1,"Spikelets concealed in burrs",Cenchrus
1,"Spikelets not concealed in burrs",2
2,"Inflorescence of a group of 1-4 spikelets enclosed within the upper leaf sheaths; only styles and anthers exposed (kikuyu)",Pennisetum
2,"Inflorescence not enclosed within the leaf sheaths or, if partly so then of more than 4 spikelets",3
3,"Separate male and female or bisexual plants",4
3,"Plants all having bisexual spikelets (except Distichlis which is a low-growing plant with distichous leaves)",5
4,"Rhachis of the inflorescence branches continued beyond the spikelets as a prominent bristle; coastal dune plants",Spinifex
4,"Rhachis of the inflorescence branches not continued as a conspicuous bristle; arid area plants",Zygochloa
5,"Large reeds or bamboos 2 m or more high",6
5,"Smaller grasses usually under 1.5 m high",9
6,"True bamboos; culms woody and with many branches from each node",Phyllostachys
6,"Reeds, largely or entirely branched from at or near the base",7
7,"Glumes 3-5-veined",Cortaderia
7,"Glumes 1-veined",8
8,"Lemmas 5-9-veined, silky-hairy",Arundo
8,"Lemmas 1-veined, not hairy (hairs elsewhere may make this difficult to see)",Phragmites
9,"Inflorescence of 2 or more racemes or spikes arising from or appearing to arise from the apex of the culm",10
9,"Inflorescence a single raceme, spike or panicle or a single spikelet",22
10,"Spikelets with 1 or more awns",11
10,"Spikelets with no awns",17
11,"Spikelets arranged in pairs or threes",12
11,"Spikelets arranged singly",13
12,"One spikelet awned, one spikelet awnless",Dichanthium
12,"Both spikelets awned",Eulalia
13,"Lemma awn up to 1 mm long",14
13,"Lemma awn 3 mm or more long",15
14,"Racemes 0.5-4 cm long",Dactyloctenium
14,"Racemes 7-17 cm long",Eustachys
15,"Fertile lemma with conspicuous membranous wings",Oxychloris
15,"Fertile lemma not conspicuously winged",16
16,"Lemma laterally compressed",Chloris
16,"Lemma dorsally compressed",Enteropogon
17,"Bisexual floret single; lemmas 1 or 2",18
17,"Bisexual florets 2-7; lemmas 3 or more",21
18,"Spikelets with one bisexual lemma only",19
18,"Spikelets with one bisexual floret and one sterile floret below it",20
19,"Glumes longer than the lemma; lemma with a ring of hairs below the apex (sometimes difficult to see)",Brachyachne
19,"Glumes shorter than the lemma; lemma glabrous except along the keel",Cynodon
20,"Lemma margins relatively thin and lying flat on the palea",Digitaria
20,"Lemma margins relatively thick and the very edges turned in",Paspalum
21,"Lemmas 3-4.5 mm long",Eleusine
21,"Lemmas 1.5-2 mm long",Leptochloa
22,"Inflorescence a raceme, spike (make sure that there are no short branches with a few spikelets and therefore a panicle) or a single spikelet",23
22,"Inflorescence a panicle (sometimes with short branches with a few spikelets and therefore looking spike-like)",74
23,"Spikelets (at least the fertile ones) with 1 or more awns",24
23,"Spikelets (at least the fertile ones) with no awns",52
24,"Lemmas 1 or 2 in each spikelet",25
24,"Lemmas 3 or more in each spikelet",36
25,"Spikelets with 1 lemma",26
25,"Spikelets with 2 lemmas (not necessarily both fertile)",31
26,"Spikelets reflexed",Perotis
26,"Spikelets not reflexed (usually more or less erect)",27
27,"Glumes awned; lemma awnless",Zoysia
27,"Glumes awnless; lemma awned",28
28,"Awn rising obviously from the back of the lemma",Alopecurus
28,"Awn terminal, sometimes from within a sinus in the apex of the lemma",29
29,"Lemma an obviously flat structure; awn from within a sinus in the apex of the lemma",Psilurus
29,"Lemma tightly curled to form an apparently solid structure; awn terminal",30
30,"Lemma with short erect hairs at the apex and/or with short hairs on the body of the lemma",Austrostipa
