| 1 | Style undivided or very shortly bilobed |
| 1' | Style deeply bifid |
| 2 | Inflorescence paniculate, racemiform, or spiciform. Lowest flower hermaphrodite, upper one(s) male. Anther-cells completely filled with pollen. |
| 2' | Inflorescence a single terminal globose or semiglobose head. Lowest flower female, upper one(s) male. Anther-cells destitute of pollen at the ± attenuate base. Spp. 5-10 |
| 3 | Inflorescence paniculate. Spikelets in small fascicles. Hypogynous bristles rigid, antrorsely scabrous. Spikelets 2-4-flowered. Spp. 1-3 |
| 3' | Inflorescence racemiform or spiciform. Spikelets in dense globose heads, stellately spreading. Hypogynous bristles capillary, smooth or almost so. Spikelets 1-flowered. Sp. 4. |
| 4 | Hypogynous bristles present. Nut finely transversely wavy-wrinkled. Sp. 11. |
| 4' | Hypogynous bristles absent. Nut transversely rugose. Sp. 12 |
