Leaves solitary at the nodes, sometimes crowded at the base of the stem, alternate and usually in 2 rows, consisting of sheath, ligule and blade; sheath with margins free and overlapping or, rarely, more or less fused; ligule at junction of blade and sheath, membranous, a row of hairs, rarely absent; blade usually linear, rarely broad and short, flat, rolled or folded, parallel-veined.
Inflorescence compound, with spikelets arranged in open or contracted 'panicles', racemes or spikes. Spikelets of 1–many florets, distichous, sessile on a slender axis (the rachilla), subtended by 2 (rarely 1) empty bracts known as the upper and lower glumes. Flowers (florets) mostly bisexual, sometimes unisexual or sterile, usually with ovary, stamens, and 2 or 3 minute fleshy scales or lodicules sometimes interpreted as relictual perianth, the whole between 2 bracts known as the lemma (the lower bract) and palea. Stamens 1–6 but most commonly 3; stigmas usually 2, plumose.
Fruit mostly a caryopsis with the pericarp adnate, rarely a nut, berry, or an utricle.
Refs Simon (1990), Webster (1987), Wheeler, Jacobs & Norton (1982, 1990), Jacbos, Whalley & Wheeler (2008).
Grasses are of major economic importance in the form of cereal grains. They directly supply about 60% of the food for human consumption, including about 75% of carbohydrate, and 55% of protein. Grasses and cereal grains, converted to animal products, supply about 20% of our dietary protein. The principal cereals are, in order of importance, Wheat, Rice, Maize, Barley, Oats, Sorghum, Rye and several grasses usually grouped together and termed 'Millets'. Rice, grown largely in the tropics and subtropics, is the staple diet for half the world's population, while wheat is the preferred cereal crop in temperate regions.
Meat is largely a product of grass crops and grassland with 45% of world meat production coming from ruminant animals grazing grass crops, grassland, or fed cereal grains. The remaining 55%, pork and poultry meat and eggs, is produced from animals eating rations based on cereal grains.
Grasses also include many serious weeds, some of the more serious are similar to the crops they infest making their eradication very difficult. A number of species are declared noxious weeds in this state.
Note: where there is more than 1 bisexual floret or spikelet, all measurements refer to the lowest floret unless otherwise indicated.
| | Key to the family POACEAE | |
| 1 | Mature spikelets falling entire from their pedicels (except for Arundinella and more or less persistent on a flat, indistinctly and tardily disarticulating rachis as in Stenotaphrum), all alike or differing in sex, size, shape, or structure; fertile spikelets usually with 2 florets, the upper bisexual or female, the lower male or sterile (rarely both bisexual as in Isachne spp.); rachilla not produced beyond the upper floret; lower glume occasionally suppressed | 2 |
| 2 | Male and female spikelets in separate inflorescences or in different parts of the same inflorescence and different in appearance; lemmas hyaline or membranous and thinner than the glumes | 3 |
| 3 | Male and female spikelets in different inflorescences on the same plant | Zea |
| 3* | Male and female spikelets separated but in the same inflorescence; female spikelet surrounded by a hardened utricle | Coix |
| 2* | Spikelets all bisexual or with male, sterile and bisexual spikelets mixed in the inflorescence and so arranged that a male or sterile spikelet is near a bisexual spikelet or, if spikelets all unisexual, then the lemma of the fertile floret hardened | 4 |
| 4 | Spikelets usually in pairs or threes with 1 sessile and the other(s) pedicellate, or more rarely both pedicellate with 1 shorter and the other longer pedicellate or rarely the pedicellate spikelet reduced to the pedicel or absent, those of each pair or trio alike in sex or different, falling entire at maturity; glumes often more or less rigid or at least firmer and longer than the lemmas (excluding awns); lemmas membranous or hyaline; in the bisexual or female spikelets the upper lemma often awned with an usually geniculate awn or the awn reduced or absent | 17 |
| 4* | Spikelets solitary, or if in pairs or threes then all virtually similar; glumes usually herbaceous or membranous, more rarely hardened, the lower glume usually smaller than the upper or sometimes completely suppressed; lower lemma (mostly sterile) usually resembling the upper glume in texture and often in size; upper lemma from papery to very tough and rigid, rarely hyaline (Neurachne, Thyridolepis), usually awnless (occasionally mucronate) | 44 |
| 1* | Mature spikelets mostly breaking up above the more or less persistent glumes or, if falling entire, then neither 2-flowered nor with the upper floret bisexual and the lower floret male or sterile; spikelets 1–many-flowered; rachilla often produced beyond uppermost floret | 5 |
| 5 | Shrubs or trees with woody, often tall persistent culms, very rarely perennial herbs; leaf blades flat, many-nerved, often with manifest transverse veins, usually with a petiole-like base and articulated with the sheath | 6 |
| 6 | Rhizomes short, pachymorph ('non-running') forming dense slow-growing clumps | Bambusa |
| 6* | Rhizomes elongate, leptomorph ('running') forming extensive stands | 7 |
| 7 | Internodes more or less cylindrical | Arundinaria |
| 7* | Internodes distinctly grooved | Phyllostachys |
| 5* | Perennial or annual herbs with herbaceous or rarely somewhat woody culms; leaf blades usually sessile and not articulated with the sheaths, very rarely with a petiole-like base | 8 |
| 8 | Spikelets sessile or shortly pedicellate along 1 side of the rachis of digitate, solitary or scattered spikes or spicate racemes | 80 |
| 8* | Spikelets borne in open or contracted spicate panicles, less often in racemes or spikes but then the spikelets on both sides of the axis | 9 |
| 9 | Spikelets with 1 fertile floret, with or without 1 or 2 male or sterile florets below it | 10 |
| 10 | Stamens 3, 4 or 2; palea 2-nerved (except nerveless and without keels in Nassella); glumes (or at least the upper glume) well developed or occasionally minute | 88 |
| 10* | Stamens usually 6; palea 3–9-nerved; glumes very small and hyaline or reduced to an obscure rim at the apex of the pedicel or suppressed; aquatic grasses | 11 |
| 11 | Glumes small and hyaline; florets not compressed or keeled; palea 5-nerved, the lemma 7-nerved, both thinly membranous; coarse tufted perennials in or on the margins of moderately fast-flowing rivers | Potamophila |
| 11* | Glumes reduced to a hyaline rim; florets strongly compressed; palea 2- or 3-nerved, the lemma 5-nerved; annual or slender rhizomatous perennials | 12 |
