Key to Keys
	a	Culms woody: bamboos Leaf lamina usually constricted into a pseudo-petiole Flowering erratically (if spikelets unisexual see Olyra)	Key 01 (005)
	b	Culms usually herbaceous Leaf lamina usually not constricted at base into a pseudo-petiole Flowering annually (if perennial, rhizomatous, lawn-forming and inflorescence inconspicuous, enclosed in upper leaf sheath, and of 2-4 spikelets and only anthers and stigmas long-exserted, see Pennisetum clandestinum)

	a	Inflorescence a complex leafy false panicle, spikelet-bearing axis (usually a short raceme) either single or paired, these closely to sparsely subtended by spathes and spatheoles	Key 02 (007)
	b	Inflorescence leafless, spikelet-bearing axis not closely subtended by spathes or spatheoles (sometimes closely associated with uppermost leaf)

	a	Inflorescence of either paired or of 3 to many digitately or subdigitately arranged branches at apex of culm, sometimes enclosed by uppermost leaf at some stage of development If inflorescence in false leafy panicles, then spikelet-bearing axis not obviously or closely associated with leaf-like spathes	Key 03 (025)
	b	Inflorescence not branched, or with spikelet-bearing branches not largely confined to apex of flowering culm

	a	Inflorescence a true spike or spike-like (spikelets or inflorescence branches being so closely packed against the axis to appear like a spike), linear to globose in shape, occasionally spikelet solitary on culm	Key 04 (067)
	b	Inflorescence an open or contracted panicle or raceme or with spike-like primary branches scattered up elongated central axis	Key 05 (254)

Key 01 (Woody bamboos)
	a	Leaf blade strongly cross-veined, forming a tesselate pattern Spikelets not in globose clusters Stamens 3	Thamnocalamus
	b	Leaf blade not strongly cross-veined Spikelets in globose clusters Sstamens 6

	a	Culm sheath blade very broad	*Bambusa
	b	Culm sheath blade narrow	Oxytenanthera

Key 02 (Inflorescence a complex, leafy, false panicle)
	a	Inflorescence branches each subtended by a smooth ivory-like bead or cupule enclosing female spikelets Male spikelets on a tassel exserted from bead Annuals	*Coix
	b	Inflorescence branches not subtended by a smooth ivory-like bead or cupule Annuals or perennials

	a	Spikelet subtended by a bristle	Pennisetum
	b	Spikelet not subtended by a bristle

	a	Upper lemma of sessile spikelet awnless
	b	Upper lemma of sessile spikelet awned or mucronate (sometimes minutely so)

	a	Pedicel of pedicelled spikelet free from rachis
	b	Pedicel of pedicelled spikelet usually discernible but fused with rachis and appearing sessile

	a	Keels of lower glume of sessile spikelet winged Inflorescence rachis joints transverse, internodes clavate Sessile spikelet 4.5-5.0 mm long	Coelorachis
	b	Keels of lower glume of sessile spikelet not winged, (usually with a thick oil streak) Inflorescence rachis joints oblique, internodes columnar to subclavate Sessile spikelet 5-15 mm long	Elionurus

	a	Sessile spikelet globose Lower glume conspicuously pitted or tuberculate Raceme internodes oblong	Hackelochloa
	b	Sessile spikelet elliptic to lanceolate Lower glume smooth Raceme internodes clavate or flattened to semicylindrical

	a	Racemes dorsally compressed, resembling the culm, tough Plants perennial, decumbent or rambling Basal sheaths without irritant hairs Spikelets of a pair similar, especially in sexuality	Hemarthria
	b	Racemes cylindrical, fragile Rrobust annuals, erect Basal sheaths with irritant hairs Spikelets of a pair very dissimilar, especially in sexuality	Rottboellia

	a	Spikelets clustered into triangular units resembling a single spikelet, each unit usually 1-awned, rarely 2- or 3-awned, composed of a single, awned, sessile, bisexual spikelet and two pedicelled spikelets, enclosed by an involucre of 4 sterile sessile spikelets	Themeda
	b	Spikelets not in triangular units resembling a single spikelet

	a	Racemes solitary in spatheoles
	b	Racemes 2 or more in spatheoles

	a	Ligule an unfringed membrane Spatheole boat-shaped, distinct and closely associated with spikelet-bearing axis Sessile spikelet 3.5-4.0 mm long	Monocymbium
	b	Ligule a fringed membrane or a fringe of hairs Spatheole not boat-shaped, closely or not closely associated with spikelet-bearing axis Sessile spikelet 4-20 mm long (rarely 2-3 mm long)

	a	Pedicelled spikelet smaller than sessile spikelet	Schizachyrium
	b	Pedicelled spikelet larger than sessile spikelet

	a	Lower glume of sessile spikelet deeply and narrowly grooved Inflorescence awned all the way At least one glume per spikelet in pair long-awned	Andropogon
	b	Lower glume of sessile spikelet flat or rounded on back Inflorescence awned only in upper part Glumes of both spikelets in pair awnless	Heteropogon

	a	Inflorescence without conspicuous spathes and spatheoles subtending spikelet-bearing axis (low down on flowering culm(s) and closely appressed to inflorescence rachis)
	b	Inflorescence with conspicuous spathes and spatheoles subtending spikelet-bearing axis

	a	Callus of sessile spikelet long, acute to pungent	Diheteropogon
	b	Callus of sessile spikelet short, obtuse or rounded

	a	Pedicel and internodes longitudinally grooved with a translucent median line	Bothriochloa
	b	Pedicel and internodes without a translucent median line

	a	Upper lemma of sessile spikelet 2-lobed, awn from between lobes Internodes of rachis ± cup-shaped on top	Andropogon
	b	Upper lemma of sessile spikelet entire, apex gradually passing into awn Internodes of rachis not cup-shaped	Dichanthium

	a	Awn of upper lemma of sessile spikelet glabrous Plants usually aromatic	Cymbopogon
	b	Awn of upper lemma of sessile spikelet distinctly hairy Plants not aromatic

	a	Lower glume of sessile spikelet flattened to rounded on back Upper glume of sessile spikelet obtuse to acute or mucronate Pedicelled spikelet 3-8(-10) mm long	Hyparrhenia
	b	Lower glume of sessile spikelet with a shallow median groove Upper glume of sessile spikelet acute to apiculate or shortly awned Pedicelled spikelet 9-14 mm long	Hyperthelia

Key 03 (Inflorescence paired, digitate or subdigitate)
	a	Spikelets in triads with pedicels fused, the whole mimicking a single spikelet	Tristachya
	b	Spikelets solitary or 2- to many-nate, pedicels not fused to resemble a single spikelet (one spikelet of a pair may be missing and only represented by an empty pedicel)

	a	Spikelets 2-many-nate (at point of attachment to rachis)
	b	Spikelets solitary (at point of attachment to rachis)

	a	Spikelets all similar Upper lemma usually similar to firmer in texture than glumes Spikelets sessile, subsessile or equally or unequally pedicelled
	b	Spikelet pairs usually dissimilar, if similar, then upper lemma of bisexual spikelet less firm in texture than glumes 1 spikelet usually sessile or subsessile, the other pedicelled (long-short combination), sometimes pedicel without spikelet

	a	Spikelet awnless (glume or lemma sometimes long-acuminate and appearing awned)
	b	Spikelet awned or mucronate (sometimes minutely so)

	a	Upper lemma with narrow, inrolled margins clasping only edges of palea (Paspalum-type)	Paspalum
	b	Upper lemma with flat, thin margins covering most of the palea and often overlapping (Digitaria-type)

	a	Lower glume as long as to slightly longer than spikelet	Megaloprotachne
	b	Lower glume shorter than spikelet or suppressed	Digitaria

	a	Florets 2 per spikelet, lower sterile or male, upper bisexual Spikelet dorsiventrally compressed, falling with glumes
	b	Florets 2 or more per spikelet, lower floret(s) bisexual Spikelet laterally compressed, disarticulating above glumes

