Place of floweringFields and footpaths, Seashore, Low mountains
Flowering seasonSeptember, October
What is Reynoutria multiflora
Reynoutria multiflora or Chinese Knotweed (scientific name: Reynoutria multiflora) is a native of China and a naturalized perennial vine wildflower belonging to the family Polygonaceae and the genus Reynoutria. In Japan, it is found scattered along roadsides and in vacant lots from Honshu to Okinawa.
The dried tuberous root is used to make the crude drug "kashu" , and the vine is used to make the Chinese herbal remedy for insomnia "yakōtō". Care should be taken to avoid overconsumption of either as it can lead to toxic-induced hepatitis.
The genus name "Polygonum" is a compound of the Latin words "polys" (many) and "gonu" (joint), meaning "many joints," and the species name "multiflora" is a compound of the Latin words "multi" (many) and "flora" (flower), meaning "many-flowered.
Common name: Reynoutria multiflora, scientific name: Reynoutria multiflora, also known as Chinese Knotweed, "kashu (crow)", Plant of original: Chinese, habitat: Honshu to Shikoku, Kyushu, Okinawa, environment: fields, roadsides, vacant land, living forms: Vine: 100-300 cm; leaf color: dark green; leaf texture: leaf stalk: long; leaf length: 3-7 cm; leaf width: 1-2 cm; leaf shape: arrowhead to heart-shaped; leaf margin: entire; inflorescence: alternate, dioecious; inflorescence shape: raceme to conical; inflorescence length: 10-20 cm; petals (petal-like sepals): none Inflorescence form: raceme to conical inflorescence; inflorescence length: 10-20 cm; petals (sepals that look like petals): none; sepals: 5; flowering season: August to October; sepal color: white to greenish white; flower diameter: 0.7 cm; number of stamens: 8; number of pistils: 1; flower column: 3; fruit shape: thin; fruit length: 0.3 cm; fruit color: black; reproduction method: seeds or underground stems; uses: tuberous root is used as a tonic herbal drug "Kashu Wu" and the vine as a tonic for insomnia.