1 | Leaves 3-5-plinerved, at base subpeltate. Climbing shrub; axillary tendrils often present |
1' | Leaves penninerved (if ± 3-plinerved a tree), never peltate. Tendrils absent. |
2 | Stamens and staminodes present |
2' | Stamens present; staminodes absent. |
3 | Stamens fully fused into a tube. Flowers unisexual, plant monoecious |
3' | Stamens not fused (sometimes partly adnate to the petals). Flowers generally bisexual. |
4 | Stamens 8 or 10, half of them epipetalous, the other half episepalous. Leaves usually mucronulate at apex. Spines and/or thorns generally present |
4' | Stamens all epipetalous. Leaves not mucronulate at apex. Spines and/or thorns absent. |
5 | Flowers interruptedly arranged in elongate spikes |
5' | Flowers arranged in short racemes, panicles, or mostly in fascicles. |
6 | Stamens 8 or 10, arranged in pairs before each petal |
6' | Stamens 4-7, solitary before each petal. |
7 | Petals entirely free |
7' | Petals fused in the lower half. |
8 | Calyx cupular, ± truncate to very shortly 6-dentate. Petals thick-fleshy. Anthers apically penicillate |
8' | Calyx indistinct, merely a rim with minute teeth. Flower supported by an epicalyx consisting of 3 concrescent bracts. Petals thin. Anthers not penicillate at apex |