	a	Lower glume well developed Upper glume as long as lemma Lower lemma awnless Upper lemma awned, awn robust, shorter than spikelet	Alloteropsis
	b	Lower glume absent Upper glume a minute scale Llower lemma awned, awn fine, longer than spikelet Upper lemma awnless	Stereochlaena

	a	Glumes very unequal in size Bisexual floret 1, rarely 2 per spikelet, rest reduced or sterile	Chloris
	b	Glumes ± equal in size Bisexual florets 2-7 per spikelet, upper reduced or sterile	Tetrapogon

	a	Internodes of rachis and pedicels stout, 3-angled, rounded or flattened and thickened upwards Upper lemma of bisexual spikelet (usually sessile spikelet) awnless
	b	Internodes of rachis and pedicels slender, filiform or linear, sometimes thickened upwards, clavate or substantial, but then upper lemma of bisexual spikelet (usually sessile spikelet) awned

	a	Lower glume of sessile spikelet produced into long awn-like flattened tail Sessile spikelet 20-40 mm long Ligule a fringed membrane	Vossia
	b	Lower glume of sessile spikelet without a long herbaceous tail Sessile spikelet 6-8 mm long Ligule an unfringed membrane

	a	Pedicelled spikelet long-awned (5-120 mm) from lower glume	Urelytrum
	b	Pedicelled spikelet awnless Lower glume of sessile spikelet strongly ridged due to prominent nerves	Phacelurus

	a	Pedicelled spikelet absent, represented only by a flattened, linear pedicel Glumes rugose Coarse annuals Leaf base amplexicaul	Thelepogon
	b	Pedicelled spikelet present Glumes rugose or not Annuals or perennials Leaf base amplexicaul or not

	a	Spikelets unequally pedicelled Subsessile spikelet male or sterile, awnless, long-pedicelled spikelet bisexual, awned	Trachypogon
	b	Spikelets usually 1 sessile and the other pedicelled, with only the sessile spikelet or both spikelets bisexual, awned or awnless

	a	Both spikelets of a pair with at least one lemma with large awn
	b	Usually only sessile spikelet of a pair with at least one lemma with large awn

	a	Spikelet-bearing rachis substantial, clavate or inflated, often appearing U- or V-shaped from the back Sessile or subsessile spikelet with lower palea well developed	Ischaemum
	b	Spikelet-bearing rachis slender Sessile spikelet with lower palea absent or reduced

	a	Lower glume shallowly concave to medianly grooved Spikelets and pedicels glabrous or sparsely hairy Inflorescence open with spikelets loosely spaced Plants rambling or creeping	Microstegium
	b	Lower glume concave to ± flat Spikelets and pedicels hairy Inflorescence dense with spikelets closely spaced Plants tufted	Eulalia

	a	Upper lemma of sessile spikelet entire, gradually passing into awn Callus of sessile spikelet not inserted into hollowed top of internode
	b	Upper lemma of sessile spikelet lobed, awned from between lobes or low down on back Callus of sessile spikelet inserted into hollowed top of internode (if not clear, then pedicels and internodes inflated)

	a	Lower glume of sessile spikelet acute to subacute Pedicels and internodes longitudinally grooved with a translucent median line	Bothriochloa
	b	Lower glume of sessile spikelet obtuse to truncate Pedicels and internodes not grooved, without a translucent median line	Dichanthium

	a	Palea of lower floret of sessile or subsessile spikelet well developed Inflorescence axis usually appears U- or V-shaped from the back	Ischaemum
	b	Palea absent in lower floret of sessile spikelet Inflorescence axis not U- or V-shaped from the back

	a	Callus long, acute to pungent	Diheteropogon
	b	Callus often short, obtuse to truncate

	a	Upper lemma of sessile spikelet awned from between bilobed apex Lower glume of sessile spikelet not spinously muricate Leaf base not markedly cordate Callus obtuse	Andropogon
	b	Upper lemma of sessile spikelet awned from low down on back Lower glume of sessile spikelet spinously muricate Leaf base markedly cordate Callus truncate	Arthraxon

	a	Inflorescence branches not obviously secund
	b	Inflorescence branches obviously secund

	a	Ligule an unfringed membrane Lemma 5-9-nerved, usually with a short stout awn Florets all similar in shape Hairs on lemma clavate and apiculate	Lintonia
	b	Ligule a fringed membrane Lemma 3-nerved, awn slender Upper sterile florets modified to form a tuft of awns Hairs on lemma not clavate	Lophacme

	a	Each inflorescence spike ending in a rigid, naked point	Dactyloctenium
	b	Each inflorescence spike not ending in a naked point

	a	Florets strictly 1 per spikelet, occasionally with a rachilla extension, rarely a vestigial floret present (if lower glume & palea missing and upper glume & lower lemma similar see Axonopus and Paspalum)
	b	Florets 2 or more per spikelet, florets all fertile or mixed, some fertile and others male, sterile or reduced

	a	Lemma awned Awn long and flexuous, becoming entangled with awns of other spikelets	Schoenefeldia
	b	Lemma awnless or mucronate

	a	Spikelet 12-15 mm long Glumes very unequal	Spartina
	b	Spikelet 2.5-5.0 mm long Glumes ± equal to unequal

	a	Glumes shorter than spikelet, rarely as long, but then not enclosing floret	Cynodon
	b	Glumes enclosing spikelet Floret not visible

	a	Spikelet laterally compressed Lower glume symmetrical in shape, both glumes medially keeled Inflorescence branches two	Brachyachne
	b	Spikelet dorsiventrally compressed Lower glume asymmetrically 1-keeled, upper flat on back, 2-keeled Inflorescence branches several	Craspedorhachis

	a	Lemma(s) of bisexual floret(s) awnless, sometimes mucronate
	b	Lemma(s) of bisexual floret(s) awned, awn sometimes minute

	a	Spikelet with 3-15 florets Lemmas similar, sometimes uppermost reduced	Eleusine
	b	Spikelet with 2 florets Lemmas usually dissimilar, rarely 3 florets present, but then second floret male

	a	Lower floret male or reduced, upper floret bisexual (lower glume and lower palea absent, upper glume and lower lemma looking similar)
	b	Lower floret bisexual, upper sterile, reduced or vestigial

	a	Upper lemma with flat, thin margins covering most of the palea and often overlapping (Digitaria-type) Lower palea present	Megaloprotachne
	b	Upper lemma with narrow, inrolled margins clasping only edges of palea (Paspalum-type) Lower palea absent

	a	Spikelet abaxial (lower glume turned away from rachis, upper glume and lemma facing rachis)	Paspalum
	b	Spikelet adaxial (upper glume and lemma turned away from rachis)	Axonopus

	a	Upper glume distinctly awned Spikelets golden to dark brown Sheaths strongly flabellate	Eustachys
	b	Upper glume awnless Spikelets not golden or dark brown Sheaths not strongly flabellate	Cynodon

	a	Lemma rounded or flat on back
	b	Lemma keeled

	a	Spikelet laterally compressed, 6-10 mm long Lemma with short, sharp-pointed to obtuse or club-shaped hairs	Lintonia
	b	Spikelet dorsiventrally compressed, 3-5 mm long Lemma glabrous	Enteropogon

	a	Glumes unequal in size
	b	Glumes ± equal in size (excluding awn)

	a	Upper glume awned, awn up to half as long as body of glume	Eustachys
	b	Upper glume awnless or with an awn point

	a	Lemma of bisexual floret similar to firmer in texture than glumes	Chloris
	b	Lemma of bisexual floret less firm in texture than glumes	Lophacme

	a	Lemma hairy, awn 3-11 mm long Spikelet cuneate Glumes nearly to as long as spikelet Hairy callus present	Tetrapogon
	b	Lemma glabrous, awn 0.3-0.9 mm long Spikelet oblong with serrated outline Glumes much shorter than spikelet Callus absent	Acrachne