30,"Lemma with a conspicuous spreading whorl of long hairs towards the apex",Jarava
31,"Lemma 3-awned",Pentaschistis
31,"Lemma and glumes each with 0 or 1 awn",32
32,"Lemma with an awn arising in a sinus in the apex of the lemma; sterile spikelets with many awnless lemmas also present",Lamarckia
32,"Lemma and glumes unawned or tapering into an awn; sterile spikelets absent",33
33,"Lemmas conspicuously awned; glumes with an inconspicuous awn or awnless",34
33,"Lemmas not awned; glumes awned",35
34,"Leaf auricles absent or inconspicuous; glume awns shorter than the body of the glumes or 0",Secale
34,"Leaf auricles well developed; glume awns at least as long as the body of the glumes",Taeniatherum
35,"Glumes glabrous; glume awn often hooked at the apex",Hemarthria
35,"Glumes hairy, often especially along the margins; glume awn not hooked",Neurachne
36,"Lemma awn distinctly arising on the back of the lemma",Gaudinia
36,"Lemma tapering into the awn or the awn arising between teeth or lobes",37
37,"Lemma apex entire, often tapering into the awn",38
37,"Lemma apex deeply or shallowly lobed, notched or toothed",46
38,"Spikelets pedicellate, sometimes shortly so",39
38,"Spikelets sessile",42
39,"Lemmas all similar (possibly decreasing slightly in size towards the apex)",40
39,"The lowest 2 lemmas sterile and distinctly different from the fertile one",41
40,"A tufted annual",Brachypodium
40,"A spreading rhizomatous perennial",Distichlis
41,"Fertile lemma awnless; glumes usually more than 2 mm long, enclosing the base of the lemmas",Ehrharta
41,"Fertile lemma shortly awned; glumes to 2 mm long, separated from the lemmas",Microlaena
42,"Spikelets arising on all sides of the rhachis forming a cylindrical spike",43
42,"Spikelets in 2 opposite rows on the rhachis forming a flattened spike",44
43,"Perennial; leaf auricles absent",Tribolium
43,"Annual; leaf auricles present",Triticum
44,"Spikelets with their single glume away from the rhachis (terminal spikelet with 2 glumes)",Lolium
44,"Spikelets with their sides against the rhachis; glumes 2",45
45,"Tufted plants without rhizomes but sometimes stoloniferous",Elymus
45,"Tufted plants with extensive rhizomes",Elytrigia
46,"Spikelets sessile or subsessile",47
46,"Spikelets distinctly pedicellate",49
47,"Lateral lobes drawn out into a point, sometimes awned",Astrebla
47,"Lateral lobes short and rounded",48
48,"Spikelets side on to the rhachis",Thinopyrum
48,"Spikelets with one glume towards and one away from the rhachis",Tripogon
49,"Lower sheaths woolly around the more or less swollen base of the plant",Monachather
49,"Lower sheaths not woolly",50
50,"Lemma 1-awned",Bromus
50,"Lemmas distinctly 3-awned",51
51,"Callus more than twice the length of the internode of the spikelet axis",Austrodanthonia
51,"Callus up to twice the length of the internode of the spikelet axis",Notodanthonia
52,"Lemma single",53
52,"Lemmas 2 or more",55
53,"Glumes 2",Parapholis
53,"Glume single",54
54,"Spikelets 4.5-7 mm long",Hainardia
54,"Spikelets 2.3-3.5 mm long",Zoysia
55,"Separate male and female plants; leaves strongly distichous",Distichlis
55,"All plants with bisexual spikelets; leaves usually basal or spreading from all sides of the culm",56
56,"Spikelets all distinctly pedicellate (the pedicels at least one-quarter of the length of the spikelet)",57
56,"Spikelets sessile or almost so",63
57,"Spikelets with 1 bisexual floret",58
57,"Spikelets with 2 or more bisexual florets",60
58,"1 sterile lemma below the fertile one",Digitaria
58,"2 sterile lemmas below the fertile one",59
59,"2nd lemma conspicuously corrugated",Ehrharta
59,"Lemmas not corrugated",Tetrarrhena
60,"Leaf sheaths fused to form a cylinder",Glyceria
60,"Leaf sheaths margins overlapping but free of one another to their bases",61
