Persicaria
knotweed, smartweed, tearthumb
7 species
1 subspecies and varieties
1 subspecies and varieties
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Persicaria amphibia – water smartweed
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east to the Atlantic Coast.
Habitat: River, stream, lake, and pond margins in water to 2 meters deep to adjacent moist uplands.
Origin: Native
Flowers: July-October
Growth Duration: Perennial
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east to the Atlantic Coast.
Habitat: River, stream, lake, and pond margins in water to 2 meters deep to adjacent moist uplands.
Origin: Native
Flowers: July-October
Growth Duration: Perennial
Persicaria hydropiper – smartweed, mild water-pepper
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across most of North America to the Atlantic Coast.
Habitat: Shores, swales, ditches, and disturbed ground.
Origin: Introduced from Europe
Flowers: July-September
Growth Duration: Annual
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across most of North America to the Atlantic Coast.
Habitat: Shores, swales, ditches, and disturbed ground.
Origin: Introduced from Europe
Flowers: July-September
Growth Duration: Annual
Persicaria hydropiperoides – water pepper, swamp smartweed
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to Mexico and South America, east across North America to the Atlantic coast.
Habitat: Moist to swampy areas, often growing in mud, from the lowlands to the lower mountain valleys.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to Mexico and South America, east across North America to the Atlantic coast.
Habitat: Moist to swampy areas, often growing in mud, from the lowlands to the lower mountain valleys.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Persicaria lapathifolia – dock-leaf smartweed, pale smartweed, willow weed
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Streambanks, pond and lakeshores and other wet places.
Origin: Native
Flowers: May-September
Growth Duration: Perennial
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Streambanks, pond and lakeshores and other wet places.
Origin: Native
Flowers: May-September
Growth Duration: Perennial
Persicaria maculosa – heartweed, lady's-thumb, spotted lady's-thumb, redshank
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: A weedy species, usually on moist, cultivated or otherwise disturbed soil.
Origin: Introduced from Eurasia
Flowers: March-September
Growth Duration: Perennial
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: A weedy species, usually on moist, cultivated or otherwise disturbed soil.
Origin: Introduced from Eurasia
Flowers: March-September
Growth Duration: Perennial
Persicaria punctata – dotted knotweed, dotted smartweed, water smartweed
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to the Atlantic Coast.
Habitat: Lake and pond shores, marshes, and wet forests.
Origin: Native
Flowers: June-September
Growth Duration: Annual, Perennial
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to the Atlantic Coast.
Habitat: Lake and pond shores, marshes, and wet forests.
Origin: Native
Flowers: June-September
Growth Duration: Annual, Perennial
Persicaria wallichii – garden knotweed
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to California; also in eastern North America.
Habitat: Waste areas, roadsides, and other disturbed areas where often where somewhat moist.
Origin: Introduced from eastern Asia
Flowers: July-October
Growth Duration: Perennial
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to California; also in eastern North America.
Habitat: Waste areas, roadsides, and other disturbed areas where often where somewhat moist.
Origin: Introduced from eastern Asia
Flowers: July-October
Growth Duration: Perennial
• var. wallichii – garden knotweed, Himalayan knotweed
