1 | Inflorescence with a long distinct peduncle; petals free and regular; stamens free |
1' | Inflorescence sessile or almost so; petals connate or only 3, free; stamens adnate to corolla tube |
2 | Corolla with 5 equal obtuse lobes, shorter than tube; fertile stamens 5, anthers sessile on tube (not in the Guianas, see family distribution) |
2' | Corolla zygomorphic, lobes bifid and bicucullate, exceeding tube in length; fertile stamens 3 or 5, anthers on slender filaments |