61,"Lemmas entire; glumes conspicuously cordate",Briza
61,"Lemmas 2- or 3-lobed (sometimes shallowly so) at the apex; glumes not cordate",62
62,"Leaf blades soft, flat",Bromus
62,"Leaf blades firm, tightly rolled and pungent",Triodia
63,"Spikelets side on to the rhachis",64
63,"Spikelets with one glume towards and one away from the rhachis",66
64,"Tufted annual; glumes more or less keeled",Triticum
64,"Rhizomatous perennials; glumes rounded on their backs",65
65,"Rhachis never disarticulating, scabrid",Elytrigia
65,"Rhachis disarticulating below the spikelets (sometimes at a late stage), glabrous",Thinopyrum
66,"Spikelets with 1 bisexual floret",67
66,"Spikelets with 2 or more bisexual florets",71
67,"Spikelets articulated above the glumes",68
67,"Spikelets articulated below the glumes",69
68,"Inflorescence a compact spike",Stenotaphrum
68,"Inflorescence a raceme",Tetrarrhena
69,"First glume with a hyaline window in the lower part",Thyridolepis
69,"First glume variously thickened but without a hyaline window",70
70,"Glumes similar to one another; second lemma entirely membranous or hyaline",Neurachne
70,"First glume thin, second hardened and inconspicuously veined below; second lemma cartilaginous below",Paraneurachne
71,"Spike subtended by a leaf that exceeds it in length",Tribolium
71,"Spike not subtended by a leaf",72
72,"Spikelets (except the terminal one) with a single glume",Lolium
72,"Spikelets all with 2 glumes",73
73,"Spikelets paired at each node",Hemarthria
73,"Spikelets single at each node",Pholiurus
74,"Spikelets (at least the fertile ones) with 1 or more awns",75
74,"Spikelets (at least the fertile ones) with no awns",146
75,"Lemma single in each spikelet",76
75,"Lemmas 2 or more in each spikelet",96
76,"Awn 3-branched, with or without a common column below the branches",Aristida
76,"Awns simple, although sometimes more than 1 from each lemma",77
77,"Lemma 3-5-lobed or toothed, awned",78
77,"Lemma entire or 2-lobed, often awnless",81
78,"Lemma 5-lobed or toothed",79
78,"Lemma 3-lobed",80
79,"Lemma apex toothed",Gastridium
79,"Lemma 5-lobed",Pentapogon
80,"All 3 lobes ending in awns",Amphipogon
80,"Only the central awn with an awn",Echinopogon
81,"Articulation of the spikelets below the glumes",82
81,"Articulation of the spikelets above the glumes",84
82,"Glumes awnless, 3-veined",Alopecurus
82,"Glumes awned, 1- or 3-veined",83
83,"Glumes 3-veined",Phleum
83,"Glumes 1-veined",Polypogon
84,"Glumes and lemmas both awned",85
84,"Glumes not awned",86
85,"Glumes and their awns shortly hairy or scabrid",Agropogon
85,"Glumes and their awns long-hairy",Lagurus
86,"Lemma with a straight or somewhat bent but not twisted awn",87
86,"Lemma with a bent and twisted awn",91
87,"Awn dorsal",Agrostis
87,"Awn terminal or subterminal",88
88,"Spikelets in groups of 3",Hordeum
88,"Spikelets arising singly along the rhachis",89
89,"Leaf blades tightly rolled and rigid",Ammophila
89,"Leaf blades flat or loosely rolled",90
90,"Glumes 4.5-9 mm long",Nassella
90,"Glumes 2-4 mm long",Piptatherum
91,"Lemma awn apparently terminal from the tightly rolled lemma",92
91,"Lemma awn dorsal, although sometimes from close to the apex of the more loosely rolled lemma",94
92,"Lemma with a conspicuous whorl of long spreading hairs towards the apex",Jarava
92,"Lemma with short erect hairs at the apex and/or with short hairs on the body of the lemma",93
93,"Hairs at apex of lemma absent or free",Austrostipa
93,"Hairs at apex of lemma fused to form a corona",Nassella
94,"Awn arising at or near the apex of the lemma",Dichelachne
94,"Awn arising near or below the middle of the lemma",95
95,"Lemma broad, often truncate, membranous",Lachnagrostis
95,"Lemma narrower, more or less acute, hardened",Deyeuxia
