1 | Perennial, robust grass, sometimes reaching a height of 1.5 m; culms bulbous at the base |
1' | Annual grasses, reaching a height of c. 1 m; culms not conspicuously bulbous at the base |
2 | Spikelets of 2 kinds: the basal very much reduced, the upper in groups, with sterile spikelets surrounding a single fertile one |
2' | Spikelets all similar |
3 | Wings of the glumes toothed or undulate; ligule 6-8 mm long |
3' | Wings of the glumes entire; ligule up to 5 mm long |
4 | Empty lemmas at the base of the fertile floret oblong-acute, c. 3 mm long |
4' | Empty lemmas at the base of the fertile floret ovate-acute, c. 1 mm long |