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1 Spikelets 2.2-7 mm long; glumes 3- to 5-nerved; hilum elliptic
..2 Ligule 3-7 mm long, acute; spikelets 2.2-4.8 mm long, triangular; plant annual, lacking rhizomes; lemma with broad margins clearly distinct from the gibbous back, apex usually strongly curved; palea with translucent thick trichomes between the keels, rarely glabrous; lemma with translucent thick trichomes on the back, rarely glabrous; basal innovations intravaginal
..2 Ligule 0.5-2.5 mm long, truncate; spikelets 4-7 mm long, ovate; plant perennial, with rhizomes; lemma with broad margins distinct from the slightly gibbous back, apex not curved; palea glabrous, rarely with translucent thick trichomes between the keels; lemma usually glabrous on the back, rarely with translucent thick trichomes; basal innovations extravaginal