| 12 | Sterile lemmas absent, both lemma and palea 1-keeled and ciliate on the keels, the palea 3-nerved, the lemma 5-nerved; slender rhizomatous perennials | Leersia |
| 12* | Two sterile lemmas present below the fertile lemma, keeled, the palea 2-nerved, the lemma 5-nerved; slender to robust, erect annual (in N.S.W.) | Oryza |
| 9* | Spikelets usually with 2 or more fertile florets, or if with 1 fertile floret then with sterile florets above it | 13 |
| 13 | Lemmas or rachilla joints bearing long silky hairs that envelope the lemma (at least in fertile florets); lemmas awnless or with a straight awn from the tip, often thin; tall grasses with large plume-like panicles | 14 |
| 14 | Leaves very long and crowded at the base of the culms; spikelets unisexual or bisexual; lemma of female spikelets covered with long hairs | Cortaderia |
| 14* | Leaves distributed along the culms; tall stout 'reeds'; spikelets bisexual | 15 |
| 15 | Lemmas hairy; rachilla joints naked | Arundo |
| 15* | Lemma naked; rachilla joints hairy | Phragmites |
| 13* | Lemmas and rachilla joints either glabrous or hairy, if hairy the hairs either not enveloping the lemma or, if so, the lemma bearing a geniculate awn; low to moderately tall grasses | 16 |
| 16 | Glumes from 60% as long to longer than the lowest floret, sometimes as long as the spikelet and enclosing the florets; lemma awned from the back or from the sinus of a 2-lobed tip with a geniculate or straight awn or mucro (but the awn, when present, terminal and straight in Eriachne), or awnless; leaves never rigid and pungent-pointed | 115 |
| 16* | Glumes usually shorter than the lowest floret and with the upper florets distinctly exserted, rarely longer and then usually with firm dull margins like the lemmas or with the lemmas cleft into 9 lobes or awns or the leaves rigid and pungent pointed; lemmas awnless or with a straight or curved awn from the entire or 2-fid apex, or several-awned or -lobed; leaves rigid and pungent-pointed or not | 132 |
| 17 | Internodes of the raceme axis and also the pedicels stout, more or less thickened upwards, 3-angled or rounded, often more or less hollowed out on one side | 18 |
| 18 | Lower glume fringed on the keels with stiff scabrid, antrorsely-curved spines; raceme solitary, terminal, 1-sided; the sessile spikelets overlapping, accompanied by a pedicel that may or may not bear a rudimentary spikelet | Eremochloa |
| 18* | Lower glume not fringed with stiff spines; raceme various | 20 |
| 20 | Internodes and pedicels fused to form roughly semi-cylindric internodes | 21 |
| 21 | Spikelets of each pair more or less similar | Hemarthria |
| 21* | Pedicellate spikelet of each pair male or sterile | Rottboellia |
| 19* | Internodes and pedicels not fused together | 22 |
| 22 | Racemes paired or digitate [rarely solitary]; lower glume of sessile spikelet more or less winged on the keels, the upper not awned; pedicels inflated | Ischaemum |
| 22* | Racemes solitary; lower glume of sessile spikelet not winged, the upper awnless or awned; pedicels not inflated | 23 |
| 23 | Lower glume of sessile spikelet fringed with stiff hairs and apex elongated into two (sometimes partly fused) awn-like teeth or lobes as long as the body of the glume; upper glume awnless | Elyonurus |
| 23* | Lower glume of sessile spikelet not fringed with stiff hairs and 2-toothed without an awn-like process; upper glume awned | Sehima |
| 17* | Internodes of the raceme axis and pedicels slender, cylindrical or flattened; lower floret of sessile spikelet sterile | 24 |
| 24 | Spikelets of each pair alike in sex and shape | 25 |
| 25 | Spikelets all pedicellate, 1 of each pair shortly, the other longer pedicellate | 26 |
| 26 | Spikelets awnless; panicles spicate, dense, whitish; culms from a long, creeping rhizome; blades narrow at the base | Imperata |
| 26* | Spikelets awned; inflorescence of few–many racemes 10–25 cm long, much exceeding the primary axis; robust, caespitose perennial with linear leaves | Miscanthus |
| 25* | One spikelet of each pair sessile, the other pedicellate; spikelets awned | 27 |
| 27 | Culms more than 1.5 m high when mature, with many-noded culms more than 2 cm diam.; leaves usually more than 5 cm wide; inflorescence large, paniculate, white; fertile lemma with a straight, short, terminal awn | Saccharum |
| 27* | Culms less than 1.5 m high, culms with few nodes and less than 1 cm diam.; leaves less than 2 cm wide | 28 |
| 28 | Spikelets unawned though the apex of the lower glume of sessile spikelet with two (sometimes partly fused) awn-like teeth longer than the body of the glume | Elyonurus |
| 28* | Spikelets awned; apex of lower glume without awn-like teeth | 29 |
| 29 | Caespitose perennial with narrow-linear leaves; racemes digitate or subdigitate, silky-villous with yellowish hairs | Eulalia |
| 29* | Slender decumbent annual with lanceolate leaf blades; racemes 3–6, somewhat distant on a short axis, not manifestly villous | Microstegium |
| 24* | Pairs (or threes) of spikelets dissimilar in sex and more or less in shape (or if those of some pairs of a raceme are alike then both male or sterile); fertile spikelets usually awned | 30 |
| 30 | Upper lemma of fertile spikelets awned from low down on the back; pedicellate spikelets reduced to their pedicels or these also absent and the sessile spikelets solitary; slender decumbent grass, rooting at the nodes, with lanceolate, cordate leaf blades | Arthraxon |
| 30* | Upper lemma of the sessile spikelet awned from the tip or 2-toothed or 2-lobed and awned from the sinus, rarely awnless; caespitose grasses | 31 |
| 31 | Racemes in more or less compound espatheate panicles with the more or less elongated branches usually opposite or whorled on a more or less elongated axis | 32 |
| 32 | Joints and pedicels without a longitudinal depression, usually circular or elliptic in cross section | 33 |
| 33 | Sessile spikelets and grain more or less dorsally compressed at least when in flower, the lower glume never scabrous on the keels | Sorghum |
| 33* | Sessile spikelets and grain more or less laterally compressed, the lower glume more or less scabrous on the keels | 34 |
| 34 | Racemes with 1 or 2 (rarely 3) joints (nodes), if regularly more than 1-jointed then the awn geniculate and twisted with a prominent column; leaf blades involute or convolute | Chrysopogon |
| 34* | Racemes with 3–several joints (nodes) rarely less in the same panicle; awn bristle-like without a distinctly differentiated column, or absent; leaf blades flat or folded, the sheaths keeled | Chrysopogon |
| 32* | Joints and pedicels with a longitudinal depression, dumbbell-shaped in cross section | 35 |
| 35 | Racemes with 1–8 joints (nodes); panicle open with capillary branches | Capillipedium |
