1	"Leaf blades with divergent veins; spikelet unisexual and dimorphic, pistillate lemmas with uncinate hairs; plants native to southeastern Florida (Pharoideae)"	"Phareae {Pharus glaber}"
1	"Leaf blades with parallel veins; spikelets bisexual, unisexual, or modified into plantlets, pistillate spikelets never with uncinate hairs; plants native, introduced, or cultivated throughout the Flora region"	2
2	"Culms perennial, woody or tough but not evidently woody, often developing complex branching systems; leaves dimorphic, thoseon the upper portion of the culms or distal on the branches usually pseudopetiolate (Bambusoideae)"	3
2	"Culms usually annual, sometimes facultatively perennial, rarely woody, sometimes branching from the upper nodes but the branching system not complex; leaves usually not pseudopetiolate"	5
3	"Culms tough but not woody, to 1(3) m tall or climbing; blades of distal leaves often folding at night or under stress; in North America north of Mexico, plants known only in cultivation"	"Olyreae {Lithachne humilis}"
3	"Culms woody, to 30 m tall; leaves strongly dimorphic, those of the main culms (culm leaves) with expanded sheaths and often with reduced, non-photosynthetic blades, those of the branches (foliage leaves) not folding at night or under stress; plants native or introduced and cultivated or escaped"	4
4	"Rhizomes pachymorphic or, if leptomorphic, culms flat or conspicuously sulcate above the branches; branch complements of 2(3) subequal branches or several to many, usually with 1-3 dominant branches; glumes more than 2"	Bambuseae
4	"Rhizomes leptomophic; culms terete or inconspicuously longitudinally grooved; branch complements of 1-3 branches, secondary branches, if present, subequal; glumes 2"	Arundinarieae
5	"Spikelets almost always with 2 florets, lower florets in the spikelets always sterile or staminate, frequently reduced to lemmas, occasionally missing, the upper florets bisexual, staminate, or sterile, unawned or awned from the lemma apices or, if the lemmas bilobed, from the sinuses; glumes membranous and the upper lemmas stiffer than the lower lemmas or both florets reduced and concealed by the stiff to coriaceous glumes; rachilla not prolonged beyond the second floret (Panicoideae)"	6
5	"Spikelets either with other than 2 florets, if with 2, the lower floret bisexual or the upper floret awned from the back or base of the lemma; rachilla often prolonged beyond the distal floret; lemma texture various"	7
6	"Glumes flexible, membranous, the lower glumes usually shorter than the upper glumes, sometimes missing, the upper glumes usually subequal to or exceeded by the upper floret; upper lemmas and paleas well-developed, usually indurate to coriaceous, sometimes membranous; spikelets single or in pairs, all pedicellate, often shortly so (includes Paspaleae)"	Paniceae
6	"Glumes indurate, often subequal, at least 1 and usually both exceeding the florets; both lemmas hyaline; paleas hyaline or absent; most spikelets in pairs or triplets, 1 spikelet in each group usually sessile; pedicels shorter or only a little longer than the sessile spikelets"	Andropogoneae
7	"Spikelets with 1 floret; lemmas terminating in a 3-branched awn (the lateral awns sometimes greatly reduced); callus well-developed; ligules usually of hairs, sometimes ciliate membranes, the cilia longer then the membranous base (Aristidoideae)"	"Aristideae {Aristida}"
7	"Spikelets with more than 1 floret or, if only 1, the lemma not terminating in a 3-branched awn; callus development various; ligules various"	8
8	"Spikelets with 1 functional floret; glumes absent or less than 1/4 as long as the floret; lower glumes, if present, always without veins, upper glumes, if present, veinless or 1-veined"	9
8	"Spikelets usually with more than 1 functional floret; 1 or both glumes often longer than 1/4 the length of the adjacent floret and/or with more than 1 vein"	13
9	"Upper glumes present, 1-veined; lower glumes absent or much shorter than the upper glumes and lacking veins (Pooideae)"	"Brachyelytreae {Brachyelytrum}"
9	"Both glumes absent or lacking veins"	10
