1	"Leaves spirally arranged"	Micraira
1	"Leaves arranged in two rows"	2
2	"Spikelets morphologically or functionally unisexual"	3
2	"Spikelets bisexual"	9
3	"Spikelets with 1 floret, or more than 2 florets"	4
3	"Spikelets with 2 florets"	5
4	"Short grasses with a compact raceme"	"Distichlis: Distichlis distichophylla"
4	"Tall reed-like grasses with a plumose panicle"	"Cortaderia: Cortaderia selloana"
5	"Upper lemma membranous, thinner than glumes"	6
5	"Upper lemma hardened, thicker than glumes"	7
6	"Inflorescence consisting of a female spikelet enclosed in a rigid shell, from which a raceme of male spikelets emerges apically"	"Coix: Coix lacryma-jobi"
6	"Inflorescence spike-like with female spikelets basal and male apical"	Polytoca
7	"Plants monoecious, i.e. with male and female spikelets on the same plant"	"Hygrochloa: Hygrochloa aquatica"
7	"Plants dioecious i.e. with male and female spikelets on different plants"	8
8	"Inflorescence a contracted, spike-like panicle, not spatheate"	Cenchrus
8	"Inflorescences clustered together in dense, umbel-like spatheate heads"	Spinifex
9	"Spikelets with 1 to many florets, if 2-flowered both florets or lower one bisexual"	10
9	"Spikelets 2-flowered, lower floret male or barren, upper bisexual or female"	106
10	"Inflorescence a solitary bilateral spike or raceme; spikelets usually with the broad side facing the axis"	11
10	"Inflorescence a panicle or a unilateral or multilateral spike or raceme, rarely a bilateral spike but then the spikelets edgewise on to the axis"	20
11	"Lemmas 3-5-nerved, hyaline to membranous"	12
11	"Lemmas 5-10-nerved, hardened at maturity"	14
12	"Spikelets compressed laterally"	"Parapholis: Parapholis incurva"
12	"Spikelets compressed dorsiventrally"	13
13	"Lemmas with lateral nerves extending to the apex"	Lepturus
13	"Lemmas with very short lateral nerves"	"Hainardia: Hainardia cylindrica"
14	"Rachilla terminated by a fertile floret"	"Tetrarrhena: Tetrarrhena laevis"
14	"Rachilla prolonged beyond the uppermost fertile floret"	15
15	"Spikelets in groups of more than 2 at each rachis node"	Hordeum
15	"Spikelets solitary at each rachis node"	16
16	Annuals	17
16	Perennials	19
17	"Glumes not keeled"	"Brachypodium: Brachypodium distachyon"
17	"Glumes strongly keeled"	18
18	"Glumes subulate"	"Secale: Secale cereale"
18	"Glumes not subulate"	"Triticum: Triticum aestivum"
19	"Plant with long creeping rhizomes"	"Elytrigia: Elytrigia repens"
19	"Plant tufted, or with short rhizomes"	Anthosachne
20	"Fertile lemmas deeply or distinctly lobed"	21
20	"Fertile lemmas entire, dentate or slightly lobed"	24
21	"Spikelets 1-flowered"	Amphipogon
21	"Spikelets 2-or more-flowered, rarely 1-flowered"	22
22	"Lemmas 9-lobed"	Enneapogon
22	"Lemmas 3-lobed"	23
23	"Inflorescence a 1-sided raceme"	Astrebla
23	"Inflorescence a panicle or spike"	Triodia
24	"Leaf blades hard, woody, needle-like"	Triodia
24	"Leaf blades not hard, woody, needle-like"	25
25	"Tall reed-like plants"	26
25	"Plants not tall and reed-like"	27
26	"Lemmas hairy; rachilla not hairy"	"Arundo: Arundo donax"
26	"Lemmas not hairy; rachilla hairy"	Phragmites
27	"Spikelets with 2 or more bisexual florets or if only one, with rachilla extension or sterile florets (empty lemmas) above it"	28
27	"Spikelets with 1 bisexual floret, with or without male or sterile florets (empty lemmas) below it"	81
28	"Spikelets with 2 florets, without a rachilla extension"	Rytidosperma
28	"Spikelets with 3 or more florets or with 1or 2 florets and a rachilla extended beyond the upper floret"	29
29	"Inflorescence racemose or spicate, or digitate or non-digitate"	30
29	"Inflorescence a panicle"	44
30	"Inflorescence digitate or subdigitate"	31