Key 04 (Inflorescence a spike or spike-like)
	a	Spikelets solitary on flowering culm
	b	Spikelets many on flowering culm

	a	Florets 5-22 per spikelet, all florets bisexual, or uppermost sterile or reduced	Brachypodium
	b	Florets 3 per spikelet, lower 2 sterile and reduced to lemmas, upper bisexual	Ehrharta

	a	Spikelet or clusters of spikelets enclosed in an involucre of bracts or subtended by 1 to many bristles, spines, scales or bracts, bristle may be solitary, not obvious or hardened to form rigid spines, or inflorescence enclosed by a specialised inflated flag leaf, and the whole falling as a unit
	b	Spikelets not enclosed by an involucre of bracts nor subtended by a bristle or bristles, if enclosed in flag leaf this not specialised and inflorescence not falling as a unit, sometimes enclosed by chaffy and/or enlarged glumes or spathes

	a	Inflorescence enclosed by inflated flag leaf, disarticulating below flag leaf and falling as one unit Glumes and lemmas long-awned Florets 3-7 per spikelet	Tribolium
	b	Spikelet(s) enclosed by an involucre of bracts or a cupule of spines, or subtented by one to many bristles, scales or spines Fflorets 1 or 2 per spikelet

	a	Bristle(s) persisting on axis after spikelet(s) falls	Setaria
	b	Bristle(s), scales, bracts or herbaceous cupule falling with spikelet(s)

	a	Involucre of several sterile spikelets or coriaceous bracts Bristles absent	Anthephora
	b	Involucre of one to many bristles, spines or herbaceous cupules or scales

	a	Involucral bristle, scale or cupule solitary
	b	Involucral bristles or spines several to many

	a	Spikelet subtended by a herbaceous, lobed cupule or scale, one lobe longer and awn-like Stipe supporting spikelet blunt	Odontelytrum
	b	Spikelet subtended by a solitary robust and awn-like or slender bristle Stipe supporting spikelet pungent or absent

	a	Spikelet subtended by a long, pungent stipe Bristle robust and awn-like	Paratheria
	b	Spikelet sessile, not subtended by a stipe Bristle slender	Pennisetum

	a	Bristles free throughout, ± filiform	Pennisetum
	b	Bristles connate and flattened below, forming a disc, sometimes flattened and/or hardened, forming rigid spines enclosing the spikelet	Cenchrus

	a	Inflorescence obviously 1-sided (secund) to subsecund
	b	Inflorescence not obviously secund Spikelets sometimes distichous

	a	Spikelet awnless or mucronate
	b	Spikelets, at least some, awned

	a	Spikelet with 2 florets, lower male or sterile, upper bisexual (lower glume may be minute or absent, upper glume and lower lemma may resemble each other)
	b	Spikelet with 1-many florets, all bisexual or upper male or sterile, or florets 3 with lower 2 sterile and upper bisexual, or if florets 2, then lowest bisexual

	a	Central inflorescence axis thickened Racemes very short (sometimes a single spikelet), embedded in distinct cavities, central axis ending in a subulate tip and without spikelets	Stenotaphrum
	b	Central inflorescence axis not thickened Spikelets or racemes free or in slight cavities

	a	Inflorescence of obvious short racemes scattered singly on alternate sides and appressed to long central axis	Paspalidium
	b	Inflorescence with spikelets solitary, in pairs or triads densely packed on single raceme

	a	Upper lemma of spikelet with flat, hyaline margins enfolding and enclosing most of palea	Digitaria
	b	Upper lemma of spikelet with narrow inrolled margins clasping only edges of palea	Paspalum

	a	Glumes unequal in size
	b	Glumes ± equal in size

	a	Upper glume 1-nerved Floret 1 per spikelet, falling with glumes	Catalepis
	b	Upper glume 3-7-nerved Florets 2-5(-10) per spikelet, disarticulating above glumes

	a	Florets 3, lower 2 sterile, reduced to lemmas	Ehrharta
	b	Florets 2-many, lowest bisexual, upper sometimes reduced

	a	Glumes similar in appearance and/or texture Lemma 5-9-nerved	Tribolium
	b	Glumes dissimilar in appearance and/or texture Llemma 3-nerved	Harpochloa

	a	Ligule an unfringed membrane
	b	Ligule a fringed membrane (fringe sometimes minute) or a fringe of hairs

	a	Florets 3 per spikelet, lower 2 sterile, upper bisexual, usually smaller than lower 2 Lower glume 5-nerved	Ehrharta
	b	Florets 3-10 per spikelet, all bisexual except uppermost reduced and sterile Lower glume 1-3-nerved	*Catapodium

	a	Floret 1 per spikelet
	b	Florets 2 or more per spikelet

	a	Spikelet dark, usually brown or purple, not noticeably to dorsiventrally compressed Lemma 2-nerved	Microchloa
	b	Spikelet light-coloured, golden brown, strongly laterally compressed Lemma 3-nerved	Brachyachne

	a	Florets 4-10 per spikelet	Tribolium
	b	Florets 2 or 3 per spikelet

	a	Florets 3 per spikelet, lower 2 sterile, usually dissimilar from upper bisexual floret	Ehrharta
	b	Florets 2 per spikelet, lower bisexual, upper bisexual or sterile

	a	Annuals Spikelet laterally compressed Glumes 5-8-nerved	Prionanthium
	b	Perennials Lower glume obliquely compressed, upper glume dorsiventrally compressed Glumes 1-nerved	Rendlia

	a	Ligule an unfringed membrane Spikelets dissimilar, bisexual ones mixed with sterile or male ones on same inflorescence
	b	Ligule a fringe of hairs or a fringed membrane, (fringe sometimes minute) Spikelets all similar in sexuality on inflorescence

	a	Inflorescence soft and silky Spikelet cluster of 2 or 5 sterile spikelets with a terminal bisexual spikelet, clusters fall as a whole Spikelet bisexual with one fertile and one sterile floret Male or sterile spikelets with awnless lemmas	*Lamarckia
	b	Inflorescence appearing bristly Spikelet cluster of 1 or more sterile spikelets mixed with bisexual spikelets consisting of (1)2 or 3 florets, clusters do not fall as a whole, spikelets disarticulating above glumes Sterile spikelets with glumes and lemma bearing long rigid awns	*Cynosurus

	a	Upper glume with an oblique dorsal awn well below apex, 2- or 3-nerved, nerves with tubercles Lower 2 florets male or sterile	Ctenium
	b	Upper glume awned from near apex or awnless, 1-nerved or 5-7-nerved, nerves not tubercled Lower florets bisexual, upper floret usually reduced and sterile

	a	Glumes ± equal in size Spikelet cuneate	Tetrapogon
	b	Glumes unequal in size Spikelet elliptic-oblong to lanceolate or linear-elliptic

	a	Spikelet dorsiventrally compressed Inflorescence secund Plants tall robust usually 500 mm high or higher	Enteropogon
	b	Spikelet laterally compressed Inflorescence subsecund Plants slender up to 220 mm high	Tripogon

	a	Ligule absent from upper or all leaves
	b	Ligule present on all leaves

	a	Spikelets densely and irregularly crowded on inflorescence Spikelet softly long-hairy	Brachiaria
	b	Spikelets in regular rows on inflorescence Spikelet minutely soft-hairy or with long, rigid hairs	Echinochloa

	a	Bisexual spikelet with 1 floret (rachilla extension sometimes present)
	b	Bisexual spikelet with 2-many florets (some florets may be reduced to lemmas or differ in size and shape)

	a	Ligule an unfringed membrane
	b	Ligule a fringed membrane or a fringe of hairs

	a	Some or all spikelets awned
	b	All spikelets awnless or mucronate

	a	Spikelets in triads, central spikelet bisexual, two lateral spikelets male or sterile Central spikelet with one floret, rachilla extension present Glumes side by side	Hordeum
	b	Spikelets not in triads, or if in triads then all spikelets alike in function Glumes not displaced

	a	Glumes swollen and rounded on back near base	*Gastridium
	b	Glumes not swollen or rounded on back

	a	Spikelets falling entire with the glumes
	b	Spikelets disarticulating above the glumes

	a	Inflorescence a contracted panicle Lemma 5-nerved	Polypogon
	b	Inflorescence a cylindrical spike or spike-like raceme Lemma 1-nerved	Perotis

