| 1 | Inflorescences or infructescences axillary, depauperate-paniculate or racemose-like. Hypocarp stalk-like |
| 1' | Inflorescences or infructescences terminal, sometimes also axillary, often much branched. |
| 2 | Leaves glabrous, sometimes sparsely puberulous or pubescent on the lower surface. |
| 2' | Leaves densely, sometimes sparsely, tomentose or pubescent, velutinous, rarely hispidulous, on the lower surface. |
| 3 | Papillae on the lower leaf surface concentrated in small groups in the areolae, separated by veins and veinlets. Hypocarp obconical |
| 3' | Papillae on the lower leaf surface rather uniform, not concentrated into such groups in the areolae. Hypocarp discoid |
| 4 | Flower-buds subglobose. Petals imbricate. Hypocarp obconical (solid). |
| 4' | Flower-buds oblong or ellipsoid. Petals valvate. Hypocarp discoid, short-cupular, or funnel-shaped (hollow). |
| 5 | Petals glabrous, rarely puberulous outside. Disk round and flat in ♂. Fertile anthers (1-)1¼-1½ mm long |
| 5' | Petals puberulous outside. Disk short-cupular in ♂. Fertile anthers ½-¾ mm long. |
| 6 | Leaves tomentose and usually glabrescent on the lower surface. Petals elliptic-oblong, or -lanceolate, sometimes ± oblong, 3½-5 by 1-1½ mm |
| 6' | Leaves velutinous on the lower surface. Petals ovate-oblong or lanceolate, 2½-3½ by ⅔-1¼ mm |
