Multitribe: Answers to key questions leading to this tribe. 

	Mature inflorescence, if breaking into units, then the units not as below; NOT [Mature inflorescence breaking into spikelet units consisting of a sessile fertile spikelet, a hairy pedicel with or without a sterile spikelet at tip, and a hairy rachis joint, all arising at the same point (a node) in specialized panicle branches called rames]
	Spikelets not as below; sterile florets if present, either located distal to the fertile floret(s) on the rachilla or paired and attached at the base of a single fertile floret, not paired with the upper glume as below; lemma and palea variously textured, enclosing the flower or not; disarticulation usually above the glumes; NOT [Spikelets usually dorsally compressed, appearing 1-flowered but containing 1 fertile floret and 1 sterile floret, the latter attached to the base of fertile floret opposite the upper glume, resembling the upper glume, and together with the upper glume enveloping the fertile floret; lower glumes minute (sometimes absent) to 3/4 as long as upper glumes and typically wrapping most of the way around the pedicel at base; fertile floret seed-like with chartaceous-indurate lemma and palea enclosing flower and fruit; disarticulation below the glumes with rare exceptions]
	Spikelets 1 to many-flowered, subtended by a pair of glumes (only 1 on lateral spikelets in Lolium); palea margins enclosed or not; plants of dry or wet habitats; NOT [Spikelets 1-flowered, lacking glumes; margins of the palea tightly enclosed by the lemma margins on female or perfect florets; plants of wetlands, often emergent aquatic]
	Inflorescence not as below; if a terminal spike, then the lateral spikelets attached edgewise to the rachis with inner (upper) glume wanting (as in Lolium); NOT [Inflorescence a terminal spike with sessile or subsessile spikelets attached broadside at nodes on opposite sides of the rachis]
	Lemmas and lemma awns not as below; if lemma indurate and enveloping the floret, then glumes distinctly dorsally compressed and calluses glabrous (as in Milium); NOT [Lemmas stiff to indurate, firmer than the glumes, surrounding the palea and often overlapping along the margins, closed at the tip as well as at the base, often pubescent; lemma awns (caducous or wanting in some species) terete and encircled at the base by the closed tip of the lemma; calluses usually pubescent, rarely glabrous]

Group3: Answers to key questions leading to this group. 

	If plants mat-forming, then inflorescences not as below; NOT [Mat-forming annuals or perennials either with clusters of spikelets hidden by sharp-pointed leaves at branch tips, or with pistillate inflorescences consisting of burs partially hidden within expanded leaf sheaths with only the staminate inflorescences exceeding the upper leaves]
	Inflorescence not as below, the spikelets usually on pedicels in panicles that range from spike-like to open; if spikelets sessile, then they either have more than 1 fertile floret per spikelet or are not arranged like the teeth of a comb; NOT [Inflorescence consisting of spike-like panicle branches with sessile- subsessile, closely imbricate, regularly-spaced, parallel spikelets all directed toward 1 side of the branch like the teeth of a comb (loosely so in Bouteloua curtipendula); fertile florets 1 per spikelet]
	Spikelets with more than 1 fertile floret; sterile florets if present, attached above the fertile florets (Phragmites, with sterile florets attached above and below fertile florets, is an exception); NOT [Spikelets with 1 fertile floret; sterile florets if present, attached above or below the fertile floret]

Bromus: Answers to key questions leading to this genus. 

	Inflorescence a panicle with all spikelets subtended by 2 glumes; NOT [Inflorescence a terminal spike; lateral spikelets positioned edgewise to the rachis and lacking a glume on inside edge]
	Spikelets usually pedicellate; if sessile-subsessile, then not arranged as below; NOT [Spikelets sessile or subsessile on spike-like panicle branches, or on short secondary branches in dense one-sided clusters at branch tips]
	Rachillas glabrous or pubescent; if pubescent, then hairs much shorter than the lemmas; panicles and plants not as below; NOT [Rachillas with silky hairs (4) 6-10 mm long, as long as the lemmas or nearly so; panicles 15-35 (45) cm long, 8-20 cm wide at maturity, dense, feathery; plants 10-30 (40) dm tall, with stout, creeping rhizomes and often forming dense stands]
	Glumes < 17 mm long; if glumes longer, then plants perennial; NOT [Glumes 18-32 mm long, usually exceeding the lemmas; plants annual]
	Plants with the below combination of characteristics: Culm sheaths closed to near summit; leaf blades flat; spikelets 12-40 (55) mm long; lemmas 7-14 (21) mm long, usually awned, the awns terminal or subterminal; calluses glabrous; ovaries and caryopses with pubescent apical appendage; caryopses adnate to paleas at maturity

Inermis: Answers to key questions leading to this species

	Plants perennial; culms solitary to loosely tufted; lemmas unawned or with awns attached just below the apex and projecting at most 7 (8) mm beyond it; lemma apex entire, emarginate or bifid with teeth <= 0.5 mm long; anthers 1-7 mm long; NOT [Plants annual; culms tufted; lemma awns attached at least 1.5 mm below the apex and 8-18 mm long; lemma apex bifid with teeth 0.5 to 2 (3) mm long; anthers 0.5-1.5 mm long]
	Culms solitary or a few together from creeping rhizomes; NOT  [Culms loosely tufted, rhizomes absent]
	Lemmas usually glabrous, sometimes sparsely pubescent on margins and rarely on back; leaf blades glabrous, rarely pubescent or pilose, 11-35 (42) cm long, 5-15 mm wide; sheaths usually glabrous, rarely pubescent or pilose; glumes glabrous; NOT  [Lemmas sparsely to densely pubescent on lower back and margins, sometimes pubescent only on margins and nerves; leaf blades usually pilose and scabrous adaxially, 9-17 (25) cm long, (3) 4-8 (9) mm wide; sheaths pilose or glabrous; glumes usually glabrous, occasionally hirsute]