Reynoutria sachalinensis (F. Schmidt ) Ronse Decraene
giant knotweed
Polygonaceae (Buckwheat family)
Introduction to Vascular Plants
giant knotweed
Polygonaceae (Buckwheat family)
Introduction to Vascular Plants
Species Information
General:
Perennial herb from a rhizome; stems erect, numerous, branched, 2-4 m tall, reddish, hollow.
Leaves:
Basal leaves lacking; stem leaves alternate, 10-30 cm long, the blades widely egg-shaped, the bases heart-shaped, the tips gradually tapered, long stalked; stipules tubular, entire.
Flowers:
Flowers in small axillary panicles; perianths 2-3 mm long, pale green or greenish-white, unequally 5-lobed, the outer lobes strongly winged.
Fruits:
Achenes, 3-angled, about 3 mm long, black, smooth and shiny.
Illustration
If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.
Illustration Source: The Illustrated Flora of British Columbia
Habitat and Range
Mesic fields, roadsides and waste places in the lowland zone; infrequent on Vancouver Island, the Gulf Islands and the Vancouver area, rare on the midcoast (Prince Rupert); introduced from Asia.Status Information
Synonyms
Synonyms and Alternate Names:
Fallopia sachalinensis