| 35* | Racemes with more than 8 joints; inflorescence of racemes on an elongated axis | Bothriochloa |
| 31* | Racemes either espatheate and solitary, digitate or subdigitate, or in spatheate panicles | 36 |
| 36 | Racemes espatheate, digitate or subdigitate, rarely solitary; fertile spikelets dorsally compressed and the lower glume more or less 2-keeled, the callus short and obtuse; awn glabrous; culms simple or branching from the lower nodes | 37 |
| 37 | Joints and pedicels with a longitudinal depression, dumbbell-shaped in cross section; racemes without spikelets at the base, the lower sessile spikelets all fertile and awned | Bothriochloa |
| 37* | Joints and pedicels without a longitudinal depression, circular or elliptic in cross section; racemes sessile with the sessile spikelets of the lower 1–3 pairs sterile and awnless | Dichanthium |
| 36* | Racemes spatheate or gathered into spatheate panicles | 38 |
| 38 | Racemes falling entire at maturity either separately or together with their spathes, consisting of only 1 fertile spikelet subtended by a false involucre of sterile spikelets | Iseilema |
| 38* | Racemes breaking up at maturity, the spathe and sometimes the lower (and then sterile) part of the raceme persistent | 39 |
| 39 | Fertile spikelet more or less terete (slightly flattened dorsally in Hyparrhenia), usually with a more or less pungent callus; awn, or at least its column, hairy; lower 1–few pairs of spikelets usually sterile | 40 |
| 40 | Basal sterile spikelets forming a false involucre around the fertile spikelet on the 1-jointed (noded) racemes solitary in the ultimate spathes | Themeda |
| 40* | Basal sterile spikelets not forming an involucre around the fertile spikelet; culms much branched from the upper nodes | 41 |
| 41 | Racemes paired on very slender peduncles in the ultimate spathes; callus subacute or acuminate | Hyparrhenia |
| 41* | Racemes solitary on the ends of the culm branches, secund, the bases of the sterile spikelets subimbricate on the back of the raceme; callus very pungent | Heteropogon |
| 39* | Fertile spikelet either dorsally or laterally compressed, the lower glume more or less 2-keeled; callus short and obtuse; fertile lemma 2-fid and awned from the sinus, the awn usually glabrous | 42 |
| 42 | Racemes solitary on each peduncle, the rachis very slender and fragile | Schizachyrium |
| 42* | Racemes in pairs or more or less digitate on each peduncle, the rachis not as slender or fragile | 43 |
| 43 | Racemes 2–4 on each peduncle, approximate or at length somewhat diverging, the rachis slender and fragile; pedicellate spikelet reduced to its pedicel | Andropogon |
| 43* | Racemes 2, at first approximate but soon sharply deflexed, the rachis less markedly slender and fragile; pedicellate spikelets developed | Cymbopogon |
| 44 | Spikelets disarticulating above the glumes | Arundinella |
| 44* | Spikelets disarticulating below the glumes | 45 |
| 45 | Spikelets virtually all bisexual | 46 |
| 46 | Spikelets dimorphic, some chasmogamous on simple, spicate, terminal racemes, others cleistogamous, compressed; rigid, branching perennials | Cleistochloa |
| 46* | Spikelets virtually all alike | 47 |
| 47 | Fertile lemma densely hairy with fine, white, more or less appressed hairs | Entolasia |
| 47* | Fertile lemma glabrous on the back | 48 |
| 48 | Main axis of the panicle or racemes not disarticulating and the racemes persistent on the main axis, the spikelets not falling attached to the segments or, if so, then the spikelets or groups of spikelets variously subtended by bristles or by a spiny or bristly involucre | 49 |
| 49 | Spikelets not subtended by bristles or an involucre (rarely subtended by a corona of very short, fine hairs) | 50 |
| 50 | Fertile lemma and palea not much harder than, or softer than the glumes | 51 |
| 51 | Low spreading stoloniferous perennial in saltmarsh with leaf blades less than 2 mm wide | Alexfloydia |
| 51* | Ceaspitose or stoloniferous perennials; if stoloniferous then leaves more than 3mm wide and not growing in saltmarshes | 52 |
| 52 | Spikelets less than 3 mm long, lower lemma shortly awned between 2 lobes; leaves sticky | Melinis |
| 52* | Spikelets more than 3 mm long, lemmas awnless; leaves not sticky | 53 |
| 53 | Lower glume with a depressed vertical window surmounted by a thick transverse ridge bearing bristles | Thyridolepis |
| 53* | Lower glume without a 'window' or ridge with bristles | Neurachne |
| 50* | Upper lemma more or less thickened or indurate, or if subhyaline then the upper glume and sterile lemma acuminate or tapering into long points and the panicle branches produced beyond the uppermost spikelet, or else the spikelets concealed amongst silky hairs | 54 |
| 54 | Glumes and sterile lemma with spreading, hooked or curved, tubercle-based hairs; fertile lemma thinly cartilaginous with flat hyaline margins; rigid, branching perennials almost shrubby or scrambling | Ancistrachne |
| 54* | Glumes and lemma without spreading hooked or curved hairs | 55 |
| 55 | Both florets fertile, or if the lower floret male then its lemma very similar to the upper and hardened; glumes more or less equal and similar; spikelets globose, small, awnless | Isachne |
| 55* | Lower floret male or sterile, its lemma usually differing in texture or size from the lemma of the upper floret; glumes usually unequal or dissimilar (rarely subequal and similar as in Ottochloa and then the spikelets not distinctly globose), the lower (very rarely both) suppressed | 56 |
| 56 | Lower glume rudimentary and forming, with the base of the rachilla, a swollen annular callus subtending the lower glume; fertile floret hardened, usually with a small apical mucro | Eriochloa |
| 56* | Spikelet not subtended by a swollen annular callus | 57 |
| 57 | Fertile lemma thinly cartilaginous to indurate with more or less flat, thin or hyaline margins enveloping the margins of the palea; spikelets borne on (1-or) few–many-flowered spicate racemes that are digitately, subdigitately or racemosely arranged on a common axis, or rarely solitary | 58 |
| 58 | Lower glume subequal to the spikelet; sterile lemma with a subequal palea | Homopholis |
| 58* | Lower glume less than 60% the length of the spikelet; sterile lemma with a minute scale-like palea that often remains attached to the base of the fertile floret | 59 |
| 59 | Fertile lemma shortly awned, the margins firm but thinner than the back; sterile lemma thinly cartilaginous like the fertile; upper glume densely ciliate along the outer nerves, the rigid cilia at first appressed then later spreading | Alloteropsis |
| 59* | Spikelets unawned, occasionally the fertile lemma terminating in a very minute inconspicuous mucro; fertile lemma with thin, flat, hyaline margins; indumentum various but the upper glume not, and the sterile lemma very rarely, ciliate | Digitaria |
