| Fallopia sachalinensis | |
|---|---|
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Eudicots |
| (unranked): | Core eudicots |
| Order: | Caryophyllales |
| Family: | Polygonaceae |
| Genus: | Fallopia |
| Species: | F. sachalinensis |
| Binomial name | |
| Fallopia sachalinensis F.Schmidt |
|
Fallopia sachalinensis (Giant Knotweed or Sakhalin Knotweed Japanese オオイタドリ ooitadori, Russian Горец сахалинский, Гречиха сахалинская; syn. Polygonum sachalinense F.Schmidt, Reynoutria sachalinensis (F.Schmidt) Nakai) is a species of Fallopia native to northeastern Asia in northern Japan (Hokkaidō, Honshū) and the far east of Russia (Sakhalin and the southern Kurile Islands).[1]
It is a herbaceous perennial plant growing to 2–4 m tall, with strong, extensively spreading rhizomes forming large clonal colonies. The leaves are 15–40 cm long and 10–28 cm broad, nearly heart-shaped, with a somewhat wavy, crenate margin. The flowers are small, produced on short, dense panicles up to 10 cm long in late summer or early autumn; it is dioecious, with male and female flowers on separate plants. It is closely related to Fallopia japonica, and can be distinguished from it by its larger size, and in its leaves having a heart-shaped (not straight) base and a crenate margin. It has a chromosome count of 2n=44.[2][3]
The shoots are tender and edible. It was introduced to Europe and grown in many botanic gardens. It came prominently into notice about 1893, when a drought in western Europe caused a decided shortage in forage for cattle. This plant was little affected, and since its tender shoots and leaves were eaten by stock, the plant was widely grown experimentally as a forage crop. It has proved less useful than was predicted, and its deliberate cultivation has been almost entirely abandoned.[4] It has, however, like F. japonica, proved to be an invasive weed in several areas.[5]
It has hybridised with Fallopia japonica in cultivation; the hybrid, Fallopia × bohemica (Chrtek & Chrtková) J.P.Bailey, is frequently found in the British Isles and elsewhere.[2][6]