10	"Inflorescences 1-sided spikes; spikelets solitary, triangular in cross section, radial to the rachises (Pooideae)"	"Nardeae {Nardus stricta}"
10	"Inflorescences panicles; spikelets laterally compressed or terete"	11
11	"Culms aerenchymatous, 20-500 cm long; plants of wet places, often emergent or floating, at least distally; lemmas 5-10-veined; paleas 3-10 veined (Ehrhartoideae, in part)"	Oryzeae
11	"Culms not aerenchymatous; plants of wet or dry habitats but not emergent or floating; lemmas 1-5-veined; paleas 2-veined"	12
12	"Culms 2-19 cm tall; plants of cold or damp habitats, not rhizomatous; caryopses exposed at maturity"	Poeae
12	"Culms 5-300 cm tall; plants usually of warm or dry habitats, often rhizomatous; caryopses not exposed at maturity; lemmas 1-3 veined (Chloridoideae: Muhlenbergia)"	Cynodonteae
13	"Lemmas unawned, flabellate or with veins excurrent into (5)7-15 teeth"	14
13	"Lemmas awned or unawned, lanceolate, rectangular, or ovate, veins not excurrent, forming 0-4 teeth"	15
14	"Plants viscid annuals; ligules absent (Chloridoideae, in part)"	Orcuttieae
14	"Plants not viscid, usually perennial; ligules present, composed of hairs (Chloridoideae)"	Pappophoreae
15	"Cauline leaf sheaths closed for 1/2 their length or more; glumes exceeded by the distal florets, sometimes greatly so"	16
15	"Cauline leaf sheaths open for at least 1/2 their length; glumes sometimes exceeding or exceeded by the distal florets"	18
16	"Spikelets 5-80 mm long, never viviparous; lemmas usually awned, often bilobed or bifid; lemma veins 5-13, convergent distally; ovaries pubescent distally (Pooideae, in part)"	"Bromeae {Bromus}"
16	"Spikelets 0.7-60 mm long, sometimes viviparous; lemmas often unawned, not bilobed or bifid; lemma veins sometimes parallel distally; ovaries usually glabrous distally"	17
17	"Lemma veins (4)5-13, usually prominent, parallel distally; spikelets 2.5-60 mm, not viviparous (Pooideae)"	Meliceae
17	"Lemmas veins 1-9, often inconspicuous, usually convergent distally; spikelets 0.7-18(20) mm, sometimes viviparous (Pooideae)"	Poeae
18	"Spikelets with 1 floret; lemmas terminally awned, the junction of the awn and lemma evident; rachillas not prolonged beyond the base of the floret (Pooideae)"	Stipeae
18	"Spikelets with 1-60 florets, if 1 the lemma unawned or the junction of the lemma and the awn not clearly evident; rachillas often prolonged beyond the base of the distal floret"	19
19	"Ligules of the flag leaves of hairs or a ridge or short membrane bearing cilia longer than the ridge or membrane; basal leaves usually with hairs on either side of the ligule; auricles absent"	20
19	"Ligules membranous, if ciliate, the cilia shorter than the basal membrane; leaves usually glabrous on either side of the ligule; auricles present or absent"	22
20	"Lemmas of the fertile florets with 3-11 inconspicuous veins, never glabrous, if with 3 veins, pilose throughout or with transverse tufts of hairs, if with 5-11 veins, the margins pilose towards the base, the hairs not pappillose-based; lemma apices usually bilobed or bifid and awned or mucronate from the sinus; awns, if geniculate, twisted on the basal segment"	"Danthonioideae {Danthonieae}"
20	"Lemmas of the fertile florets usually with 1-3, usually conspicuous, veins; often glabrous throughout or hairy over the veins, sometimes the margins with papillose-based hairs; lemma apices acute to obtuse, bilobed or 4-lobed, often mucronated or awned from the sinuses; awns usually not twisted"	21
21	"Lemmas of the fertile florets 1-11-veined, veins glabrous or hairy, margins without papillose-based hairs; rachillas and calluses no pilose, sometimes strigulose or strigose; basal internodes of the culms not swollen and clavate (Chloridoideae)"	Cynodonteae
21	"Lemmas of the fertile florets 3(5)-veined, veins glabrous, margins sometimes with papillose-based hairs; rachillas or calluses pilose or the basal internoes of the culms persistent, often swollen and club-shaped (Arundinoideae, in part)"	Arundineae
22	"Inflorescences panicles or unilateral racemes, neither spikelike nor with spikelike branches; spikelets solitary, the lowest (0)1-4 florets in a spikelet sterile or staminate, the distal florets sexual"	23
