Japanese Knotweed

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Caryophyllales

Polygonaceae (Dock)

Amphibious Bistort, Broad-leaved Dock, Clustered Dock, Common Bistort, Common Knotgrass, Common Sorrel, Curled Dock, Equal-leaved Knotgrass, Garden Rhubarb, Lesser Knotweed, Pale Persicaria, Red Bistort, Redleg, Russian Vine, Sheep Sorrel, Water Dock, Wood Dock

Flower

2 metres tall

Farmland, meadows, riversides, roadsides, towns, wasteland, waterside, wetland, woodland.

Small and white, 5 petals. Forming branched spikes at the bases of the upper leaves.

3-angled seeds contained within a white winged papery encasing. Ripens around September.

The leaves can grow as large as 40cm long and 25cm wide. They grow alternate along the stems and are heart-shaped, toothless and have pointed tips. The young leaves are dark red. As the leaves being to mature, they turn green but the red veins persist a little longer. Eventually the entire leaf turns green, including the veins. The stems on which the leaves emerge from are zigzagged, changing directions at every leaf node. The mature stems are hollow.

Fragrant flowers which attract bees.

American Bamboo, Asian Knotweed, Asiatic Knotweed, Bombascus, Donkey Rhubarb, Elephant Ear's, False Bamboo, Fleeceflower, Gypsy Rhubarb, Hancock's Curse, Himalayan Fleece Vine, Itadori, Japanese Bamboo, Japanese Fleeceflower, Japanese Polygonum, Kontiki Bamboo, Mexican Bamboo, Monkey Fungus, Monkeyweed, Pea Shooters, Sally Rhubarb.

Common  

Lesser Knotweed