| Scientific Name: | Fallopia japonica ( syn. Reynoutria ) |
| Common Name: | Japanese knotweed |
| Family Name: | Polygonaceae |
| Origin: | S.E. Asia / Japan / China |
| Hardiness Zone: | Zone 5: (-29 to -23 °C) |
| Plant Type: | Herbaceous perennial, Invasive plant, Shrub - deciduous, Weed (horticultural) |
| Mature Size: | 2 - 3m x 7 - 10m (height x width) |
| Habit: | Upright |
| Form: | Oval - vertical, Round |
| Texture: | Medium - coarse |
| Landscape Uses: | |
| Exposure: | Full sun, Part sun/part shade, Filtered shade, Deep shade |
| Soil or Media: | |
| Leaves: | Simple, Alternate, Soft flexible, Glabrous, Ovate, Entire |
| Flowers: | Panicle, White, Aug-Sep |
| Fruit: | Capsule, White, Brown, Sep-Oct |
| Key ID Features: | |
| Stems hollow, bamboo-like, arising from rhizomes; leaves have a straight base (truncate), apex with an abruptly pointed tip, undersides have small ridges or bumps on veins or margins, up to 17cm long; florets creamy-white, 2-3mm wide, in panicles arising from leaf axils that are about 15cm long. (Giant knotweed, F. sachalinensis, is very similar but larger). | |