oriental ladysthumb

Polygonales > Polygonaceae > Polygonum caespitosum Blume
Synonym(s): Asiatic smartweed, bristled knotweed, bunchy knotweed

Oriental ladysthumb is an annual forb that can reach 6-30 in. (15.2-76.2 cm) in height and can be either erect or sprawling. 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. Flowering occurs from June to October, when pink flowers develop at the apex of the stems. Flowers are 1/8 in. (0.3 cm) long and occur in groups. Oriental ladysthumb is native to Asia and occurs in disturbed habitats such as along roadsides and in pastures. Plants also inhabit wet areas.


Identification, Biology, Control and Management Resources

  • Weeds of the Week - USDA Forest Service, Northeastern Area, Forest Health Protection

Selected Images from Invasive.org

Click on each thumbnail to download the image at 1536x1024 resolution or below for available resolutions.
Use 768x512 for Microsoft PowerPoint and use 1536x1024 for Prints and Publications.

Flower(s);
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
768x512

Plant(s);
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
768x512

Infestation;
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
768x512

Invasive Reference(s):

Check Invasive.org for most current lists.
  • Connecticut - Noxious Weed Law
  • Georgia - EPPC list
  • Kentucky - EPPC List
  • Tennessee - EPPC List
  • Virginia - Invasive Alien Plant Species
  • Mid-Atlantic - EPPC List
  • Invasive Plant Atlas of New England


External Links


footer line
USDA Forest Service Bugwood University of Georgia