	a	Glumes plumose with long silky hairs Inflorescence globose to ovoid	*Lagurus
	b	Glumes glabrous or hairy, not plumose with long silky hairs Inflorescence linear

	a	Lemma awn very long and extending beyond glumes, awn apical or from sinus Lemma becoming indurated	Stipa
	b	Lemma awn short, not extending beyond glumes, awned from well below apex or at base Lemma not becoming indurated

	a	Callus glabrous or with hairs up to half as long as lemma Spikelet up to ± 5 mm long	Agrostis
	b	Callus beaded with long white hairs as long as to longer than lemma Spikelet 5.5-8.0 mm long	Calamagrostis

	a	Glumes longer than 10 mm	*Ammophila
	b	Glumes 1-8 mm long

	a	Inflorescence with spikelets alternating on opposite sides and sunk in rachis Annuals
	b	Inflorescence with many spikelets all around, not sunk into rachis Perennials, sometimes annuals

	a	Glumes 1, lower suppressed (terminal spikelets with 2)	*Hainardia
	b	Glumes 2 but displaced, side by side	*Parapholis

	a	Inflorescence a contracted panicle Spikelet pedicelled, disarticulating above glumes Glumes similar in shape and/or texture Lemma 3-5-nerved	Agrostis
	b	Inflorescence a dense spike Spikelet sessile, falling with glumes Glumes very dissimilar in shape and/or texture, upper glume flat-backed Lemma 1-3-nerved	Mosdenia

	a	Spikelet awned or mucronate (sometimes minute)
	b	Spikelet neither awned nor mucronate

	a	Lemma 1-3-awned
	b	Lemma mucronate or muticous

	a	Lemma 1-awned
	b	Lemma 3-awned (due to fusion of the lower parts of the awns into a column, it may be seen as one awn with 3 branches)

	a	Lower glume a minute membranous scale Lemma less firm in texture than glumes	Monelytrum
	b	Lower glume well developed Lemma firmer in texture than glumes, usually becoming indurated

	a	Ligule a fringed membrane Lemma articulation never present	Stipa
	b	Ligule a dense fringe of hairs Lemma articulation usually present (absent in Aristida transvaalensis)

	a	Base of column with a pencil of long white hairs Callus pungent	Stipagrostis
	b	Base of column glabrous Callus obtuse to truncate to rounded	Aristida

	a	Lemma distinctly 2-lobed, lobes awned with long straight awns Central awn geniculate	*Lagurus
	b	Lemma not appearing lobed, awns coming off ± together at apex, similar though lateral awns may be shorter Column present or absent

	a	Lemma awns all or only centre awn plumose Palea indurated	Stipagrostis
	b	Lemma awns all glabrous, smooth or scabrid Palea not indurated

	a	Upper glume 3-5-nerved Lower glume usually 3-nerved Glumes rounded on back Awns spirally contorted at base Caryopsis deeply grooved ventrally	Sartidia
	b	Upper glume 1(3)-nerved Lower glume nearly always 1-nerved Glumes 1-keeled to middle or below Awns not spirally contorted at base Caryopsis not deeply grooved	Aristida

	a	Spikelets ± embedded on central axis
	b	Spikelets not embedded on central axis (sometimes appressed)

	a	Plant stoloniferous Leaves mainly cauline Spikelet dorsiventrally compressed, 8-22 mm long Upper glume awned	Lepturus
	b	Plant densely tufted, not stoloniferous Leaves mainly basal Spikelet laterally compressed, 2.5-4.5 mm long Upper glume awnless	Oropetium

	a	Glumes awnless Inflorescence oblong Spikelet disarticulating above glumes	Polevansia
	b	Glumes (or at least one) awned Inflorescence linear Spikelet disarticulating with glumes	Perotis

	a	Upper glume with large, hooked, curved or straight prickles, 5-7-nerved Spikelets dorsiventrally compressed Lower glume absent or a minute scale	Tragus
	b	Upper glume without hooked, curved or long, straight prickles, 1-nerved Spikelet laterally to not noticeably compressed Lower glume substantial or reduced to a scale

	a	Lower glume substantial Lemma glabrous	Sporobolus
	b	Lower glume small or reduced to a linear scale Lemma hairy, hairs in tufts or lines on either side of keel	Catalepis

	a	Ligule an unfringed membrane
	b	Ligule a fringed membrane (fringe sometimes minute) or a fringe of hairs

	a	Spikelets viviparous, mainly upper florets distorted and enlarged	Poa
	b	Spikelets usually not viviparous

	a	All spikelets awnless and not mucronate
	b	All or some spikelets awned or mucronate

	a	Spikelets in pairs, one sessile and the other pedicelled, dissimilar in form and sex Pedicelled spikelet very reduced or absent and pedicel empty	Rhytachne
	b	Spikelets solitary or clustered, if paired, spikelets all similar in form and sex

	a	Glumes ± equal in size
	b	Glumes unequal in size, sometimes lower one reduced or absent (terminal spikelets often have both glumes well developed)

	a	Florets 2 or 3 per spikelet Lowest 1 or 2 florets sterile or reduced to lemmas, upper floret bisexual
	b	Florets 2-many per spikelet Lowest floret bisexual, upper sometimes sterile or reduced

	a	Spikelet with 2 florets	Tarigidia
	b	Spikelet with 3 florets

	a	Glumes 5-nerved Lower 2 sterile florets usually larger than upper bisexual floret	Ehrharta
	b	Glumes 3-nerved Lower 2 sterile florets very small to more than half as long as the larger upper bisexual floret	*Phalaris

	a	Spikelet (15-)28-40 mm long Inflorescence a true spike Spikelet falling with glumes	Thinopyrum
	b	Spikelet 1.0-15.0 mm long Inflorescence a contracted panicle or raceme Spikelet disarticulating above glumes

	a	Spikelet 10-15 mm long Upper sterile spikelets compacted to form a club-shaped body on prolonged rachis	Melica
	b	Spikelet 1-7 mm long Upper spikelets, if sterile, not forming a club-shaped body

	a	Spikelet 1-3 mm long Lemma 3-nerved	Diandrochloa
	b	Spikelet 3-7 mm long Lemma 3-7(-11)-nerved, if 3 mm long, lemma 5-nerved

	a	Palea of mature spikelet projecting, thinner in texture than lemma Spikelet shining	Koeleria
	b	Palea of mature spikelet not projecting, same texture as lemma Spikelet not shining	Poa

	a	Florets 3, lower 2 sterile, usually different and larger than upper bisexual floret	Ehrharta
	b	Florets 2 or more, all bisexual or upper or lowermost ones reduced and sterile

	a	Inflorescence a spike Spikelets sunk into partial cavities on alternate sides of central axis Lower glume absent or rarely minute (present in terminal spikelet) Upper glume facing outwards
	b	Inflorescence a contracted raceme or panicle, branches appressed, not sunk into central axis Lower glume usually present, sometimes reduced in size

	a	Spikelet laterally compressed Disarticulating above glumes Lemma 5-7-nerved (best seen on inner surface)	*Lolium
	b	Spikelet dorsiventrally compressed, falling with glumes Lemma 3-nerved	Lepturus

	a	Spikelet with 2 florets Upper lemma indurated Upper glume prominently nerved, usually gibbous Inflorescence mostly cylindrical	Sacciolepis
	b	Spikelet with 2 or more florets No lemma indurated Upper glume never gibbous Inflorescence not cylindrical

	a	Spikelet 1-3 mm long (lemma 3-nerved, if 5-nerved see Poa)	Diandrochloa
	b	Spikelet 4-20 mm long

	a	Lemma without median keel, usually rounded on back, at least at base
	b	Lemma with medium keel

	a	Lemma glabrous or shortly hairy Upper floret similar in form, sometimes reduced in size	Festuca
	b	Lemma with long hairs Upper florets reduced to lemmas compacted to form a club-shaped body	Melica

	a	Palea of mature spikelet projecting Spikelet shining	Koeleria
	b	Palea of mature spikelet not projecting Spikelet not shining	Poa

