cultivated knotweed
(Persicaria wallichii)
This species is Introduced in the United States
Appearance
Persicaria wallichii is a perennial plant that can grow from 23.6-78.7 in. (60-200 cm) tall.
Foliage
Leaves are alternate or basal, oval to lanceolate in shape, moderately hairy, and 3.9-7.9 in. (10-20 cm) long with heart-shaped bases and pointed tips.
Flowers
Flowers are white to pink, 0.12-0.2 in. (3-5 mm) long, fragrant, and found in clusters from 7.9-13.8 in. (20-35 cm) long. Flowers bloom from mid-summer to late fall.
Fruit
Seeds are dark brown in color, ovoid, 3 angled, smooth, and 0.04-0.08 in. (1-2 mm) long. They are transported mostly by water and wind.
Ecological Threat
Persicaria wallichii can be found in moist soils and in fields, pastures, and waste areas. It is native to the Himalayan region.
Selected Images
Maps
EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit www.eddmaps.org
State Lists - This map identifies those states that have this species on their invasive species list or law.
Invasive Listing Sources
Taxonomic Rank
| Domain: Eukarya |
| Kingdom: Plantae |
| Phylum: Magnoliophyta |
| Class: Magnoliopsida |
| Superorder: Caryophyllanae |
| Order: Caryophyllales |
| Family: Polygonaceae |
| Genus: Persicaria |
| Persicaria wallichii |
Synonyms and Other Names
Other Common Names:
Himalyan knotweed
Related Scientific Names:
Polygonum polystachyum Wallich ex Meisn. (Synonym)