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1 Spikelets often in pairs with one subsessile and one pedicellate floret (or a mix of both if 3 florets present within a spikelet); awns of the lemma arising from midway to just below the lemma apices; lemma apices bifid; plants annual
1 Spikelets pedicellate; if awns present, then arising from just below the lemma apices; lemma apices bifid or not; plants usually perennial, rarely winter annuals.
..2 Spikelets 5-9.5 mm long; second lemma with an awn 3.5-7 mm long
..2 Spikelets 1.5-5 (-5.2) mm long; second lemma awnless, or infrequently with an awn up to 1 mm long (S. nitida) or 3.5-4 mm long (S. filiformis, S. ×pallens), but otherwise awnless.
....3 Lower leaf blades usually involute, mostly (10-) 15-45 cm long, < 2 mm wide
............ 7 Panicle densely cylindrical; second glume 2-3× as long as wide, rounded or truncate at the tip; lowermost rachilla internode 0.5-0.7 mm long