| 57* | Either the fertile lemma with more or less inrolled thickened margins or the spikelets not borne on slender racemes on a common axis, or both | 60 |
| 60 | Spikelets awnless; fertile lemma rugulose or smooth | 61 |
| 61 | Inflorescence of variously arranged (rarely solitary), simple or compound, usually more or less secund, often spicate, dense or loose racemes, not an open, or contracted and cylindrical, panicle; spikelets often in pedicellate pairs or threes or solitary, alternately to the left and right of the median line of a usually triquetrous or compressed, dorsiventral rachis | 62 |
| 62 | Back of the fertile lemma abaxial, the lower glume (if present) adaxial | 63 |
| 63 | Lower glume absent; racemes digitate or subdigitate | Axonopus |
| 63* | Lower glume present and well developed; racemes arranged racemosely along the main axis | 64 |
| 64 | Upper lemma smooth and shiny, neither awned nor apiculate | Brachiaria |
| 64* | Upper lemma coarsely or finely rugose or rugulose, usually awned or apiculate | Urochloa |
| 62* | Back of the fertile lemma adaxial, the lower glume (if present) abaxial | 65 |
| 65 | Rachis of the racemes produced into a distinct short bristle beyond the uppermost spikelet; spikelets often very convex on the back and more or less depressed on the face, secund on the short, slender, sessile, spicate racemes | Paspalidium |
| 65* | Rachis of the racemes not produced into a bristle beyond the uppermost spikelet | 66 |
| 66 | Lower glume little shorter than the upper and similar in appearance, both glumes shorter than and exposing the fertile lemma; margins of the fertile lemma very narrowly hyaline and minutely ciliolate upwards, entirely covering the tip of the palea; delicate decumbent or scrambling perennials | Ottochloa |
| 66* | Lower glume very much shorter than the upper or absent; spikelets shortly to very shortly pedicellate and usually more or less crowded or secund, spicate racemes | 67 |
| 67 | Lower glume generally absent | Paspalum |
| 67* | Lower glume present | 68 |
| 68 | Fertile lemma rugose, very obtuse with an abrupt, usually scabrous or barbellate mucro; spikelets more or less flattened, glabrous or softly hairy | Urochloa |
| 68* | Fertile lemma smooth and shining, acute or acuminately pointed, the margins inrolled below but more or less flat above and not enclosing the tip of the palea; spikelets turgid, often stiffly hispid | Echinochloa |
| 61* | Inflorescence either an open panicle or else contracted, cylindrical and spicate | 69 |
| 69 | Inflorescence a large or small, more or less open panicle; spikelets not gibbous | 70 |
| 70 | Low spreading stoloniferous perennials in saltmarsh with leaf blades less than 2 mm wide; spikelets often appearing laterally flattened; inflorescences 3–6-flowered, the spikelets 3–4 mm long | Alexfloydia |
| 70* | Caespitose or stoloniferous annuals or perennials; if stoloniferous perennials then leaf blades more than 2 mm wide, the spikelets usually appearing dorsiventrally flattened and more than 6 per inflorescence, and less than 3 or more than 4 mm long | Panicum |
| 69* | Inflorescence a contracted, cylindrical, spicate panicle; spikelets gibbous | Sacciolepis |
| 60* | Either the glume(s) and/or the sterile lemma awned or mucronate, or the partial rachis produced into a long, awn-like point beyond the uppermost spikelet and then the upper glume and fertile lemma long acuminate; fertile lemma smooth | 71 |
| 71 | Upper glume and sterile lemma concealed by copious, long, silky hairs and somewhat gibbous about the middle, awned from the slightly notched tip, laterally compressed; panicles spreading | Melinis |
| 71* | Upper glume and sterile lemma glabrous or pubescent but not concealed by long silky hairs | 72 |
| 72 | Glumes subequal, herbaceous, the lower awned from the back of an entire apex; spikelets in small clusters or 1- or 2-nate, secund on more or less short, spicate racemes that are racemosely arranged on a common axis; weak ascending grasses with slender, several-noded culms and lanceolate leaves | Oplismenus |
| 72* | Glumes very unequal, the lower not or scarcely awned; awns terminal (if present) on the upper glume and/or sterile lemma | 73 |
| 73 | Rachis not conspicuously produced beyond the uppermost spikelet; upper glumes and sterile lemma both usually hispid with more or less stiff or bristly hairs; upper floret bisexual; spikelets crowded in rows or irregularly along mostly simple, 1-sided, spicate branches of a panicle | Echinochloa |
| 73* | Rachis conspicuously produced into a long awn-like point beyond the uppermost spikelet; upper floret usually female, much shorter than the lower male floret; panicles either loosely spicate or spreading | Pseudoraphis |
| 49* | Spikelets (or some of them) or groups of spikelets subtended by 1 to several bristles that may be simple or fused into an involucre, or by branches bearing groups of bristles | 74 |
| 74 | Spikelets solitary or several together in racemes distant along the axis and the racemes (or solitary spikelets) disarticulating as a whole from the main axis | 75 |
| 75 | Spikelets several together on the racemes, the lowest or lower subtended by a bristle (the prolongation of the rachis of a reduced lateral branch) and the rachis prolonged as a bristle beyond the uppermost spikelet | Paractaenum |
| 75* | Spikelets solitary on the branches and subtended by 3 or 4 sterile branches that terminate in bristle-like branches, very rarely bearing a second spikelet | Plagiosetum |
| 74* | Spikelets solitary or in clusters on the branches of more or less contracted, spicate (rarely open) panicles, the spikelets or clusters falling from the (common) pedicels | 76 |
| 76 | Bristles (rarely 1–few) persistent on the pedicels, the spikelets deciduous | Setaria |
| 76* | Bristles or involucre falling with the spikelets at maturity | 77 |
| 77 | Bristles not united at the base, slender, smooth, antrorsely scabrous, ciliate or plumose, the spikelets solitary or in groups of 2–5 | Pennisetum |
| 77* | Bristles united into a burr-like involucre (more rarely only slightly united at the base) around a solitary spikelet or group of 2–7 spikelets | Cenchrus |
| 48* | Main axis of the more or less spicate panicle readily or tardily or partially disarticulating into segments, the spikelets not subtended by bristles or an involucre | 78 |
| 78 | Spikelets falling entire (sometimes tardily) from the rudimentary pedicels, solitary or 2–5 (rarely more) on short spicate racemes that are more or less sunk in hollows (or at least closely appressed) on 1 side of a flattened, or spongy continuous or jointed common axis; stoloniferous perennials with rather broad, obtuse blades and short flowering culms; spikelets rarely maturing seed | Stenotaphrum |