22	"Inflorescences panicles, racemes, or spikelike, panicles sometimes with spikelike branches; spikelets sometimes in pairs or triplets; sterile florets, if any, distal to the bisexual or pistillate florets"	26
23	"Spikelets with (1)2-25 bisexual florets; all lemmas similar in size and shape; glumes and lemmas membranous"	24
23	"Spikelets with 1 bisexual or unisexual floret; lemmas of the sterile florets usually differing in size and shape from those of the sexual floret; glumes membranous; lemmas of sexual florets stiffer than those of the sterile florets"	25
24	"Culms 35-150 cm tall; spikelets with (2)3-26 florets (including the lowest (0)1-4 sterile or staminate florets); lower glumes (1)2-9-veined (Panicoideae, in part)"	"Centotheceae {Chasmanthium}"
24	"Culms 150-400 cm tall; spikelets with 2-4 florets including the lowest sterile floret); lower glumes 0-1-veined (Panicoideae, in part)"	"Thysanolaeneae {Thysanolaena latifolia}"
25	"Lemmas of the lower florets coriaceous, at least the upper glumes exceeding the sexual floret (Ehrhartoideae)"	"Ehrharteae {Ehrharta}"
25	"Lemmas of the lower florets membranous, often both much shorter than the sexual floret, sometimes subequal to it (Pooideae)"	Poeae
26	"Lemmas with 1-3 or 9-11, conspicuous veins; sheaths open; blade cross-sections with Kranz leaf anatomy; warm season grasses (Chlorioideae, part)"	Cynodonteae
26	"Lemmas with (1)3-15, often inconspicuous, veins; if lemmas with 3 conspicuous veins, the sheaths closed, otherwise sheaths open or closed; blade cross sections without Kranz leaf anatomy; primarily cool season grasses"	27
27	"inflorescences spikes or spikelike; spikelets 1-5 per node, at least one spikelet sessile or subsessile"	28
27	"Inflorescences panicles, with no sessile spikelets"	30
28	"Upper glumes 1-5-veined; spikelets subsessile and solitary at the nodes; auricles absent (Pooideae)"	"Brachypodieae {Brachypodium}"
28	"Upper glumes 1-5-veined; spikelets 1-5+ per node, usually at least one sessile at each node; auricles present or absent; sometimes highly reduced branches present"	29
29	"Inflorescences with 1-5 spikelets per node, if 3, usually with 1 sessile and 2 pedicellate, if 1, the spikelets tangential to or embedded in the rachis, each with 2 glumes, the glumes facing each other; ovaries with hairy apices; auricles often present (Pooideae)"	Triticeae
29	"Inflorescences spikelike panicles with highly reduced branches or spikes with 1 spikelet per node, the spikelet radial to the rachis and all but the terminal spikelet with only1 glume or spikes with the spikelets tangential to the rachis and with two glumes lying side by side; ovaries with glabrous apices; auricles usually not present (Pooideae)"	Poeae
30	"Caryopses with a thick pericarp forming a distinct apical knob or beak at maturity; lemmas 3(5)-veined (Pooideae)"	"Diarrheneae {Diarrhena}"
30	"Caryopses usually with a thin pericarp, never with a distinct apical knob or beak; lemmas 3-9-veined"	31
31	"Glumes subulate, stiff; lemmas unawned or with awns tp 4 mm long (Pooideae)"	Triticeae
31	"Glumes lanceolate, not stiff, the apices rounded to acute or acuminate, sometimes awned, awns often longer than 4 mm"	32
32	"Rachillas hairy, hairs 2-3 mm long; lemmas coriaceous; plants established in California, sometimes cultivated as ornamentals (Pooideae)"	Stipeae
32	"Rachillas glabrous to hairy , hairs shorter than 2 mm; lemmas membrous to coriaceus; plants native, established introductions, or cultivated"	33
33	"Leaves to 2 cm wide, usually not conspicuously distichous; culms 0.01-2.75 m tall, usually less than 1 cm thick (Pooideae)"	Poeae
33	"Leaves 2-10 cm wide, often conspicuously distichous; culms 2-10(15) m tall, often more than 1 cm thick"	34
34	"Lower cauline blades disarticulating, upper cauline blades forming a flat, fan-shaped arrangement (Panicoideae)"	"Gynerieae {Gynerium sagittatum}"
34	"Lower cauline blades persistent, upper cauline blades not forming a flat, fan-shaped arrangement (Arundinoideae, in part)"	Arundineae