96,"Bisexual floret single in each spikelet",97
96,"Bisexual florets 2 or more in each spikelet",117
97,"Inflorescence comprising both bisexual and male or sterile spikelets",98
97,"Inflorescence of bisexual spikelets only",105
98,"Spikelets arranged singly along the rhachis; 1st lemma of bisexual spikelets bisexual",Lamarckia
98,"Spikelets in groups of 2 or 3 along and/or terminating the rhachis; 1st lemma of bisexual spikelets sterile or male",99
99,"Spikelets in threes (1 bisexual and 2 male or sterile) surrounded by 4 more male or sterile spikelets",100
99,"Spikelets in pairs or threes (1 bisexual and 1 or 2 male or sterile) without further sterile spikelets surrounding them",101
100,"Culms usually less than 50 cm high; all spikelets falling together",Iseilema
100,"Culms usually more than 50 cm high; the whorl of 4 male or sterile spikelets remaining on the plant when the group of three including the spikelet is shed",Themeda
101,"Racemes in pairs at the end of short branches, with a spathe or a long sheathing bract permanently supporting each pair",102
101,"Racemes not in pairs supported by a common spathe",103
102,"Awn glabrous",Cymbopogon
102,"Awn hairy especially on the lower part",Hyparrhenia
103,"Spikelets in threes at the ends of slender branches",Chrysopogon
103,"Spikelets predominantly in pairs along the branches",104
104,"Glumes of bisexual spikelets 2-keeled, often pitted",Bothriochloa
104,"Glumes of bisexual spikelets not keeled or pitted",Sorghum
105,"Sterile or male lemmas 1 or more, above the bisexual floret(s)",106
105,"Sterile or male lemmas below the bisexual floret",107
106,"Lemma with about 9 stiff plumose awns",Enneapogon
106,"Lemma with 1 slender awn",Holcus
107,"Two sterile or male lemmas below the single bisexual lemma",108
107,"One sterile or male lemma below the single bisexual lemma",110
108,"Inflorescence a dense spike-like panicle; plant sweetly scented",Anthoxanthum
108,"Inflorescence an open panicle; plant not scented",109
109,"Fertile lemma awnless; glumes enclosing the base of the lemmas",Ehrharta
109,"Fertile lemma shortly awned; glumes to 2 mm long and separated from the lemmas",Microlaena
110,"2nd glume awned",Melinis
110,"Glumes awnless",111
111,"1st lemma with a geniculate awn from below the middle of its back",Arrhenatherum
111,"Awns terminal or subterminal",112
112,"Spikelets in pairs; awns with a twisted column",Miscanthus
112,"Spikelets single at each node; awns more or less straight and not twisted",113
113,"2nd glume towards the rhachis",Urochloa
113,"2nd glume away from the rhachis",114
114,"1st glume vestigial or 0",Eriochloa
114,"1st glume often small but always clearly visible",115
115,"Spikelets articulated above the glumes",Echinochloa
115,"Spikelets articulated below the glumes",116
116,"Awn terminating the 2nd lemma",Brachiaria
116,"Glumes tapering into awns; lemmas awnless",Neurachne
117,"Bisexual florets 2 in each spikelet",118
117,"Bisexual florets 3 or more in each spikelet",125
118,"Awn dorsal",119
118,"Awn terminal or subterminal",121
119,"Glumes more than 15 mm long",Avena
119,"Glumes less than 10 mm long",120
120,"Annuals; lemmas without an extension of the rhachilla",Aira
120,"Perennials; lemmas with an extension of the rhachilla",Deschampsia
121,"Lemmas with about 9 terminal plumose awns",Enneapogon
121,"Lemmas with a single glabrous, scabrid or shortly hairy awn",122
122,"Fertile spikelets accompanied by conspicuous sterile spikelets",Cynosurus
122,"Spikelets all similar and fertile",123
123,"Glumes 7-11-veined",Eriachne
123,"Glumes 1-3-veined",124
124,"Lemmas with a single awn",Dactylis
124,"Lemmas with a terminal and 2 lateral awns",Pentaschistis
125,"Lemma apex entire",126