| 78* | Spikelets sessile, few together (usually 2–4) on short spikes on a readily disarticulating, flattened common axis, the spikes falling entire with a segment of the axis; annual | Uranthoecium |
| 45* | Spikelets unisexual and the plants dioecious, the spikelets in more or less dense heads subtended by bracts, the female heads globose or hemispherical | 79 |
| 79 | Female heads about 2.5–3.5 cm diam., slightly bristly with the curved points of the bracteoles; male heads globose or hemispherical, 1–2 cm diam., the lowermost bract usually exceeding the head; rigid, branched bushy hummock-forming grass to 1.5 m high with stout creeping rhizomes; lunettes of inland lakes and inland sand dunes | Zygochloa |
| 79* | Female heads large, about 20–30 cm diam., each spikelet solitary at the base of a long, spicate rachis; male spikelets few–many in sessile or pedunculate spikes clustered in a terminal head and often with other heads lower down on the stem, each spike about 2–4 cm long; plants forming tufts with long, trailing stolons on coastal sand dunes | Spinifex |
| 80 | Spikelets with 1 fertile floret, with or without 1 or more imperfect florets above it | 81 |
| 81 | Fertile floret with 1 or more imperfect floret(s) above it; lemmas usually awned or mucronate | 81 |
| 82 | Glumes subequal, the upper mucronate; lemmas awnless or mucronate | Eustachys |
| 82* | Glumes unequal, acute, acuminate or aristulate; lemmas awned | 83 |
| 83 | Lemmas laterally compressed | Chloris |
| 83* | Lemmas dorsally compressed | Enteropogon |
| 81* | Fertile floret without an imperfect floret above it though often the rachilla produced and rarely bearing a minute abortive floret; lemmas usually not awned | 84 |
| 84 | Glumes longer than the floret | Brachyachne |
| 84* | Glumes shorter than the floret | Cynodon |
| 80* | Spikelets with 2 or more fertile florets | 85 |
| 85 | Axes of the spikes producing a bristle or acute point | Dactyloctenium |
| 85* | Axes of the spikes ending in perfect or aborted spikelets, not projecting as a sterile bristle | 86 |
| 86 | Lemmas prominently lobed with the central segment tapering into a short, stiff, straight or terminally hooked awn | Astrebla |
| 86* | Lemmas truncate, entire, erose or mucronate but not prominently lobed | 87 |
| 87 | Lemmas entire, acute | Eleusine |
| 87* | Lemmas truncate or erose or minutely notched, rarely mucronate | Leptochloa |
| 88 | Spikelets with 1 or 2 florets; glumes (or at least the upper) well-developed | 89 |
| 89 | Spikelets falling entire at maturity, either singly or in clusters, from the axis of slender, spicate panicles or racemes; lemmas delicate, 1–3-nerved | 90 |
| 90 | Spikelets in deciduous, burr-like clusters of 2 (in the N.S.W. species) to 6; lower glume minute or suppressed; upper glume 5-nerved and hispid or spinous with hooked spines on the nerves | Tragus |
| 90* | Spikelets borne singly or very shortly pedicellate on the continuous axis of a solitary, terminal spike or spicate raceme | 91 |
| 91 | Lower glume absent; upper glume awnless or mucronate or with a very slender awn to 3 mm long; low, rhizomatous or stoloniferous perennials | Zoysia |
| 91* | Glumes more or less equal and similar, tapering into long capillary awns; annual (in the N.S.W. species) | Perotis |
| 89* | Spikelets usually breaking up at maturity, the rachilla disarticualting above the more or less persistent glumes, or if falling entire then with firmly membranous awned or 5-nerved lemmas | 92 |
| 92 | Lemmas more or less hardened and rigid at maturity, more or less terete or slightly dorsally compressed, with convolute or involute margins tightly enveloping the grain, with a terminal awn or awns or cleft into usually awned segments, rarely awnless | 93 |
| 93 | Lemma terminating in a single undivided awn | 94 |
| 94 | Lemma usually several times longer than broad, narrow, cylindrical, sometimes slightly gibbous, tapering at the tip or sometimes slightly 2-lobed, convolute and totally enclosing the palea; awned from the apex of the lemma or from between its lobes, more or less persistent or tardily deciduous, twisted in the lower part, usually once or twice geniculate; callus longer than the breadth of the lemma, very oblique, sharp-pointed and bearded | Stipa |
| 94* | Lemma short and broad; awn slender, deciduous; callus shorter than the breadth of the lemma | 95 |
| 95 | Lemma elliptic-oblong, not gibbous at the top; awn terminal and central from the minutely-lobed apex, straight, deciduous; palea 2-nerved, shorter than or subequal to the lemma | Piptatherum |
| 95* | Lemma asymmetric, gibbous at the summit; awn eccentrically attached, deciduous; palea short, hyaline, without nerves or keels | Nassella |
| 93* | Lemma 3–5-cleft or 3–5-awned, or terminating in a single awn that branches above into 3 awns | 96 |
| 96 | Lemma 5-awned, the central awn stronger than the laterals, geniculate and twisted below the bend, the 4 lateral awns slender, straight or curved but not twisted | Pentapogon |
| 96* | Lemma 3-cleft or 3-awned or the single awn 3-branched | 97 |
| 97 | Lemma deeply 3-cleft with each segment usually awned; body of the lemma shortly oblong or ovate, with a short, obtuse or scarcely pointed callus (in the N.S.W. species); palea deeply 2-cleft with each segment usually awned similarly to the lemma | Amphipogon |
| 97* | Lemma 3-awned or the single awn 3-branched, cylindric or linear oblong with a pointed callus; palea not deeply cleft | 98 |
| 98 | Awns (or branches) more or less similar (at least in the N.S.W. species), straight or somewhat curved; lemma tightly convolute or pseudo-involute, concealing the palea; rachilla not produced above the fertile floret; glumes 1-nerved (rarely to 5-nerved) | Aristida |
| 98* | Awns very unequal, the central much longer, very robust and geniculate and twisted below the bend, the laterals slender, straight or curved and not or scarcely twisted; lemma convolute, at the apex not concealing the palea which extends beyond the point of insertion of the awns; spikelets very large, the glumes 3–5.5 cm long and more than 5-nerved; rachilla produced beyond the fertile floret, sometimes bearing an aborted floret | Anisopogon |
| 92* | Lemmas hyaline or membranous at maturity and awnless or dorsally (sometimes only slightly so, almost subterminally) awned, or more rarely terminally awned from the entire and obtuse or minutely toothed apex, or if the lemma hardened then the awn clearly dorsal or the glumes ciliate on the keels or the spikelets and lemmas more or less laterally compressed | 99 |
| 99 | Lemmas 1–3-nerved, awnless; glumes and lemma very similar in texture, thinly to very firmly membranous or hyaline, often somewhat shining; grain free (at maturity) in a delicate pericarp, falling free from the lemma and palea | Sporobolus |
