Water Knotweed

Polygonum amphibium L.

Buckwheat family

Plant Type

Forb/herb

Life Cycle

Perennial

Mature Height

4.0 feet

Flower Color

Red, Pink

Bloom Time

Late Spring, Early Summer, Mid Summer, Late Summer

Growing Conditions

Light

Shade Tolerance Intolerant

Water

Water Use High

Soil

CaCO3 Tolerance Medium

Ecosystem & Wildlife

Pollinators Native Bees; Bombus; Honey Bees; Beetles, Wasps, Flies; Moths; Butterflies; Larval Host (Butterfly)

Larval Host Epidemia helloides, Hyllolycaena hyllus

Native Range

USA: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, District of Columbia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode I., South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, West Virginia, Wisconsin, Wyoming
CAN: Alberta, British Columbia, Newfoundland, Manitoba, New Brunswick, Newfoundland, Northwest Territorie, Nova Scotia, Ontario, Prince Edward I., Québec, Saskatchewan, Yukon
MEX: Mexico Central, Mexico Northeast, Mexico Northwest, Mexico Southeast, Mexico Southwest

Regional Native Status: L48 (N), AK (N), CAN (N), SPM (N)

State-level native status is based on data available through Plants of the World Online. Regional Native Status comes from the USDA Plants Database. For more detailed native status information, please refer to BONAP.