30	"Inflorescence racemose or spicate"	39
31	"Spikelet with at least 3 fertile florets"	32
31	"Spikelet with 1 (rarely 2) fertile florets"	35
32	"Axis of each inflorescence branch ending in a bristle; spikelet-bearing axis disarticulating"	Dactyloctenium
32	"Axis of each inflorescence branch ending in a spikelet; spikelet-bearing axis not disarticulating"	33
33	"Spikelets 2-5; lemma 5-7-nerved; leaves mostly basal, setaceous"	"Cyperochloa: Cyperochloa hirsuta"
33	"Spikelets many; lemma 3-nerved; leaves not basally aggregated or setaceous"	34
34	"Lemmas mucronate to shortly awned; upper glume 1-nerved"	"Acrachne: Acrachne racemosa"
34	"Lemmas muticous; upper glumes 3-7-nerved"	Eleusine
35	"Spikelet with 1 floret; lemmas unawned"	Cynodon
35	"Spikelet with 2 or more florets; lemmas awned"	36
36	"Lowest lemma dorsally compressed (lying on front or back when placed on a flat surface)"	Enteropogon
36	"Lowest lemma laterally compressed (lying on the side when placed on a flat surface)"	37
37	"Inflorescence with more than 40 branches"	"Eustachys: Eustachys distichophylla"
37	"Inflorescence with less than 20 branches"	38
38	"Lemmas very broad, wing-like"	"Oxychloris: Oxychloris scariosa"
38	"Lemmas not very broad, not wing-like"	Chloris
39	"Spikelets unilateral (borne on one side of the inflorescence axis)"	40
39	"Spikelets bilateral or multilateral (borne on opposite sides or all round the inflorescence axis)"	42
40	"Spikelet with one fertile floret"	Lolium
40	"Spikelet with many fertile florets"	41
41	"Lower glume 5-nerved; lemma 7-nerved"	Tribolium
41	"Lower glume 1-nerved; lemma 1-3-nerved"	"Tripogonella: Tripogonella loliiformis"
42	"Spikelets falling with glumes; rachilla terminated by a floret"	"Tragus: Tragus australianus"
42	"Spikelets disarticulating above glumes; rachilla extending beyond upper floret"	43
43	"Lemmas awned; glumes not keeled"	Vulpia
43	"Lemmas awnless; glumes keeled"	"Catapodium: Catapodium rigidum"
44	"Glumes usually shorter than lowest floret and with the upper florets distinctly exserted; lemmas awnless or with a straight or curved awn from an entire or bifid apex, or several-awned or lobed"	45
44	"Glumes (or the longer one) at least as long as or longer than the lowest floret, often as long as the spikelet and enclosing the florets; lemmas awnless or more often awned from the back or from the sinus of a 2-lobed tip, the awn usually geniculate, rarely the awn straight or curved from the tip"	64
45	"Lemmas 1-3-nerved"	46
45	"Lemmas 5-many nerved"	53
46	"Lemmas 3-awned"	"Triraphis: Triraphis mollis"
46	"Lemmas 1-awned or without awns"	47
47	"Lemmas notched, toothed or lobed"	48
47	"Lemmas entire"	51
48	"Spikelets borne in leaf-sheath axils"	Eragrostis
48	"Spikelets not borne in leaf-sheath axils"	49
49	"Ligule apex acute to attenuate"	"Diplachne: Diplachne fusca"
49	"Ligule apex usually trunate to obtuse"	50
50	"Panicle branches arranged in racemes along rachis; ligule apex erose or entire but never ciliate"	Dinebra
50	"Panicle branches digitate to sub-digitate inserted along the rachis usually with two or more branches per node; ligule apex ciliate"	"Leptochloa: Leptochloa digitata"
51	"Lemmas not awned"	Eragrostis
51	"Lemmas awned"	52
52	"Spikelets in globose clusters; palea winged"	"Elytrophorus: Elytrophorus spicatus"
52	"Spikelets in dense to loose panicles; palea not winged"	Eragrostis
53	"Ovary hairy at apex"	Bromus
53	"Ovary glabrous at apex"	54
54	"Spikelets dimorphous, with bisexual spikelets surrounded by sterile ones"	55
54	"Spikelets not dimorphous"	56
55	"Spikelets disarticulating above the glumes; spikelet-bearing axes persistent"	Cynosurus