| 99* | Lemma usually 3–5-nerved, frequently awned; glumes differing in texture from the lemma, usually longer and firmer than the hyaline lemma, but if shorter than the lemma or if the lemma is hardened then the glumes membranous and dull; grain usually with an adhering pericarp | 100 |
| 100 | Rachilla disarticulating below the glumes, the spikelet falling entire at maturity; panicles dense and spicate | 101 |
| 101 | Glumes both awned from the entire apex or from the sinus between the 2 obtuse, short lobes of the apex, the awns very delicate, 4–7 mm long; lemma very thin, with a broad, blunt, minutely toothed tip, awnless or with an awn to 2 mm long from the tip | Polypogon |
| 101* | Glumes awnless, lemma membranous with a slender dorsal awn | 102 |
| 102 | Glumes more or less ciliate on the keel; inflorescence dense and spicate | Alopecurus |
| 102* | Glumes not ciliate on the keels; panicle open or dense and contracted but not spicate | Agrostis |
| 100* | Rachilla disarticulating above the glumes | 103 |
| 103 | Glumes either feathery-hairy, or glabrous, swollen, hardened and shining at the base | 104 |
| 104 | Glumes feathery-hairy, each tapering into a fine bristle; panicle dense, spicate, globose to ovoid or oblong-cylindrical; lemma narrowed into 2 teeth and bearing a dorsal geniculate awn | Lagurus |
| 104* | Glumes glabrous, acuminate, at the base swollen, hardened and shining; lemma very blunt, minutely toothed, awnless or with a slender, dorsal, geniculate awn; panicles narrow-lanceolate, oblong or cylindrical, dense and spicate | Gastridium |
| 103* | Glumes neither feathery-hairy nor swollen at the base | 105 |
| 105 | Glumes abruptly truncate with a short, rigid awn 1–2 mm long produced at the tip above the keel (in the species in N.S.W.), the keels fringed with cilia; spikelets oblong, very flattened, tightly packed in a dense, spicate, cylindrical panicle; lemma membranous, very blunt, awnless | Phleum |
| 105* | Glumes obtuse, acute or acuminate but not abruptly truncate, and not or scarcely awned | 106 |
| 106 | Lemmas membranous or at least very thin, obtuse or truncate, smooth or softly hairy; panicles spreading or contracted but not or scarcely spicate; spikelets (at least in the N.S.W. species) less than 8 mm long; palea as long as to much shorter than the lemma or absent | Agrostis |
| 106* | Lemmas thinly papery to hardened, more or less scaberulous or scabrous at least upwards, never completely smooth and shining; palea usually well developed | 107 |
| 107 | Spikelets 9–16 mm long; lemma lanceolate to narrow-lanceolate to oblong, obtuse, very compressed and keeled, awnless or with a minute dorsal awn behind the tip; panicles spicate, narrow-oblong to cylindrical, tapering upwards, dense, pale; coarse perennial on coastal sand dunes forming dense tussocks with stout rhizomes and long leaves | Ammophila |
| 107* | Spikelets less than 9 mm long, or if longer then the lemma either 2-cleft and awned or mucronate from the sinus or entire and awned from near the apex with an awn twice or more the length of the lemma and the lemma linear | 108 |
| 108 | Glumes rigidly ciliate on the keel; lemma entire or 2-cleft with the lobes sometimes aristate, and awned or mucronate from the sinus, 5–11-nerved; panicle spicate, sometimes dense | Echinopogon |
| 108* | Glumes smooth or scabrous on the keel but not ciliate; lemma entire or minutely (often 4-) toothed | 109 |
| 109 | Lemma lanceolate, or broad-oblong (and then very small), usually more or less hardened at maturity and usually minutely (often 4-) toothed at the apex, minutely or shortly awned or rarely awnless, the awn not twice as long as the lemma | Deyeuxia |
| 109* | Lemma linear or very narrowly linear-lanceolate, entire or minutely notched with a slender dorsal awn twice to several times as long as the lemma | Dichelachne |
| 88* | Spikelets with 3 florets, the terminal floret bisexual, the lower 2 florets male or sterile and sometimes reduced to small or minute scales, articulate above the glumes, the florets falling together; glumes well developed or minute | 110 |
| 110 | Lower florets male and with 2-nerved paleas; glumes well developed, half as long to as long as the lemma; panicle loose or loosely contracted; spikelets often brown and/or shining; plants often fragrant; lodicules present | Hierochloe |
| 110* | Lower florets sterile and without paleas; plants fragrant or not fragrant | 111 |
| 111 | Upper or both glumes as longer or longer than the florets | 112 |
| 112 | Upper glume as long or longer than the florets, the lower about half as long, both thinly membranous; lower sterile lemma awned from high up on the back, the upper lemma with a stouter geniculate awn near the base; panicle spicate, 1–4 cm long; plants fragrant; lodicules absent | Anthoxanthum |
| 112* | Both glumes longer than and concealing the florets; sterile lemmas reduced to small scales adhering closely to the base of the fertile lemma; fertile florets papery and tough, smooth and more or less shining though often thinly hairy; spikelets strongly laterally compressed, the glumes strongly keeled and often winged on the keels; panicle usually spicate, sometimes somewhat interrupted and branching; plants not fragrant | Phalaris |
| 111* | Both glumes distinctly shorter than the florets, sometimes minute | 113 |
| 113 | Caryopsis elliptic in outline, strongly laterally compressed; stamens 6 or 3, rarely 1; sterile florets smooth, hairy, or transversely wrinkled, sometimes with appendages at the base; spikelets in contracted or open panicles or racemes | Ehrharta |
| 113* | Caryopsis linear or oblong in outline, very turgid at maturity; stamens 2–6 but usually 4; sterile florets smooth or scabrous but neither hairy (except sometimes with small tufts of hair at the base) nor wrinkled; spikelets in narrow panicles or racemes | 114 |
| 114 | Caryopsis linear; stamens 2–6 but usually 4; sterile florets terminating in distinct, often long, awns, elongate, slender, scabrous, either with the callus very hairy or the lemmas with small tufts of hairs at the base, arranged in narrow, sometimes drooping panicles or racemes with capillary branches and pedicels; glumes small, sometimes minute | Microlaena |
| 114* | Caryopsis oblong; stamens 4; sterile florets very obtuse or truncate to acuminate or mucronate but not awned, without tufts of hair at the base and the callus glabrous, arranged alternately on spicate erect racemes (in N.S.W. species) and with short stiff pedicels | Tetrarrhena |
| 115 | Lemma awned from the back, or awnless (and then usually annuals), the apex entire or notched; ligule membranous | 116 |