	a	Spikelets in triads, central spikelet well developed, bisexual, 2 lateral spikelets male or sterile, smaller or reduced (sometimes reduced to awns)	Hordeum
	b	Spikelets solitary, in pairs or in clusters, spikelets all similar or pairs sometimes dissimilar in form and sex

	a	Spikelets in pairs, these dissimilar in form and sex, sometimes some pairs on inflorescence similar
	b	Spikelets solitary, in clusters or in pairs, all spikelets similar in form and sex on inflorescence

	a	Pedicelled spikelet with lower glume drawn out into an awn 5-120 mm long Lemmas of all spikelets awnless	Urelytrum
	b	Pedicelled spikelet with lower glume awnless or with a short awn up to 5 mm long, or entire spikelet reduced to an awn Lemmas of the sessile and/or pedicelled spikelets awned (except in Rhytachne where lemmas are awnless)

	a	Awn short, straight Internodes clavate	Rhytachne
	b	Awn long, not straight, usually geniculate Internodes linear

	a	Long-pedicelled spikelet bisexual Upper lemma long-awned Subsessile spikelet male or sterile, usually awnless Spikelet pairs usually similar along whole length of raceme	Trachypogon
	b	Pedicelled spikelet male or sterile, awnless Sessile spikelet bisexual, upper lemma awned

	a	Inflorescence a panicle of numerous long racemes in whorls up long central axis Spikelets not in homogamous pairs	Bothriochloa
	b	Inflorescence a single raceme Spikelet pairs in lower parts of raceme homogamous (alike in sex and shape), those in upper parts heterogamous (differing in sex and shape)	Heteropogon

	a	Spikelets in clusters, clusters often ± subtended by enlarged spreading glumes of lower spikelets	Elytrophorus
	b	Spikelets solitary, paired or clustered, not subtended by glumes of lower spikelets

	a	Florets 3 per spikelet Lower 2 male or sterile Upper bisexual, awnless
	b	Florets 2 to many per spikelet Llowest usually bisexual, sometimes male Upper sometimes sterile and reduced, awned or awnless

	a	Lemma awns dissimilar - > lowest lemma awned from upper half, awn usually straight Second lemma awned from near base, awn usually geniculate	Anthoxanthum
	b	Lemma awns similar in position and type	Ehrharta

	a	Florets 2 Lower lemma awnless Upper lemma awned with a short stout awn, awn sometimes recurved and hooked	Holcus
	b	Florets 2 to many, all similar, sometimes upper reduced or only lower florets awned

	a	Lower glumes absent in all spikelets (except terminal one), upper glume turned outwards Spikelets partially sunk in cavities, obviously distichous on inflorescence	*Lolium
	b	Lower glumes present in all spikelets, but sometimes very reduced

	a	Glumes ± as long as to longer than spikelet
	b	Glumes shorter than spikelet, at least lower glume much shorter (in Helictotrichon galpinii glumes just shorter than spikelet)

	a	Spikelet mucronate or minutely awned Palea hyaline, projecting and conspicuous in mature spikelets	Koeleria
	b	Spikelet with obvious awn Palea not projecting from mature spikelet

	a	Inflorescence a spike Spikelet 10-15 mm long, long-awned	Secale
	b	Inflorescence a contracted panicle or branches scattered along central axis Spikelet 2-11 mm long, short-awned

	a	Inflorescence a dense, contracted panicle Upper glume 3-nerved	*Lophochloa
	b	Inflorescence of numerous branches scattered up central axis Upper glume 1-nerved	Trichoneura

	a	Awns geniculate or bent, often twisted
	b	Awns straight or mucro present

	a	Lower lemma awned from between lobes Lowest floret bisexual	Helictotrichon
	b	Lower lemma awned from lower third of back Lowest floret usually male	*Arrhenatherum

	a	Spikelet 2-6 mm long
	b	Spikelet 7-44 mm long

	a	Lemma bilobed Awns obvious Annuals	*Lophochloa
	b	Lemma entire Aawns not obvious Perennials, rarely annuals

	a	Palea thinner in texture than lemma, obvious in mature spikelet	Koeleria
	b	Palea similar in texture to lemma, not obvious in mature spikelet	Poa

	a	Inflorescence a spike
	b	Inflorescence a condensed panicle or single raceme

	a	Spikelet 10-20 mm long	*Elytrigia
	b	Spikelet (15)28-40 mm long	Thinopyrum

	a	Lemma awn very short	Festuca
	b	Lemma awn long

	a	Lower glume 0- or 1-nerved
	b	Lower glume 3-9-nerved

	a	Glumes ± similar in form and texture Ovary with apical appendage	Bromus
	b	Glumes dissimilar in form and texture Ovary glabrous or hairy, without apical appendage	*Vulpia

	a	Inflorescence a panicle (rarely a raceme) Ovary with apical appendage	Bromus
	b	Inflorescence a raceme with spikelets on opposite side of rachis Ovary without apical appendage	Brachypodium

	a	All or some spikelets awned or mucronate
	b	All spikelets muticous

	a	Lemma margins lobed Lobes with large flat awns, median lobes sometimes with smaller awns Lemma becoming distinctly indurated, apex between marginal nerves bent forward Glumes 9-11-nerved	Kaokochloa
	b	Characters not in above combination

	a	Lemma 5- or 9-awned
	b	Lemma 1-3-awned or mucronate (at least one lemma)

	a	Lemma 5-awned, awns scabrid, alternating with hyaline lobes	Schmidtia
	b	Lemmas 9-awned, awns plumose or scabrid, not alternating with hyaline lobes	Enneapogon

	a	Spikelets paired, usually dissimilar in sex and form (heterogamous), often one sessile and the other pedicelled (pedicel sometimes fused to rachis but discernable)
	b	Spikelets solitary, clustered or paired, all similar in sex and form

	a	Upper lemma of sessile spikelet awnless
	b	Upper lemma of sessile spikelet awned or mucronate

	a	Sessile spikelet hairy to sparsely hairy Lower glume with oil streaks along keels Inflorescence obvious Pedicels free	Elionurus
	b	Sessile spikelet glabrous Lower glume without oil streaks along keel Inflorescence culm-like Pedicels fused	Hemarthria

	a	Sessile spikelet 9-15 mm long Upper palea well developed	Sehima
	b	Sessile spikelet 2.5-9.0(-11) mm long Upper palea reduced or absent

	a	Inflorescence a panicle of numerous long racemes in whorls on a long central axis Lower glume of sessile spikelet usually with 1-3 pits	Bothriochloa
	b	Inflorescence a single raceme Lower glume of sessile spikelet without pits

	a	Inflorescence with up to three-quarters of lower part with homogamous, awnless spikelet pairs Upper lemma of sessile spikelet entire	Heteropogon
	b	Inflorescence with spikelet pairs usually similar along whole length of raceme Upper lemma of sessile spikelet usually 2-lobed	Schizachyrium

	a	One or more lemmas with median awn geniculate or at least twisted in lower part
	b	One or more lemmas mucronate or with a straight median awn

	a	Glumes unequal in size
	b	Glumes ± equal in size

	a	Ligule a fringed membrane	Arundinella
	b	Ligule a fringe of hairs

	a	Lemma hairs in tufts or fringes or in tufts mixed with dispersed hairs	Danthoniopsis
	b	Lemma glabrous or with dispersed hairs	Loudetia

	a	Spikelet with 2 florets
	b	Spikelet with 3 to many florets

	a	Florets dissimilar in form Upper floret specialised male or sterile Lemma awned with stout hooked awn Lower lemma awnless Upper glume awned	Holcus
	b	Florets similar in form Both similarly awned or lower lemma awnless Upper glume awnless

	a	Lemma 6-16 mm long, lobes usually with short fine awns	Merxmuellera
	b	Lemma 2.0-5.8 mm long, lobes usually with long stout awns

	a	Articulation on pedicel situated some distance below spikelet and bearded with long hairs Spikelet falling with glumes	Chaetobromus
	b	Articulation not present on pedicel Spikelet disarticulating above glumes	Pentaschistis