55	"Spikelets disarticulating with the glumes; spikelet bearing axes disarticulating"	"Lamarckia: Lamarckia aurea"
56	"Inflorescence a contracted panicle or a panicle of racemes"	57
56	"Inflorescence an open panicle"	59
57	"Glumes very unequal"	Vulpia
57	"Glumes more or less equal"	58
58	"Leaf blades up to 3 mm long and basal, if present"	"Spartochloa: Spartochloa scirpoidea"
58	"Leaf blades well developed and not mainly basal"	"Catapodium: Catapodium rigidum"
59	"Spikelets almost as wide as long"	Briza
59	"Spikelets up to half as wide as long"	60
60	"Lemmas ± rounded or flattened on back, at least below"	61
60	"Lemmas keeled throughout"	62
61	"Lemmas 7-9-nerved; leaf sheath margins joined"	Glyceria
61	"Lemmas 5-nerved; leaf sheath margins free"	Puccinellia
62	"Leaves mostly basal; lemmas similar in texture to glumes, awnless"	Poa
62	"Leaves not basally aggregated; lemmas firmer than glumes, awned"	63
63	"Lemmas keeled; palea thinner than lemma"	"Dactylis: Dactylis glomerata"
63	"Lemmas not keeled; palea with similar texture to lemma"	Festuca
64	"Ligule membranous"	65
64	"Ligule a fringe of hairs, ciliate membrane or ciliate at margins"	71
65	"Lemmas 3-nerved"	"Avellinia: Avellinia michelii"
65	"Lemmas 5-9-nerved"	66
66	"Lower floret male"	"Arrhenatherum: Arrhenatherum elatius var. bulbosum"
66	"Lower floret bisexual"	67
67	"Glumes more than 14 mm long"	Avena
67	"Glumes less than 10 mm long"	68
68	Perennials	Amphibromus
68	Annuals	69
69	"Panicle spicate"	Rostraria
69	"Panicle open"	70
70	"Awn with a ring of hairs at junction of column and limb"	"Corynephorus: Corynephorus fasciculatus"
70	"Awn without a ring of hairs"	Aira
71	"Leaf sheaths of the lower leaves swollen and woolly or leaf blades hard, woody, needle-like"	"Monachather: Monachather paradoxus"
71	"Leaf sheaths of the lower leaves not swollen and woolly and leaf blades not hard, woody, needle-like"	72
72	"Lemmas awnless, sometimes mucronate"	73
72	"Lemmas distinctly awned"	75
73	"Lemmas entire, if mucronate, mucros apical"	Tribolium
73	"Lemmas bilobed; if mucronate, mucro is from an apical sinus"	74
74	"Grain not longitudinally grooved"	Schismus
74	"Grain longitudinally grooved"	Rytidosperma
75	"Hairs on the lemma in two untidy rows, most of lemma surface glabrous and shiny; leaves often disarticulating from sheath"	Rytidosperma
75	"Hairs on the lemma forming a continuous indumentum, sometimes with tufts on the upper margin; leaves not disarticulating"	76
76	"Lemmas neither distinctly hairy nor awned"	"Molineriella: Molineriella minuta"
76	"Lemmas either distinctly hairy or awned"	77
77	"Upper glume twice length of lower glume"	"Pheidochloa: Pheidochloa gracilis"
77	"Glumes ± equal in length"	78
78	"Glumes (3-)5-11-nerved"	Eriachne
78	"Glumes 1-3-nerved"	79
79	"Bisexual florets 1 per spikelet"	Holcus
79	"Bisexual florets 2 per spikelet"	80
80	"Lemma awn dorsal"	Aira
80	"Lemma awn terminal"	Pentameris
81	"Glumes absent or rudimentary"	82
81	"Glumes well developed"	83
82	"Spikelets 1-flowered"	"Leersia: Leersia hexandra"
82	"Spikelets 3-flowered, the lower two reduced to sterile lemmas"	Oryza
83	"Spikelets with 3 florets, the lower two reduced to sterile or male and sometime minute lemmas"	84
83	"Spikelets with 1 floret"	87
84	"Both sterile lemma with a hinge-like appendage"	Ehrharta
84	"Neither sterile lemmas with an appendage"	85
85	"Glumes minute"	"Microlaena: Microlaena stipoides var. stipoides"
85	"Glumes relatively large"	86
86	"Sterile lemmas shorter than fertile floret; glumes winged"	Phalaris
86	"Sterile lemmas longer than fertile floret; glumes not winged"	"Anthoxanthum: Anthoxanthum odoratum"
87	"Glumes much longer than lemma and with long awns"	"Perotis: Perotis rara"
