Polygonum cuspidatum

Common Name: 
Japanese knotweed, Japanese bamboo, Mexican knotweed, Mexican bamboo
Scientific Name: 
Polygonum cuspidatum Sieb. & Zucc., syn. Fallopia japonica
Family Name: 
Polygonaceae - Smartweed or Buckwheat Family
Identification Notes
Life Cycle
introduced perennial, reproducing by seed and extensive rhizomes
Stems
upright, tall, smooth, noticeably jointed, hollow between nodes, reddish-purple mottling, ocrea (papery or membranous sheath) at nodes
Stems of Japanese Knotweed
Stems of Japanese Knotweed
Stems of Japanese Knotweed
Stems of Japanese Knotweed
Stems of Japanese Knotweed
Stems of Japanese Knotweed
Stems of Japanese Knotweed
Stems of Japanese Knotweed
Leaves
alternate, ovate, tip pointed, square base
Leaves of Japanese Knotweed
Flowers
greenish-white, unisexual, petals absent; panicle clusters, axillary
Flowers of Japanese Knotweed
Flowers of Japanese Knotweed
Seed Pods
triangular, 3 "wings"
Seed Pods of Japanese Knotweed