Oriental lady's thumb
(Persicaria longiseta )
This species is Introduced in the United States
Appearance
Persicaria longiseta is an annual forb that can reach 6-30 in. (15.2-76.2 cm) in height and can be either erect or sprawling.
Foliage
Leaves are elongate, narrow and pointed at the base and tip. Stems have swollen nodes with papery sheaths (ocrea). Ocrea have long, hair-like bristles on the margin.
Flowers
Flowering occurs from June to October, when pink flowers develop at the apex of the stems. Flowers are 0.13 in. (0.3 cm) long and occur in groups.
Fruit
Seeds are smooth, dark colored, dry, and 3 angled.
Ecological Threat
Persicaria longiseta is native to Asia and occurs in disturbed habitats such as along roadsides and in pastures. Plants also inhabit wet areas.
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
- Georgia Exotic Pest Plant Council - Category 4
- Invasive Plant Species of West Virginia
- Jil M. Swearingen, Survey of invasive plants occurring on National Park Service lands, 2000-2007
- New Hampshire Invasive Plant Species Watch List
- Non-Native Invasive Plants of the City of Alexandria, Virginia
- Nonnative Invasive Species in Southern Forest and Grassland Ecosystems
- Pennsylvania Department of Conservation and Natural Resources Invasive Plants
- Virginia Invasive Plant Species List
- WeedUS - Database of Plants Invading Natural Areas in the United States
- West Virginia Invasive Species Strategic Plan and Volunteer Guidelines 2014
- West Virginia Native Plant Society, Flora West Virginia Project, and West Virginia Curatorial Database System, September 3, 1999
Taxonomic Rank
Domain: Eukarya |
Kingdom: Plantae |
Phylum: Magnoliophyta |
Class: Magnoliopsida |
Superorder: Caryophyllanae |
Order: Caryophyllales |
Family: Polygonaceae |
Genus: Persicaria |
Persicaria longiseta |
Synonyms and Other Names
Other Common Names:
Asiatic smartweed, bristled knotweed, bunchy knotweed
Related Scientific Names:
Polygonum cespitosum var. longisetii (Bruijn) A.N. Steward (Misspelling)
Polygonum cespitosum var. longisetum (Bruijn) Danser (Misspelling)
Persicaria cespitosum var. longisetum (Bruijn) A.N. Steward (Synonym)
Persicaria longisetum Bruijn (Synonym)
Polygonum caespitosum var. longisetum (Bruijn) Steward (Synonym)
References
Common Name Reference:
Scientific Name Reference: The Plant List (2010). Version 1. Published on the Internet; http://www.theplantlist.org/ (accessed 1st January).