex, as there are many subspecies that may be better treated as species in their own right.

Plant type

Annual herb

Size

2 - 31 in Tall

Plant communities

Lodgepole Forest, Red Fir Forest, Sagebrush Scrub, Subalpine Forest, Yellow Pine Forest

Caterpillars
Butterflies

Butterflies and moths supported

3 confirmed and 24 likely

Confirmed Likely

Purplish Copper

Lycaena helloides

Lustrous Copper

Lycaena mariposa

Nivalis Copper

Lycaena nivalis

Garden Webworm Moth

Achyra rantalis