Edge/ Japanese Knotweed

COMMON NAME: Japanese Knotweed

OTHER COMMON NAME(S): Mexican Bamboo

SCIENTIFIC NAME: Polygonum cuspidatum

FAMILY: Polygonaceae

COMMUNITY: Edge

STATUS: Naturalized  from Japan

LIFESPAN: Perennial

HEIGHT: 3 to 9 feet

FLOWERING TIME: May to late September

FRUITING TIME: Late August to late September

DISTRIBUTION: Eastern Canada to North Carolina and west along Mississippi River ~ Statewide in NJ

IDENTIFYING CHARACTERISTICS: Tall shrublike growing in dense coarse-stemmed stands ~  Leaves broad, oval shaped with pointed tips ~ Flowers greenish white growing in slender fingerlike clusters ~ Stems hollow like bamboo with enlarged joints, mottled green dusted with white ~ stout rhizome

GENERAL INFORMATION: Members of this family (Polygonaceae), commonly called the Buckwheat or Smartweed family, include 51 genera and 1,150 species.  Polu means “many” and gonu means “knee” for the swollen stem joints of many species.  Food plants in this family include Buckwheat, Sorrel and Rhubarb. The young shoots (up to 1 foot) are edible steamed or boiled and served like asparagus.  Slightly older stems can be peeled and the sour rind boiled with sugar and pectin to make a rhubarb-like jam. Roots bark can be used to make dye.

Please note: While harvesting wild berries/fruit is permitted at Island Beach State Park, visitors must adhere to park regulations at all times and must not damage vegetation or go off designated trails.  This information is presented for educational purposes.