	a	Spikelet 4-7 mm long	Karroochloa
	b	Spikelet 7.5-25.0 mm long

	a	Articulation on pedicel situated some distance below spikelet and bearded with long hairs Spikelet falling with glumes	Chaetobromus
	b	Articulation not present on pedicel Spikelet disarticulating above glumes

	a	Glumes prominently 7-11-nerved Callus pungent	Centropodia
	b	Glumes 1-5(7)-nerved Callus rounded or long, narrowly obtuse

	a	Glumes 1-keeled to middle or below Palea similar in texture to lemma	Merxmuellera
	b	Glumes rounded, flat or with more than 1 keel Palea thinner than lemma	Dregeochloa

	a	Spikelet with 2 or 3 florets, lower 1 or 2 florets male or sterile, uppermost bisexual
	b	Spikelet with 2 to many florets Lowest floret bisexual Upper bisexual or sterile, or with lower and upper florets sterile and remaining bisexual

	a	Florets 3 Upper glume and lower lemmas dissimilar Lower glume well developed, 5-nerved Lower two lemmas specialised, usually larger and different from upper lemma	Ehrharta
	b	Florets 2 Upper glume and lower lemma often similar Lower glume often reduced, 0-3-nerved Lower lemma usually shorter than to as long as upper lemma

	a	Inflorescence a contracted panicle	Melinis
	b	Inflorescence of racemes scattered along central axis

	a	Glumes unequal Lower glume acute to acuminate, often mucronate	Echinochloa
	b	Glumes ± equal Lower glume long-awned	Oplismenus

	a	Glumes obviously much shorter than spikelet
	b	Glumes (at least upper glume) ± as long as to much longer than spikelet

	a	Lower glume 3-7-nerved
	b	Lower glume 1-nerved

	a	Lemma emarginate to well-lobed
	b	Lemma entire

	a	Lower glume 3-nerved Glumes coriaceous to subcoriaceous	Brachychloa
	b	Lower glume 5-7-nerved Glumes membranous	Schismus

	a	Spikelet spiny due to stout deflexed awns of lemmas Fertile lemma firmer in texture than glumes	Entoplocamia
	b	Spikelet not spiny, awns slender Fertile lemma less firm than, to similar in texture to glumes

	a	Lemma glabrous Spikelet 10-44 mm long	Brachypodium
	b	Lemma hairy Spikelet 1.5-7.0(-10) mm long	Tribolium

	a	Inflorescence a solitary spike Spikelets borne alternately up along rachis	Tripogon
	b	Inflorescence a panicle or raceme with branches closely appressed to or stiff and at right angles to central axis, or with dense clusters of spikelets at intervals on central axis

	a	Lemma glabrous (rarely with tubercle-based hairs on side nerves)
	b	Lemma hairy

	a	Glumes sparsely hairy	Elytrophorus
	b	Glumes glabrous

	a	Lemma 5-7-nerved	Brachychloa
	b	Lemma 3-nerved

	a	Lemma lanceolate to ovate-lanceolate Inflorescence resembling a herring bone due to many stiff side branches	Pogonarthria
	b	Lemma ovate, elliptic to oblong Inflorescence not resembling a herring bone	Eragrostis

	a	Lemma deeply lobed, 3-awned
	b	Lemma entire or not deeply lobed, 1-awned or mucronate

	a	Lemma with lateral nerves glabrous or minutely hairy Glumes 3-lobed or entire Base of plant with dense fibrous sheaths	Styppeiochloa
	b	Lemma with lateral nerves long-hairy Glumes usually 2-lobed Base of plant without fibrous sheaths	Triraphis

	a	Leaf blades short, distichous, pungent Perennials	Odyssea
	b	Leaf blades not pungent Annuals

	a	Lemma mucronate
	b	Lemma awned

	a	Glumes glabrous to minutely scaberulous	Brachychloa
	b	Glumes densely hairy with tubercle-based hairs	Stiburus

	a	Inflorescence silky Leaves broad, lanceolate to ovate Glumes very unequal	Leptocarydion
	b	Inflorescence bristly Leaves narrow, linear Glumes ± equal to slightly unequal	Elytrophorus

	a	Lower glume 1- or 2-nerved
	b	Lower glume 3-11-nerved

	a	Inflorescence of short, stiff spikes spaced up to 30 mm apart, ascending at first, reflexing at maturity	Dinebra
	b	Inflorescence dense and continuous or of dense, globose clusters at intervals on central axis

	a	Glumes with tubercle-based hairs	Stiburus
	b	Glumes glabrous or hairy, hairs not tubercle-based

	a	Annual hydrophytes	Elytrophorus
	b	Perennials, rarely annuals but then not hydrophytic

	a	Spikelet 1-3 mm long	Chloris
	b	Spikelet 4-25 mm long

	a	Lemma keeled Spikelet strongly laterally compressed	Fingerhuthia
	b	Lemma rounded on back Spikelet not strongly laterally compressed	Merxmuellera

	a	Articulation on pedicel situated some distance below spikelet and bearded with long hairs Spikelet falling with glumes	Chaetobromus
	b	Articulation not present on pedicel Spikelet disarticulating above glumes

	a	Glumes with keels usually with large, prominent, stalked glands	Prionanthium
	b	Glumes with keels eglandular or glands not prominent or stalked

	a	Spikelet 9-13 mm long	Merxmuellera
	b	Spikelet 1.5-7.0(-10) mm long

	a	Lemma lobed or emarginate	Schismus
	b	Lemma entire, rarely minutely emarginate	Tribolium

	a	Spikelets in pairs, usually one sessile and the other pedicelled, these differing in form and sex, sometimes unequally pedicelled and similar in form and sex Pedicels free or fused and ± discernible
	b	Spikelets apparently solitary, in pairs or clusters, similar in form and sex

	a	Annuals Internodes fused to adjacent pedicels, pedicels hardly discernible Basal sheaths usually with irritant hairs	Rottboellia
	b	Perennials Pedicels discernable Basal sheaths without irritant hairs

	a	Inflorescence of a number of branches ± appressed to central axis Callus with tawny hairs half as long as to longer than spikelet	Eriochrysis
	b	Inflorescence a single raceme Hairy callus present or absent, hairs white to silver, usually less than half as long as spikelet

	a	Lower glume winged, without oil streaks along keels Spikelet and callus glabrous Rachis joints transverse Callus truncate, with peg	Coelorachis
	b	Lower glume wingless, usually with oil streaks along keels Spikelet and callus hairy (sometimes sparsely so) Rachis joints oblique Callus cuneate, without peg	Elionurus

	a	Inflorescence white to silvery due to long silky hairs from callus and glumes which almost conceal spikelets	Imperata
	b	Inflorescence glabrous or hairy, hairs not long and silky, not concealing spikelets

	a	Lower 1 or 2 florets sterile, male or reduced Upper floret bisexual
	b	Florets 2-many, all bisexual or upper reduced

	a	Florets 3 per spikelet
	b	Florets 2 per spikelet

	a	Lower sterile florets usually larger than upper bisexual floret, sometimes lowest floret very small and reduced Glumes 5-nerved	Ehrharta
	b	Lower sterile florets very small to more than half as long as upper bisexual floret Glumes 3-nerved	*Phalaris

	a	Inflorescence a single cylindrical raceme Spikelets sunk into rachis Upper bisexual lemma less firm in texture than glumes	Oxyrachis
	b	Inflorescence a contracted panicle or a number of racemes scattered up along central axis (racemes, not spikelets, may be sunk into central axis) Upper bisexual lemma usually similar to, to firmer in texture than glumes

	a	Upper lemma hairy	Entolasia
	b	Upper lemma glabrous

	a	Inflorescence of a number of racemes scattered up along central axis
	b	Inflorescence a contracted panicle, sometimes cylindrical

	a	Spikelet glabrous, abaxial to rachis	Paspalidium
	b	Spikelet hispid or hispidulous, adaxial to rachis	Echinochloa

	a	Upper glume and lower lemma hairy, hairs in tufts or fringes Upper glume not gibbous Spikelet 7 mm long	Leucophrys
	b	Upper glume and lower lemma glabrous Upper glume gibbous Spikelet 1.3-4.5 mm long	Sacciolepis

