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Biology & Ecology
Facts
Scientific names include:
- Knotweeds are members of the Buckwheat Family (Polygonaceae) that originate from volcanic regions of Asia
- All species of knotweeds are extremely fast growers, reaching heights of 6 -15 within a single growing season. Plants usually attain their full height by June - July, and go to flower in July/August
- Growth typically starts in early April, but may start later at higher elevation
- Commons names often include False Bamboo, Elephant Ear, and Fleeceflower
Scientific names include:
- Bohemian knotweed (Polygonum X bohemicum)
- Giant knotweed (Polygonum sachalinense)
- Himalayan knotweed (Polygonum polystachyum)
- Japanese knotweed (Polygonum cuspidatum)
- Depending on the size, age, and site location of the plant, rhizomes can penetrate up to 7 feet into the soil, making control very difficult
- Flowers are grown out of leaf axils, and are white to greenish in color
- Leaves are alternate and bright green
- Manual control activities tend to aggravate the plant
- Plants can send up young shoots late into the growing season, especially in response to treatment activities
- Plants die back after the first major frost of the year
- Rhizomes are brittle and orange in color, much like that of a carrot
- Rhizomes can send out shoots up to 20 - 25 feet away from the mother plant
- Stems are thick and hollow, resemble bamboo, and are green to reddish in color
- Tall, very aggressive perennial species
- While plants are dormant for the winter, the dead brown canes persist throughout the winter months, creating an unattractive landscape