1	"Perianth segments 3-5, not in 2 distinct whorls"	2
1	"Perianth segments 6, in 2 distinct whorls"	6
2	"Woody shrubs or perennials with cane-like stems; flowers unisexual or functionally so"	3
2	"Annual or perennial herbs; flowers bisexual"	4
3	"Plants with cane-like stems; outer perianth segments winged"	Fallopia
3	"Climbing, straggling or prostrate shrubs; outer perianth segments not winged"	Muehlenbeckia
4	"Plant twining; outer perianth segments winged"	Fallopia
4	"Plant not twining; outer perianth segments not winged"	5
5	"Ochreae silvery or pale brown; flowers solitary or a few together in leaf axils; perianth segments green with white margins"	Polygonum
5	"Ochreae brown or hyaline; flowers in groups subtended by ochreolae, arranged in terminal or axillary spike-like panicles or spikes; perianth segments pink or whitish"	Persicaria
6	"Fruiting perianth with a hard, 3-angled tube; outer segments spreading, spinous"	Emex
6	"Fruiting perianth with outer segments smaller than the inner, not spinous"	7
7	"Flowers bisexual"	8
7	"Flowers unisexual"	9
8	"Plant not climbing; inner perianth segments not membranous and greatly enlarged in fruit"	Rumex
8	"Plant climbing; inner perianth segments membranous, net-veined, greatly enlarged in fruit"	Acetosa
9	"Plant monoecious"	Rumex
9	"Plant dioecious or rarely polygamous"	Acetosella