87	"Glumes usually shorter than lemma and if awned only slightly so"	88
88	"Lemma terete or dorsally compressed"	89
88	"Lemma laterally compressed"	91
89	"Lemma with a 3-branched awn (very rarely 1-branched)"	Aristida
89	"Lemma with a single undivided awn"	90
90	"Awn ± geniculate; spikelet base (callus) pointed, often long and pungent"	Austrostipa
90	"Awn ± straight; spikelet base (callus) short and blunt"	"Piptatherum: Piptatherum miliaceum"
91	"Lemmas coriaceous to indurated"	92
91	"Lemmas membranous to cartilaginous"	94
92	"Lemma awns geniculate"	"Pentapogon: Pentapogon quadrifidus var. quadrifidus"
92	"Lemma awns non-geniculate"	93
93	"Lemma with a 3-branched awn (very rarely 1-branched); spikelets with one floret"	Aristida
93	"Lemma with a single awn; spikelets with 2 florets (very rarely 1)"	Eriachne
94	"Glumes similar in texture to and shorter than lemmas; ligule hairy to some degree"	Sporobolus
94	"Glumes firmer in texture to and as long as or longer than lemmas; ligule an fringeless membrane"	95
95	"Spikelets falling entire"	96
95	"Spikelets disarticulating above the glumes"	97
96	"Glumes blunt, ±united"	Alopecurus
96	"Glumes acute or awned, distinctly separate"	Polypogon
97	"Glumes swollen at base"	"Gastridium: Gastridium phleoides"
97	"Glumes not swollen at base"	98
98	"Glumes silky-woolly, much longer than lemma"	"Lagurus: Lagurus ovatus"
98	"Glumes not silky-woolly, equal to or slightly longer than lemmas"	99
99	"Spikelets at least 9 mm long"	"Ammophila: Ammophila arenaria subsp. arenaria"
99	"Spikelets up to 7 mm long"	100
100	"Glumes terminating abruptly, shortly awned"	101
100	"Glumes obtuse or acute, not or scarcely awned"	102
101	"Lemmas awned; inflorescence a contracted panicle"	Polypogon
101	"Lemmas not awned; inflorescence a tight spike-like panicle"	Phleum
102	"Glumes with regularly arranged hairs on keel"	"Echinopogon: Echinopogon ovatus"
102	"Glumes smooth to rough on keel, without hairs"	103
103	"Lemma awns more than twice as long as lemma"	Dichelachne
103	"Lemma awns, if present, less than twice as long as lemma"	104
104	"Lemmas decidedly firmer than the glumes"	Deyeuxia
104	"Lemmas less firm than the glumes"	105
105	"Inflorescence axis persistent; rachilla extension less than 20% of lemma length"	Agrostis
105	"Inflorescence often detaching as a diaspore; rachilla extension 30-100% of lemma length"	Lachnagrostis
106	"Spikelets breaking up above the glumes"	107
106	"Spikelets falling entire, breaking below the glumes"	108
107	"Glumes very unequal; spikelets compressed laterally"	"Arundinella: Arundinella nepalensis"
107	"Glumes ±equal; spikelets compressed dorsiventrally"	"Isachne: Isachne minutula"
108	"Spikelets often dissimilar and usually paired, with one sessile and the other pedicelled (occasionally both pedicelled, but unequally, or in 3's with 2 sessile and 1 pedicelled) or rarely with the pedicelled spikelet reduced to the pedicel; upper lemma of sessile spikelet usually geniculately awned; glumes firm in texture"	109
108	"Spikelets all alike and usually solitary, rarely paired; upper lemma not geniculately awned; glumes usually membranous"	134
109	"Spikelets similar in shape and size, development of awns and sex; if different pedicelled spikelets awned and sessile unawned; pedicels and raceme joints slender"	110
109	"Spikelets different in shape and size, development of awns and sex; if similar, pedicels and joints thickened"	114
110	"Paired spikelets unequally pedicelled"	111
110	"Paired spikelets with at least one sessile"	113
111	"Spikelets awnless"	"Imperata: Imperata cylindrica"
111	"Spikelets awned from apex of the upper lemma"	112
112	"Inflorescence a panicle, the racemes at least 10 cm long"	"Miscanthus: Miscanthus sinensis"