| 116 | Spikelets mostly 4–10-flowered; panicles loose or loosely contracted; spikelets about 1 cm or more long, scarcely compressed; lemma with a rather long geniculate awn from the back; aquatic or semi-aquatic grasses | Amphibromus |
| 116* | Spikelets 2- or 3-flowered, or if up to 6-flowered then the awn short and straight; non-aquatic species | 117 |
| 117 | Florets 2 (or 3), 1 bisexual, the other male | 118 |
| 118 | Lowest floret usually male and bearing a geniculate awn, the second bisexual and awnless, falling together at maturity | Arrhenatherum |
| 118* | Lowest floret bisexual and awnless, the upper male with a short awn near the tip, the spikelets falling entire at maturity, compressed | Holcus |
| 117* | Florets (or at least the lower pair) alike and bisexual | 119 |
| 119 | Spikelets 1 cm or more in length, nodding; florets 2 or 3, the lower 1 or 2 usually awned from the back with a long geniculate awn; glumes closely 7–11-nerved; annuals | Avena |
| 119* | Spikelets less than 1 cm long, erect | 120 |
| 120 | Spikelets strictly 2-flowered, with the florets subequal, very small | 121 |
| 121 | Glumes longer than the usually awned florets | Aira |
| 121* | Glumes shorter than the awnless florets | Periballia |
| 120* | Spikelets 3–6-flowered or rarely with the third floret reduced and rudimentary | 122 |
| 122 | Annuals with terminal or subterminal awns | Rostraria |
| 122* | Perennials with dorsal awns or awnless | 123 |
| 123 | Panicles spreading; awns straight, from near the base of the lemma, mostly included within the glumes | Deschampsia |
| 123* | Panicles dense and spicate; awns dorsal or awnless | 124 |
| 124 | Lemmas with a dorsal geniculate awn shortly exserted from the glumes | Trisetum |
| 124* | Lemmas awnless or shortly mucronate | Koeleria |
| 115* | Lemma awned or with a mucro from the sinus of a 2-lobed tip, or awnless (and then usually perennials), or rarely the awn terminal (in Eriachne); ligule reduced to a row of hairs, or if membranous then erosely ciliate on the margins | 125 |
| 125 | Low tufted annuals with more or less thin soft leaves | 126 |
| 126 | Spikelets 2-flowered with the rachilla shortly produced; lemma thin, narrowed upwards into short, delicate lateral awns and with a longer, fine, geniculate central awn slightly twisted; leaf blades flat | Pentaschistis |
| 126* | Spikelets about 5-flowered; lemma broad, rounded on the back, distinctly 5–9-nerved, with hyaline margins upwards, shortly 2-lobed with a mucro on the lowest lemma and a minute mucro on the upper lemmas between the lobes; leaf blades flat or rolled | Schismus |
| 125* | Perennials (sometimes annuals) with more or less firm, wiry or hard leaves | 127 |
| 127 | Spikelets 2-flowered (rarely 1-flowered); lemma not lobed at the apex, awnless or tapering into a mucro or straight or curved (not twisted) awn | Eriachne |
| 127* | Spikelets 2–several-flowered; lemma more or less 3-lobed, or 2-lobed or 2-cleft and with a mucro or awn from the sinus | 128 |
| 128 | Lower leaf sheaths woolly and swollen; drier areas of the State | Monachather |
| 128* | Lower leaf sheaths not woolly and swollen | 129 |
| 129 | Awns less than 4 mm long, often reduced to a mucro or lemmas awnless and 3-lobed | 130 |
| 130 | Awn less than 4 mm long, often reduced to a mucro | Plinthanthesis |
| 130* | Lemmas 3-lobed, awnless; low-growing alpine grasses | Rytidosperma |
| 129* | Lemma deeply to shortly cleft, the lateral segments often tapering into short awns or points, the central awn more than 4 mm long, geniculate and more or less strongly twisted below the bend | 131 |
| 131 | Hilum more or less 30% as long as the grain, situated in a longitudinal groove; hairs of even length scattered over the back of the lemma | Chionochloa |
| 131* | Hilum less than 30% as long as the grain, grain concave; hairs of the lemma arranged variously but usually of different lengths | Danthonia |
| 132 | Lemmas cleft into 9 (in Australian species) subulate or lanceolate or awned lobes | Enneapogon |
| 132* | Lemmas entire or up to 5-lobed or 5-awned | 133 |
| 133 | Inflorescence spicate with spikelets on opposite sides of the rachis of solitary spikes or spicate racemes; lemmas awnless or with a terminal awn | 134 |
| 134 | Lemmas usually 1–3-nerved; spikelets 1- or 2-flowered, more or less sunken in hollows or depressions in the articulate rachis, more or less enclosed by the glumes | 135 |
| 135 | Glume 1, thin, very much shorter than the floret; lemma thinly hardened, shortly awned, 3-nerved; spikelets distant on the very slender rachis | Psilurus |
| 135* | Glumes 1 or 2, leathery, longer than the floret; lemma awnless; spikelets rather closely spaced on the rachis | 136 |
| 136 | Lower glume very small or suppressed in the lateral spikelets, the upper glume broad and facing the rachis; lemmas of the first (and often only) floret with its back adjacent to the rachis of the spike | Hainardia |
| 136* | Both glumes well developed in the lateral spikelets, placed side by side in front of the cavity in the rachis; lemma with 1 side adjacent to the rachis of the spike | Parapholis |
| 134* | Lemmas 5–9-nerved; spikelets 1–many-flowered, sometimes more or less sunken in depressions in the rachis but then 3- or more than 3-flowered | 137 |
| 137 | Lower (inner) glume absent on lateral spikelets; spikelets placed with the backs of alternate lemmas to the rachis | Lolium |
| 137* | Both glumes developed; spikelets placed with either the backs of alternate lemmas or with 1 side of all the lemmas to the rachis | 138 |
| 138 | Spikelets 1-flowered, in clusters of 3 at each node of the rachis, the 3 falling together | Hordeum |
| 138* | Spikelets solitary at each node of the rachis | 139 |
| 139 | Spikelets usually with 2 florets, the rachilla often produced above them; glumes narrow, rigid, acuminate or subulate pointed, 1-nerved; lemmas ciliate on the keels, awned | Secale |
| 139* | Spikelets with more than 2 florets | 140 |
| 140 | Glumes very broad, mucronate or toothed or awned, bulging on the back, sometimes keeled above; spikelets 2–5-flowered, placed with 1 side of each of the lemmas against the rachis; lemmas abruptly pointed or awned | Triticum |
| 140* | Glumes not bulging on the back, narrow to moderately broad; spikelets usually more than 5-flowered; lemmas tapering into an awn or awnless | 141 |
| 141 | Lemmas awned, the awn more than 50% the length of the lemma | 142 |
| 142 | Spikelets shortly pedicellate; awns straight; leaf auricles absent; plants annual | Brachypodium |
| 142* | Spikelets sessile; awns often curving away from the lemmas; leaf auricles usually present; plants perennial | Elymus |
| 141* | Lemmas awnless or with an awn or mucro less than 50% the length of the lemma | 143 |