125,"Lemma apex 2- or 3-lobed or notched (sometimes very shallowly so)",133
126,"Spikelets sessile in a terminal spike-like panicle composed of globular clusters of spikelets",Elytrophorus
126,"Spikelets in a loose panicle or, if the panicle is spike-like, spikelets pedicellate",127
127,"Lemmas rounded on the back at least in the lower part",128
127,"Lemmas keeled on the back by a prominent midrib",130
128,"Annuals; awn longer than the lemma",Vulpia
128,"Perennials; awn usually shorter than the lemma",129
129,"Lemma acute; glumes keeled",Festuca
129,"Lemma obtuse; glumes rounded on their backs or with a prominent midrib",Puccinellia
130,"2nd glume 1-veined",Leptochloa
130,"2nd glume 3-9-veined",131
131,"Separate male and female plants; rhizomatous perennials; leaves in 2 rows",Distichlis
131,"Plants all bisexual; rhizomes absent, annuals or perennials; leaves basal or arising from all sides of the culm",132
132,"Annual; lemmas at least 6 mm long; 1st glume shorter than the 2nd",Bromus
132,"Perennial; lemmas 2-5 mm long; glumes subequal in length",Tribolium
133,"Lemma with a dorsal awn",134
133,"Lemma midrib extending through the apex into the awn",136
134,"Glumes enclosing the lemmas",Avena
134,"Glumes shorter than the lemmas",135
135,"Leaf sheaths fused to form a cylinder",Bromus
135,"Leaf sheaths margins overlapping but free of one another to their bases",Amphibromus
136,"Fertile spikelets accompanied by conspicuous sterile spikelets",Cynosurus
136,"Spikelets all similar and fertile",137
137,"Lemmas each with 3 awns",138
137,"Lemmas each with 1 awn",142
138,"Leaves tightly rolled, rigid, pungent",Triodia
138,"Leaves flat or loosely rolled, relatively soft",139
139,"Central awn arising from a long central lobe of the lemma",Triraphis
139,"Central awn arising from the sinus between the 2 lobes of the lemma",140
140,"Callus more than twice the length of the internode of the spikelet axis",Austrodanthonia
140,"Callus up to twice the length of the internode of the spikelet axis",141
141,"Upper row of lemma hair tufts absent",Joycea
141,"Upper row of lemma hair tufts present",Notodanthonia
142,"Awn strongly bent and twisted; basal of plant woolly",Monachather
142,"Awn straight or slightly bent; base of plant not woolly",143
143,"Leaves tightly rolled, rigid, pungent",Triodia
143,"Leaves flat or loosely rolled, relatively soft",144
144,"1st glume less than half as long as the 2nd glume",Avellinia
144,"1st glume more than half as long as the 2nd glume",145
145,"Awn to 1 mm long; 2nd glume usually much shorter than the 1ast lemma",Leptochloa
145,"Awn 1-5.5 mm long; 2nd glume nearly as long as the 1st lemma",Rostraria
146,"Lemma single in each spikelet",147
146,"Lemmas 2 or more in each spikelet (see Paspalum in which the total loss of 1 glume may lead to the first lemma being mistaken for the second glume)",153
147,"Spikelets furnished with hooked spines",Tragus
147,"Spikelets without spines",148
148,"Articulations above the glumes",149
148,"Articulation below the glumes",152
149,"1st glume distinctly shorter than the lemma",Sporobolus
149,"1st glume about as long as or longer than the lemma",150
150,"Panicle spike-like; leaves tightly rolled and rigid",Ammophila
150,"Panicle more or less open; leaves flat or loosely rolled and moderately soft",151
151,"Rhachilla not extended beyond the lemma or less than one-fifth of the lemma length; inflorescence remaining attached to the plant",Agrostis
151,"Rhachilla usually at least one-third of the length of the lemma; inflorescence usually separating from the plant at maturity of the fruits",Lachnagrostis
152,"Glumes 1-3.5 mm long; inflorescence a more or less dense spike-like panicle",Polypogon