112	"Inflorescence of subdigitate racemes up to 7 cm long"	Pseudopogonatherum
113	"Sessile spikelets male; pedicelled spikelets female"	"Germainia: Germainia truncatiglumis"
113	"Sessile and pedicelled spikelets of the same sex"	Eulalia
114	"Rachis joints and pedicels thick, ± contiguous or fused together, forming cavities into which the spikelets are sunk"	115
114	"Rachis joints and pedicels slender, or if thickened upwards, not forming cavities"	120
115	"Sessile spikelet awned"	116
115	"Sessile spikelet awnless"	117
116	"Pedicels ± flat"	"Sehima: Sehima nervosum"
116	"Pedicels swollen"	Ischaemum
117	"Lower glume of sessile spikelet 2-toothed"	"Elionurus: Elionurus citreus"
117	"Lower glume of sessile spikelet not 2-toothed"	118
118	"Spikelets in opposite rows on axis"	"Ophiuros: Ophiuros exaltatus"
118	"Spikelets on one side of axis"	119
119	"Spikelets of each pair similar, both bisexual; rachis not fragmenting"	"Hemarthria: Hemarthria uncinata var. uncinata"
119	"Spikelets of each pair dissimilar, pedicelled male or sterile or spikelets borne singly; rachis fragmenting readily"	"Hackelochloa: Hackelochloa granularis"
120	"Inflorescence with spathes, spatheoles or spathe-like sheaths enclosing or subtending inflorescence"	121
120	"Inflorescences espatheate"	127
121	"Fertile spikelets ±compressed, the lower glume distinctly 2-keeled for most of its length"	122
121	"Fertile spikelets ±terete, the lower glume 2-keeled only at the tip if at all"	125
122	"Lower part of awn as wide as the lemma from which it arises"	"Spathia: Spathia neurosa"
122	"Lower part of awn narrower than the lemma from which it arises"	123
123	"Raceme bases terete"	Andropogon
123	"Raceme bases flattened"	124
124	"Racemes paired; leaves aromatic"	Cymbopogon
124	"Racemes solitary; leaves not aromatic"	Schizachyrium
125	"Fertile spikelets not within an involucre of male or barren spikelets"	Hyparrhenia
125	"Fertile spikelets within an involucre of male or barren spikelets"	126
126	"Fertile spikelets falling with involucre or whole raceme falling as one unit; callus blunt"	Iseilema
126	"Fertile spikelets falling separately from involucres; callus pungent"	Themeda
127	"Rachis joints and pedicels with a translucent mid-line between thickened margins"	128
127	"Rachis joints and pedicels without a translucent mid-line"	129
128	"Inflorescence more than once-branched"	"Capillipedium: Capillipedium parviflorum"
128	"Inflorescence an arrangement of racemes on a central axis"	Bothriochloa
129	"Inflorescence of solitary, paired or subdigitate racemes"	130
129	"Inflorescence a panicle"	131
130	"Fertile spikelet ±cylindrical in cross-section; callus pungent"	"Heteropogon: Heteropogon contortus"
130	"Fertile spikelet ±compressed; callus not pungent"	Dichanthium
131	"Spikelets laterally compressed"	Chrysopogon
131	"Spikelets dorsally compressed or ±cylindrical"	132
132	"Pedicelled spikelet reduced to pedicel; panicle axes not terminating in spikelets"	"Sorghastrum: Sorghastrum nutans"
132	"Pedicelled spikelet developed, rarely reduced or suppressed but then panicle axes terminating in spikelets"	133
133	"Lemma awns of sessile spikelet absent or 1-1.5 cm long if present"	Sorghum
133	"Lemma awns of sessile spikelet 2-9 cm long"	Sarga
134	"Inflorescence a spike or spike-like raceme or digitate pair of racemes; glumes as long as or longer than the florets"	135
134	"Inflorescence otherwise or if a spike or raceme lower glume shorter than the florets"	140
135	"Inflorescence of paired racemes (with rarely a third raceme)"	"Dimeria: Dimeria ornithopoda"
135	"Inflorescence a single spike or raceme"	136
136	"Inflorescence a spike"	Thaumastochloa