| 143 | Plants strongly rhizomatous; lemmas awnless but may be sharply pointed | Elytrigia |
| 143* | Plants without long rhizomes; lemmas more or less awned | 144 |
| 144 | Rachis of inflorescence 1.5 mm or more wide, glabrous but scabrous or ciliate on the edges; glumes more than 2 mm wide, obtuse | Thinopyrum |
| 144* | Rachis of inflorescence 1 mm or less wide, pubescent; glumes 1.2 mm or less wide, acute | Australopyrum |
| 133* | Spikelets borne in open or contracted spicate panicles; if arranged on opposite sides of the rachis then the lemmas awned or mucronate from a 2-fid apex | 145 |
| 145 | Lemmas usually 5–many-nerved, the nerves never in 3 distinct groups or with the leaves rigid and needle-pointed; plants with non-Kranz anatomy | 146 |
| 146 | Spikelets dimorphic, the fertile and sterile intermixed on the same inflorescence | 147 |
| 147 | Fertile spikelets with 1 bisexual floret, long-awned; sterile spikelets with many obtuse sterile lemmas; small annual with rather dense, somewhat 1-sided, oblong yellowish panicles with crowded groups of spikelets on short drooping branches | Lamarckia |
| 147* | Fertile spikelets 2- or 3-flowered; sterile spikelets with numerous, rigid, awn-tipped lemmas; spikelets borne on 1 side of the main axis of a spicate panicle; annuals or perennials | Cynosurus |
| 146* | Spikelets all alike on the same inflorescence | 148 |
| 148 | Spikelets crowded in 1-sided clusters at the ends of a few, stiffly spreading, naked panicle branches, strongly laterally compressed | Dactylis |
| 148* | Spikelets borne in loose or contracted panicles | 149 |
| 149 | Lemmas as broad as long, cordate at the base with outspread margins, closely overlapping, awnless; panicles loose, spreading or nodding | Briza |
| 149* | Lemmas longer than broad and/or not cordate at the base | 150 |
| 150 | Lemmas laterally compressed and keeled (only slightly so in some species) and often with web-like hairs on the callus; spikelets small, less than 10 cm long; panicles usually loose and spreading at maturity, more rarely somewhat contracted; lodicules free, membranous | 151 |
| 151 | Plants usually less than 1.5 m high; ovary glabrous at apex; hilum punctiform, basal | Poa |
| 151* | Plants often more than 1.5 m high; ovary hairy at the apex; hilum linear-elongate | Dryopoa |
| 150* | Lemmas rounded on the back at least in the lower part, sometimes slightly keeled upwards or spikelets large and more than 10 mm long | 152 |
| 152 | Spikelets shortly but distinctly 3-toothed, the teeth equal or the central 1 mucronate; spikelets about 1.5 cm long, solitary or up to 3 on long capillary branches of a somewhat contracted panicle; lemma prominently nerved | Notochloe |
| 152* | Spikelets obtuse or acute or notched but not obviously 3-toothed | 153 |
| 153 | Nerves of the lemma converging and the lemma narrowed towards the apex | 154 |
| 154 | Ovary with a hairy terminal appendage, the styles arising laterally below it; grain compressed; lemmas usually awned from the minutely notched tip or just behind it | Bromus |
| 154* | Ovary without a hairy terminal appendage, the styles terminal though sometimes inserted rather far apart on the flat top of the ovary | 155 |
| 155 | Perennials; lemmas awned from the entire tip or mucronate or awnless; panicles usually spreading with slender branches | 156 |
| 156 | Lemmas rounded on the back; hilum elongated | Festuca |
| 156* | Lemmas keeled throughout; hilum short, oval | Austrofestuca |
| 155* | Annuals | 157 |
| 157 | Lemmas subulate, tapering into a long awn; glumes very unequal; spikelets few on the usually erect, short, slender branches of a contracted panicle | Vulpia |
| 157* | Lemmas awnless, rather obtuse, 2–2.5 mm long; glumes only slightly unequal; panicle 1-sided, stiff, shortly branched below, the spikelets on short thick pedicels | Catapodium |
| 153* | Nerves of the lemma parallel, not or scarcely converging at the summit, awnless | 158 |
| 158 | Spikelets shortly pedicellate on short dense racemes that may be overtopped by the leaves | Sclerochloa |
| 158* | Spikelets in open or contracted panicles | 159 |
| 159 | Nerves prominent; plants usually rather tall, usually aquatic or semi-aquatic; margins of sheaths fused at least below; lodicules firm, short, truncate, often fused; hilum linear, as long as the grain | Glyceria |
| 159* | Nerves indistinct; plants rather low, usually in saline or alkaline soils or marshes; margins of sheaths free | Puccinellia |
| 145* | Lemmas 1–3-nerved or the nerves in 3 distinct groups and then the leaves rigid and needle-pointed; plants all with Kranz anatomy | 160 |
| 160 | Spikelets more or less densely arranged and very shortly pedicellate on a solitary terminal spike; lemmas awned or mucronate from a 2-lobed apex | Tripogon |
| 160* | Spikelets variously arranged in open or contracted or spicate or interrupted panicles but not in simple spikes | 161 |
| 161 | Lemmas entire, awnless and not produced into awn-like points | 162 |
| 162 | Plants dioecious; perennials with creeping rhizomes; usually on saline soils | Distichlis |
| 162* | Plants monoecious; perennials or annuals, usually without creeping rhizomes; habitats various | 163 |
| 163 | Lemmas 1-nerved, thinly membranous; spikelets borne on the branches of a dense spicate panicle, 2- or 3-flowered | Thellungia |
| 163* | Lemmas 3-nerved, various in texture; spikelets in open or contracted panicles, rarely in racemes or few together in spicate clusters or short branches | Eragrostis |
| 161* | Lemmas distinctly or obscurely notched and then often with a small mucro from the sinus, or awned, or at least truncate and more or less erose and then the spikelets racemose on elongate panicle branches | 164 |
| 164 | Blades hard, stiff, often pungent-pointed, flat or more commonly permanently folded (and then sometimes appearing needle-like); lemmas more or less distinctly 2-toothed or lobed, or emarginate | Triodia |
| 164* | Leaf blades soft or rigid, neither very hard nor pungent-pointed; lemmas various but not 3-lobed or toothed | 165 |
| 165 | Spikelets racemose on elongate branches of the panicle, lemmas truncate and more or less erose or notched and sometimes mucronate but not or scarcely awned | 166 |
| 166 | Lemmas truncate and/or erose or minutely notched, not or scarcely mucronate, lateral nerves often shortly hairy | Leptochloa |
| 166* | Lemmas rather distinctly notched and mucronate, fringed with hairs in the lower part | Diplachne |
| 165* | Spikelets in dense, spicate, sometimes interrupted panicles on their spicate branches; lemmas short- or long-awned or tapering into awn-like points | 167 |
| 167 | Lemmas 3-awned and toothed on either side of the central awn | Triraphis |
| 167* | Lemmas with a single awn or awn-like point | Elytrophorus |