152,"Glumes 8-18 mm long; inflorescence a number of spike-like racemes",Spartina
153,"Bisexual floret 1 per spikelet",154
153,"Bisexual florets 2 or more per spikelet",183
154,"Stiff and often scabrid or hairy bristles on the inflorescence axis below some or all spikelets or with a bristle terminating the rhachis",155
154,"Bristles not present, but often the inflorescence axes softly or shortly hairy",163
155,"At least 1 bristle at the base of every spikelet",156
155,"Bristles along each rhachis (not directly associated with individual spikelets), at the base of the terminal spikelet, or terminating the rhachis",158
156,"Bristles persisting on the inflorescence when the spikelets are shed",Setaria
156,"Bristles falling with the spikelets or the branchlets when these are shed",157
157,"Panicle branches disarticulating at their bases, falling off with the spikelets",Paractaenum
157,"Panicle usually spike-like; bristles shed with each spikelet",Pennisetum
158,"A single bristle at the base of the terminal spikelet on each branch or terminating the rhachis",159
158,"Bristles not restricted to 1 at the base of terminal spikelets",161
159,"2nd glume truncate; spikelets 8-12 mm long",Uranthoecium
159,"2nd glume acute; spikelets 2-8 mm long",160
160,"2nd glume tapering to a long point; spikelets 3-8 mm long",Pseudoraphis
160,"2nd glume more or less acute, not tapering; spikelets 2-4 mm long",Setaria
161,"Panicle branches disarticulating at their bases, falling off with the spikelets",Paractaenum
161,"Panicle branches persisting on the plant",162
162,"Bristles in the form of coarse hairs along the rhachis of the branches",Echinochloa
162,"Bristle terminating the rhachis of the branches",Setaria
163,"Panicle spike-like",164
163,"Panicle open or with conspicuous branches",168
164,"Spikelets sunk in notches in the flat rhachis",Stenotaphrum
164,"Spikelets not sunk in notches in the rhachis",165
165,"Glumes densely long-hairy",Imperata
165,"Glumes glabrous, shortly hairy or with localised long hairs",166
166,"Glumes winged, scabrid or shortly hairy on the keels",Phalaris
166,"Glumes not winged or keeled, long-ciliate on the margins",167
167,"Glumes similar to one another; second lemma entirely membranous or hyaline",Neurachne
167,"First glume thin, second hardened and inconspicuously veined below; second lemma cartilaginous below",Paraneurachne
168,"Sterile lemmas 2 or 3",169
168,"Sterile lemma 1",171
169,"2nd lemma conspicuously corrugated",Ehrharta
169,"Lemmas not corrugated",170
170,"Sterile lemmas above the bisexual floret",Melica
170,"Sterile lemmas below the bisexual floret",Tetrarrhena
171,"Sterile lemma above the bisexual floret",Eustachys
171,"Sterile lemma below the bisexual floret",172
172,"Glumes subequal in length",Isachne
172,"1st glume 0 or distinctly smaller than the 2nd glume",173
173,"Spikelets in pairs; 1 sessile and bisexual, 1 pedicellate and sterile",Sorghum
173,"Spikelets solitary or in groups but all bisexual",174
174,"1st glume absent or rarely to 2 mm long",175
174,"Glumes both well developed and usually more than 2 mm long",177
175,"Spikelets with a disk-like swelling below the glume",Eriochloa
175,"Spikelets without a spike-like swelling below the glumes",176
176,"1st lemma towards the rhachis",Axonopus
176,"1st lemma away from the rhachis",Paspalum
177,"Inflorescence branches not forming well defined spikes or racemes",178
177,"Inflorescence branches forming well defined spikes or racemes",181
178,"Spikelets in twos or threes",Digitaria
178,"Spikelets single at each node",179
179,"1st glume distinctly more than half the length of the spikelet; leaves glabrous",Walwhalleya
179,"1st glume less than half the length of the spikelet; if about half the length then the leaves more or less hairy",180
