Japanese Knotweed is a large, herbaceous

Herbaceous

A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...

 perennial plant

Perennial plant

A perennial plant or simply perennial is a plant that lives for more than two years. The term is often used to differentiate a plant from shorter lived annuals and biennials. The term is sometimes misused by commercial gardeners or horticulturalists to describe only herbaceous perennials...

, native to eastern Asia in Japan, China and Korea. In North America and Europe the species is very successful and has been classified as an invasive species

Invasive species

"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....

 in several countries.

A member of the family Polygonaceae

Polygonaceae

Polygonaceae is a family of flowering plants known informally as the "knotweed family" or "smartweed family"— "buckwheat family" in the United States. The name is based on the genus Polygonum and was first used by Antoine Laurent de Jussieu in 1789 in his book, Genera Plantarum. The name refers...

, Japanese knotweed has hollow stems with distinct raised nodes that give it the appearance of bamboo

Bamboo

Bamboo is a group of perennial evergreens in the true grass family Poaceae, subfamily Bambusoideae, tribe Bambuseae. Giant bamboos are the largest members of the grass family....

, though it is not closely related. While stems may reach a maximum height of 3–4 m each growing season, it is typical to see much smaller plants in places where they sprout through cracks in the pavement or are repeatedly cut down.