1 Awns of the lemmas 1 mm long, essentially a minute prolonged extension of the lemma midvein; lemma apices acute

1 Awns of the lemmas 2-8 mm long (therefore conspicuous and not merely a minute midvein extension), bent or geniculate and often basally-twisted and exceeding lemma apices; lemma apices bifid or bicuspidate.

  2 Lower and upper glumes subequal, both 4-5 mm long; lemma awns arising from midlength to just below the teeth; plant an annual, without sterile shoots; [rare waif]

  2 Lower and upper glumes unequal, the lower glume shorter than the upper glume (sometimes only 0.5-1.0 mm shorter as in Trisetum aureum, but otherwise conspicuously shorter), 2.0-5.5 mm long (lower glume), 2.5-7 mm long (upper glume); lemma awns arising from the upper 1/3 of the lemmas; plants annual and without sterile shoots OR perennial with both fertile and sterile shoots; [widespread]

    3 Spikelets 2.5-3.5 mm long; lemma awns 2-6 mm long; plants annuals, without sterile shoots

    3 Spikelets 4-8 mm long; lemma awns 3-9 mm long; plants perennial, with both fertile and sterile shoots.

      4 Panicles usually glistening yellowish-brown; spikelets usually with 2 florets (sometimes 3); panicles 5-20 cm long; leaves evenly distributed; ligules 0.5-1(2) mm, obtuse, lacerate, sometimes ciliolate; plants sometimes with rhizomes to 7 cm long; [occurring sporadically in disturbed sites]

      4 Panicles usually silvery-shiny; spikelets usually with 3 florets (sometimes 2 or 4); panicles (5)20-30(50) cm long; leaves mostly basal or evenly distributed; ligules 0.5-4 mm, truncate or rounded; plants not rhizomatous; [cool, moist northern sites, rare and disjunct in high elevation areas s. to VA]