1	"Flowers unisexual, the plant monoecious with creeping or floating stems; aquatic or semi-aquatic"	"Rumex bidens"
1	"Flowers bisexual; the plant tap-rooted, terrestrial but often growing in poorly drained sites"	2
2	"Flowers (at least at the upper nodes of the inflorescence) in false whorls of 1-4"	"Rumex dumosus"
2	"Flowers in false whorls of 5-16 at all nodes"	3
3	"Fruiting valves entire"	4
3	"Fruiting valves with marginal teeth or spines"	5
4	"Panicle divaricate, the floral whorls distant, usually leaf-subteneded; fruiting valve with callosities almost equalling the values"	"Rumex conglomeratus"
4	"Panicle with erect branches, floral whorls ± distant below, crowded above; fruiting valves with callosities ± half as long as the valves"	"Rumex crispus"
5	"Fruiting valves with hooked teeth on margins and at apex"	"Rumex brownii"
5	"Fruiting perianth without hooks on the marginal teeth, the apex acute or obtuse"	6
6	"Lamina of basal leaves usually constructed at about the mid-point; inflorescence divaricately branched; pedicels ± equalling the fruiting valves, articulated at the mid-point"	"Rumex pulcher"
6	"Lamina of basal leaves not constructed; inflorescence branches ± erect; pedicels longer than the fruiting valves, articulated below the mid-point"	"Rumex obtusifolius"