| 1 | Both glumes present, placed side by side and entirely covering the floret |
| 1' | Lower glume suppressed (except in the terminal spikelet), the upper entirely covering the floret |
| 2 | Outer keel of the glumes distinctly winged; anthers 0.5-0.8 mm long |
| 2' | Outer keel of the glumes not winged; anthers 0.5-1 mm long |