	a	Glumes shorter than spikelet
	b	Glumes as long as to longer than spikelet

	a	Glumes 1-nerved, rarely 3-nerved Lemma 3-nerved
	b	Glumes 3-7-nerved Lemma 5-9-nerved

	a	Plants prickly
	b	Plants not prickly

	a	Plant woody Central axis of inflorescence very stout and stiff, resembling culms, often ending in a pungent point, inflorescence sparse Lemma glabrous or very shortly hairy Glumes ± equal	Cladoraphis
	b	Plants not woody Inflorescence not very stout and stiff usually ending in a spikelet or soft point, inflorescence dense Lemma with silky hairs on lower part of nerves Glumes unequal	Odyssea

	a	Lemma hairy all over with long hairs	Stiburus
	b	Lemma glabrous or hairs present on nerves only

	a	Lemma lanceolate to ovate-lanceolate Inflorescence resembling a herring bone due to numerous stiff side branches	Pogonarthria
	b	Lemma ovate, elliptic to oblong Inflorescence not resembling a herring bone	Eragrostis

	a	Lemma lobed or emarginate	Schismus
	b	Lemma entire, rarely emarginate	Tribolium

	a	Florets 2 per spikelet
	b	Florets 3-many per spikelet

	a	Lower glume 1-nerved
	b	Lower glume 3-8-nerved

	a	Lemma entire, keeled Glumes minutely to long-hairy on keels	Fingerhuthia
	b	Lemma lobed, rounded on back Glumes glabrous or puberulous all over	Pentaschistis

	a	Glumes rounded at apex	Prionanthium
	b	Glumes acute to acuminate at apex	Tribolium

	a	Spikelet strongly laterally compressed Glumes 1-nerved	Fingerhuthia
	b	Spikelet laterally to not noticeably compressed Glumes 3-7-nerved

	a	Lemma lobed or emarginate	Schismus
	b	Lemma entire, rarely emarginate	Tribolium

Key 05 (Inflorescence a panicle or raceme, or with spike-like branches scattered up the central axis)
	a	Lemma 5- or more-awned
	b	Lemma awnless, or less than 5-awned

	a	Lemma with two side nerves produced into large flat awns, other nerves excurrent into smaller awns Lemma not deeply cleft, becoming distinctly indurated Callus absent Palea apically notched	Kaokochloa
	b	Lemma nerves excurrent into thin awns or awns alternating with awnless lobes, awns not large and flat Lemma deeply cleft, not becoming indurated Callus short Palea entire

	a	Lemma 5-awned, awns scabrid, alternating with hyaline lobes	Schmidtia
	b	Lemmas 9-awned, awns plumose or scabrid, not alternating with hyaline lobes	Enneapogon

	a	Leaf blade with cross venation (usually more conspicuous on lower surface)
	b	Leaf blade without obvious cross venation

	a	Inflorescence of 2-6 racemes or fascicles of spikelets scattered up central axis Florets 2, lower floret sterile or male, upper floret bisexual
	b	Inflorescence an open or contracted panicle Florets 1-many, all bisexual or upper reduced and sterile

	a	Lower glume awnless Upper glume gibbous, longer than spikelet	Pseudechinolaena
	b	Lower glume awned Upper glume not gibbous, shorter than spikelet	Oplismenus

	a	Leaf blade pseudopetiolate Male and female spikelets on same inflorescence (males below females, or on lower parts of panicle) Female spikelets with 1 floret, lower glume drawn out into an awn up to 20 mm long Male spikelets with lemma awned Plants woody	Olyra
	b	Leaf base not pseudopetiolate Spikelets all alike on inflorescence Glumes and lemmas awnless or with short mucro or awn Plants herbaceous

	a	Florets many per spikelet Florets all alike in function or upper sterile, often smaller Upper glume 3- or 4-nerved Lemma shortly 2-lobed or emarginate, not becoming indurated Spikelet laterally compressed	Megastachya
	b	Floret 2 per spikelet Lower floret male or sterile, upper floret bisexual Upper glume 5-nerved Upper lemma entire, indurated, shining	Panicum

	a	Ligule absent Florets 2 per spikelet, upper lemma indurated	Echinochloa
	b	Ligule present (may be absent in some leaves) Florets 1-many, upper lemma may or may not be indurated

	a	Ligule an unfringed membrane (sometimes minutely or sparsely ciliolate or fimbriate)
	b	Ligule a fringe of hairs or a fringed membrane

	a	Spikelet unconventional and hard to interpret Glumes absent or very reduced or specialised
	b	Spikelet conventional Glumes, at least upper one, usually present

	a	Florets apparently 1 per spikelet (sterile lemmas suppressed) Glumes absent or reduced to rim, lemma boat-shaped, keels rigidly ciliate	Leersia
	b	Florets 3 per spikelet Lower florets sterile and reduced to lemmas Glumes absent or very reduced or joined, forming a cup

	a	Bisexual floret with lemma not strongly keeled, membranous to chartaceous Leaves heterophyllous, some leaves clinging by retrosely scabrid blade margins Climbing forest grasses Lemma awnless Caryopsis longitudinally grooved	Prosphytochloa
	b	Bisexual floret with lemma strongly keeled, coriaceous Leaves not heterophyllous Not climbing forest grasses Lemma long-awned (awn 10-160 mm long) Caryopsis not grooved	Oryza

	a	Floret 1 per spikelet
	b	Florets 2 or more per spikelet

	a	Glumes shorter than spikelet
	b	Glumes ± as long as to longer than spikelet

	a	Lemma awnless Spikelet 2.5-4.0 mm long Rachilla extension not present Plants of wet areas in high altitude grassland	Colpodium
	b	Lemma awned, awn long and straight Spikelet 7-9 mm long Rachilla extension present Forest grass	Festuca

	a	Lemma less firm to similar in texture to glumes, not becoming indurated Lemma awnless, mucronate or awned Awn slender
	b	Lemma firmer in texture than glumes, becoming indurated Lemma awnless, mucronate or awned, awn robust

	a	Spikelet 5.5-8 mm long Callus beaded with conspicuous white hairs longer than lemma Plant tall, robust	Calamagrostis
	b	Spikelet up to 5.5 mm long Callus absent, if present, then glabrous or hairy, hairs inconspicuous, up to half as long as lemma Plant small, slender

	a	Spikelet falling with glumes Lemma awnless or awned, central awn arising at or near apex	Polypogon
	b	Spikelet disarticulating above glumes Lemma awnless or awned, central awn arising well below apex or at base

	a	Inflorescence a panicle with spikelets not secund on branches Lemma not keeled	Agrostis
	b	Inflorescence of one-sided racemes scattered along central axis due to spikelets being secund on branches Lemma keeled	Leptochloa

	a	Lemma margins strongly and firmly overlapping, lemma thick and stiff Palea a third or less of length of lemma, hyaline, glabrous, nerveless Asymmetrically awned Spikelet gibbous	*Nassella
	b	Lemma margins slightly overlapping, involute or open, lemma thickly membranous to coriaceous Palea at least half as long as lemma, pubescent or glabrous, usually 2-nerved Awn central Spikelet not gibbous	Stipa

	a	Florets 2 per bisexual spikelet Rachilla extension present or absent
	b	Florets more than 2 per bisexual spikelet

	a	Spikelets paired (terminal spikelets often in triads), usually dissimilar in function, one sessile and the other pedicellate, sometimes pedicel without a spikelet, or spikelets unequally pedicelled
	b	Spikelets solitary, paired or in groups, all similar in function

	a	Lower glumes with 1-3 pits Pedicels and internodes longitudinally grooved with a translucent median line	Bothriochloa
	b	Lower glume without pits Pedicels and internodes not grooved with a translucent median line

	a	Pedicelled spikelets all awnless	Sorghum
	b	Pedicelled spikelets usually reduced to pedicels, sometimes some pedicels bear awned spikelets similar to sessile ones on same inflorescence	Sorghastrum

