Reynoutria Houtt.

4. Reynoutria Houtt. View in CoL 1

Perennials with extensive subterranean rhizomes and stout, erect annual stems. Functionally dioecious, but with conspicuous rudiments of stamens in the female and of gynaeceum in the male flowers. Flowers in relatively small axillary panicles. Perianth accrescent; segments 5, the outer 3 keeled, eventually winged. Stamens 8. Styles 3, distinct; stigmas fimbriate. Leaves seldom more than 12 cm, acuminate-cuspidate; flowers

white 1. japonica Leaves usually more than 15 cm, acute or somewhat acuminate;

flowers greenish 2. sachalinensis