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