136	"Inflorescence single raceme"	137
137	"Spikelets with distinct bristles from confluent tubercles"	Thyridolepis
137	"Spikelets with indistinct bristles from single tubercles, sometimes densely hairy"	138
138	"Plant shortly rhizomatous"	Neurachne
138	"Plant stoloniferous"	139
139	Annuals	"Thedachloa: Thedachloa annua"
139	Perennials	"Paraneurachne: Paraneurachne muelleri"
140	"Spikelets with awns arising from between apical lobes of upper glume and lower lemma"	"Melinis: Melinis repens"
140	"Spikelets awnless or with awn arising terminally from lemmas or glumes"	141
141	"Spikelets in bunches subtended by bracts"	Xerochloa
141	"Spikelets not in bunches subtended by bracts"	142
142	"Inflorescence with broad, flattened axis with spikelets on one or both sides"	"Stenotaphrum: Stenotaphrum secundatum"
142	"Inflorescence otherwise"	143
143	"Inflorescence branches ending in bristle-like appendages or spikelets subtended by bristles"	144
143	"Inflorescence branches ending in spikelets which are not subtended by bristles"	148
144	"Spikelets falling at maturity without any bristles or spines attached"	145
144	"Spikelets falling at maturity with bristles or spines attached"	147
145	"Spikelets subtended by solitary bristles or an involucre of bristles"	Setaria
145	"Spikelets in racemes terminating in bristle-like appendages"	146
146	"Upper lemma covered with wrinkles, as long as or longer than upper glume"	Paspalidium
146	"Upper lemma smooth, shorter than upper glume"	"Pseudoraphis: Pseudoraphis spinescens"
147	"Spikelets completely surrounded by a ring of spines or bristles"	Cenchrus
147	"Spikelets not surrounded by spines or bristles"	Paractaenum
148	"Spikelet with a bead-like swelling at base"	Eriochloa
148	"Spikelet without a bead-like swelling at base"	149
149	"Fertile lemma less firm or similar in texture to glumes"	150
149	"Fertile lemma decidedly firmer than the glumes"	152
150	"Upper glume mucronate to shortly awned"	Alloteropsis
150	"Upper glume obtuse to acuminate, not awned or mucronate"	151
151	"Lower glume minute or absent; spikelet dorsally compressed"	Digitaria
151	"Lower glume c. 1/3 spikelet length; spikelet terete or ±laterally compressed"	Digitaria
152	"Rachilla prominent between glumes and between florets"	153
152	"Rachilla not prominent between glumes and between florets; fertile florets without appendage at base"	154
153	"Rachilla swollen beneath fertile florets and usually with lateral appendages"	Yakirra
153	"Rachilla not swollen beneath fertile florets and without lateral appendages"	Whiteochloa
154	"Inflorescence an open or contracted panicle branched more than once; spikelets not grouped along one side of ultimate branches"	155
154	"Inflorescence once branched, the branches digitate or borne on elongated axis; spikelets grouped along one side of branches"	160
155	"Glumes very unequal in length"	"Isachne: Isachne minutula"
155	"Glumes slightly unequal in length"	156
156	"Lower glume absent or represented by a minute scale"	157
156	"Lower glume present"	158
157	"Lower lemma adjacent to the inflorescence axis"	"Axonopus: Axonopus fissifolius"
157	"Lower lemma positioned away from the inflorescence axis"	Paspalum
158	"Spikelets awnless or mucronate"	Urochloa
158	"Spikelets distinctly awned"	159
159	"Glumes more or less equal and similar; decumbent grass of shaded habitats"	"Oplismenus: Oplismenus hirtellus"
159	"Glumes very unequal and dissimilar; erect grass of wet habitats"	Echinochloa
160	"Inflorescence a spike-like panicle"	Sacciolepis
160	"Inflorescence an open panicle"	161
161	"Fertile floret smooth and shiny"	Panicum
161	"Fertile floret transversely rugose"	"Megathyrsus: Megathyrsus maximus var. maximus"