| 1 | Leaves opposite; stipules absent |
| 1' | Leaves spirally arranged; stipules or stipule scars present |
| 2 | Leaf blade margin crenate to serrate with 20-40 short teeth. Fruit lobes horned with stigma remnants |
| 2' | Leaf blade margin entire. Fruits without appendices |
| 3 | Leaf blade apex caudate, lower surface glabrous. Stamens 10-14, filaments free. Stigmas spade-like |
| 3' | Leaf blade apex rounded to apiculate, lower surface sericeous. Stamens 28-68, filaments united. Stigmas petal-like |