180,"Inflorescence 4-40 cm long; rhachilla short between the glumes",Panicum
180,"Inflorescence 1.5-3.5 cm long; rhachilla elongated between the glumes",Yakirra
181,"Bisexual lemma with flat translucent margins which are thinner than and pressed against the body of the lemma",Digitaria
181,"Bisexual lemma with narrowly rolled margins of the same texture as the body of the lemma",182
182,"1st glume towards the rhachis",Brachiaria
182,"1st glume away from the rhachis",Echinochloa
183,"Lemma 3-lobed or notched or toothed",184
183,"Lemma apex entire",192
184,"Leaves rounded in section, rigid and pungent; spikelets 5-30 mm long",Triodia
184,"Leaves flat or rolled, if slightly pungent the spikelets not more than 5 mm long",185
185,"Lemmas 2, apically several-toothed",Molineriella
185,"Lemmas 3 or more, mostly with a single apical notch",186
186,"Lemmas 10-22 mm long",187
186,"Lemmas 1.8-6 mm long",188
187,"Glumes enclosing the rest of the spikelet",Avena
187,"Lemmas extending well beyond the glumes",Bromus
188,"Lemma usually rounded on the back, strongly hairy towards the margins",Leptochloa
188,"Lemma keeled as a result of a prominent midrib, not strongly hairy towards the margins",189
189,"Glumes distinctly longer than the individual lemmas",Schismus
189,"Glumes shorter than or about as long as the individual lemmas",190
190,"Lemmas 1.5-2.5 mm long",Puccinellia
190,"Lemmas 3.5-6 mm long",191
191,"Inflorescence open and sparse; lemmas usually hairy especially on veins and margins",Poa
191,"Inflorescence contracted and dense; lemmas glabrous",Sclerochloa
192,"Plants either male or female; occurs in wet, especially saline, habitats and has obviously 2-ranked leaves",Distichlis
192,"Plants all bisexual; habitat various; leaves not obviously 2-ranked",193
193,"Lemmas rounded on their back at least for much of their lower part",194
193,"Lemmas keeled on their back as a result of at least one prominent midrib",203
194,"Lemmas 2, thick and hard; spikelets dorsally compressed",Isachne
194,"Lemmas usually 3 or more, if only 2 then not thick and hard and spikelets laterally compressed",195
195,"Lemmas 2; glumes 5-10 mm long",Eriachne
195,"Lemmas usually 3 or more, if only 2 then at least 15 mm long",196
196,"Glumes 16-33 mm long",Avena
196,"Glumes up to 9 mm long",197
197,"Glumes conspicuously different in length",198
197,"Glumes equal or subequal in length",202
198,"Lemmas 3-veined",Leptochloa
198,"Lemmas 5-7-veined",199
199,"Lemmas more or less obtuse, 5-veined",Puccinellia
199,"Lemmas acute or, if somewhat obtuse, then 7-veined",200
200,"Lemmas 3-veined; glumes 1-veined",Leptochloa
200,"Lemmas 5-7-veined; glumes 1-5-veined",201
201,"Leaf sheaths fused to form a cylinder",Glyceria
201,"Leaf sheath margins overlapping, not fused",Festuca
202,"Glumes about as long as wide",Briza
202,"Glumes several times as long as wide",Catapodium
203,"Spikelets sessile, in distinct spikes",Eleusine
203,"Spikelets pedicellate or, if shortly pedicellate, not in distinct spikes",204
204,"Glumes 9-14 mm long",Austrofestuca
204,"Glumes up to 8 mm long",205
205,"Ligule a membrane or ridge",206
205,"Ligule of hairs or a hair-fringed membrane",209
206,"Rhachilla not articulated; glumes not keeled",Sclerochloa
206,"Rhachilla articulated below each lemma or, if not articulated, the glumes keeled",207
207,"1st glume c. 0.2 mm long, rounded on its back",Sphenopus
207,"1st glume at least 0.7 mm long, keeled",208
208,"Spikelets in compact clusters",Dactylis
208,"Spikelets evenly spread through the inflorescence",Poa
209,"Lemmas 2 in each spikelet",Eriachne
209,"Lemmas 3 or more in each spikelet",210
210,"Spike subtended by a leaf that exceeds it in length",Tribolium
210,"Spike not subtended by a leaf",Eragrostis