1 | Inflorescence a thyrse (most dichasia simple or compound); leaf rachis usually winged or margined |
1' | Inflorescence a panicle or a raceme (all dichasia reduced to a single flower); leaf rachis unwinged |
2 | Petals puberulent to sparsely wooly; disc cup-shaped, 5-lobed |
2' | Petals glabrous; disc annular |