	a	Lower floret male or sterile, upper bisexual
	b	Both florets bisexual or upper male, sterile or reduced

	a	Lower floret with stout, geniculate awn from lower third of lemma	*Arrhenatherum
	b	Lower floret awnless or, if awned, awn not geniculate

	a	Upper glume gibbous
	b	Upper glume not gibbous

	a	Glumes very unequal in size, distinctly ribbed, upper glume without rigid hairs developing after fertilisation Spikelet 2.5-3.5 mm long	Sacciolepis
	b	Glumes ± equal in size, not distinctly ribbed, upper glume with rigid hairs developing after fertilisation Spikelet 3.5-5.0 mm long	Pseudechinolaena

	a	Upper lemma awned
	b	Upper lemma awnless or mucronate

	a	Spikelets solitary Glumes similar Spikelet light brown to black	Cleistachne
	b	Spikelets paired Glumes very dissimilar Spikelet pale-coloured

	a	Spikelets unequally pedicellate Lower glume flattened on back Inflorescence a panicle Plants robust, tufted	Miscanthus
	b	Spikelets: one sessile and the other pedicelled Lower glume with broad median groove Inflorescence of spike-like racemes along central axis Plants delicate, usually rambling or creeping	Microstegium

	a	Spikelet surrounded by an involucre of long, spreading hairs from callus	Miscanthus
	b	Spikelet not obviously surrounded by involucre of long, spreading hairs from callus or callus glabrous or absent

	a	Lower glume conspicuously awned	Oplismenus
	b	Lower glume awnless or minutely awned

	a	Lemma margins lying flat and enclosing palea
	b	Lemma margins inrolled and clasping palea edges

	a	Lower glume up to a quarter of length of spikelet	Digitaria
	b	Lower glume two-thirds of length of spikelet	Tarigidia

	a	Inflorescence a panicle, open or condensed	Panicum
	b	Inflorescence of spike-like racemes scattered along the central axis

	a	Lower glume adaxial (adjacent to rachis, sometimes difficult to see) Lower glume well developed	Brachiaria
	b	Lower glume abaxial (turned away from rachis), sometimes lower glume absent but spikelet still turned in this position Lower glume absent or scale-like, rarely up to half as long as spikelet	Paspalum

	a	Lemmas all awnless
	b	Lemmas all, or at least one in spikelet, awned or mucronate

	a	Spikelet large, 7-45 mm long Ovary pilose Glumes as long as to longer than spikelet	*Avena
	b	Spikelet small, up to 8 mm long Ovary glabrous Glumes shorter than to rarely ± as long as spikelet

	a	Lemma distinctly keeled on back, at least near base
	b	Lemma rounded on back, at least at base (sometimes keeled on all nerves)

	a	Spikelet 3.0-6.0 mm long Lemma 5-7(11)-nerved	Poa
	b	Spikelet 1.0-3.5 mm long Lemma 3-nerved

	a	Inflorescence a panicle, dense, divaricately branched Stamens 2	Diandrochloa
	b	Inflorescence of spike-like racemes scattered along central axis Stamens 3	Leptochloa

	a	Glumes ± equal in size
	b	Glumes unequal in size

	a	Glumes shorter than spikelet Internodes elongated between florets	*Periballia
	b	Glumes ± as long as spikelet Internodes not elongated between florets	*Aira

	a	Annuals Lower glume minute, scale-like to almost absent, 0-nerved Spikelet 2-3 mm long	*Sphenopus
	b	Perennials Lower glume well developed, 1-3-nerved Spikelet 3-20 mm long

	a	Lemma 1-3 mm long, tips scarious, obtuse or blunt, often ragged	Puccinellia
	b	Lemma 3.5-11.0 mm long, tips firm, acute	Festuca

	a	Lemma awn with ring of hairs at junction of twisted column and clavate limb	*Corynephorus
	b	Lemma mucronate or awned, awn without a ring of hairs or clavate limb

	a	Lower lemma awnless Upper lemma with short hooked awn from back near apex Spikelets falling with glumes	Holcus
	b	Lemmas all similar, all awned or mucronate (upper lemmas may be reduced) Spikelets disarticulating above glumes

	a	Annuals
	b	Perennials

	a	Spikelet 18-46 mm long	*Avena
	b	Spikelet 1.9-14.0 mm long

	a	Glumes shorter than spikelet
	b	Glumes as long as to longer than spikelet

	a	Lemma minutely awned or mucronate Upper glume keeled	Leptochloa
	b	Lemma awn long and obvious Upper glume rounded on back	*Vulpia

	a	Lemma awn geniculate or at least slightly bent	*Aira
	b	Lemma mucronate or awned, awn straight

	a	Lemma with long, obvious hairs on margins Glume tips straight Lemma with fine bristle-like awn, rounded on back	Trichoneura
	b	Lemma pilose around lower half of midrib, or glabrous Glumes with caudate curving tips Lemma mucronate, keeled	Dinebra

	a	Awn of lemma, at least of lower lemma, much longer than body of lemma
	b	Awn of lemma shorter than, to equal to body of lemma, rarely slightly longer than lemma or mucronate

	a	Awn of lemma very long and flexuous, intertwining with awns from other florets, resulting in spikelet falling as a unit	Streblochaete
	b	Awn of lemma stiff, not flexuous and intertwining with awns of other florets for spikelet to fall as a unit

	a	Spikelet 3-6 mm long Ovary glabrous	*Deschampsia
	b	Spikelet 7-30 mm long Ovary hairy

	a	Lower lemma with central awn from upper third of back Lemma awns all similar	Helictotrichon
	b	Lower lemma with central awn from lower third of back Lemma awns differ in same spikelet	*Arrhenatherum

	a	Glumes unequal in size
	b	Glumes ± equal in size

	a	Spikelet 5-20 mm long
	b	Spikelet 2-4 mm long

	a	Lemma rounded on back, at least near base Inflorescence not lobed, spikelets not in dense one-sided clusters	Festuca
	b	Lemma strongly keeled Inflorescence lobed with dense clusters of spikelets crowded on one side at ends of branches	*Dactylis

	a	Inflorescence a dense, contracted panicle Spikelet 3.5-4.0 mm long Palea membranous projecting out of mature florets Lemma entire	Koeleria
	b	Inflorescence open, of numerous racemes scattered along elongated central axis Lemma 2-lobed	Leptochloa

	a	Inflorescence lobed, dense clusters of spikelets crowded on one side at ends of branches	*Dactylis
	b	Inflorescence open or contracted, not lobed

	a	Inflorescence of racemes scattered along central axis Spikelet 5.5-9.0 mm long	Bewsia
	b	Inflorescence a panicle Spikelet 3-6 mm long

	a	Inflorescence open Lemma awned from near base, rounded on back	*Deschampsia
	b	Inflorescence contracted Lemma awned or mucronate from apex or just below, keeled	Koeleria

	a	Florets 3, lower 2 sterile or male (often reduced to lemma only), upper floret bisexual
	b	Florets 3 or more, if 3 then lower floret bisexual and uppermost sterile or reduced

	a	Glumes reduced to minute lips, separated from florets by a stipe	*Microlaena
	b	Glumes conventional, lower sometimes shorter than upper or reduced, not separated from florets by a stipe

	a	pper glume 5-nerved Lower two lemmas usually similar, awnless or tapering into awns, (sometimes only one awned)	Ehrharta
	b	Upper glume 3-nerved First lemma awned from above middle of back, awn usually straight Second lemma awned from near base, awn often robust, twisted in lower part	Anthoxanthum

	a	Lemma as broad as long, gibbous and cordate at base Lemma 7-9-nerved	*Briza
	b	Characters not in same combination as for Briza

	a	Lemma awnless
	b	Lemma awned or mucronate (sometimes minutely so)

	a	Spikelet 1.0-3.5 mm long
	b	Spikelet 4-90 mm long

	a	Lemma 5-many-nerved Upper glume usually 3-nerved
	b	Lemma 3-nerved Upper glume 1-nerved, 1-3-nerved in Koeleria

	a	Glumes ± equal in size, rarely unequal, keeled	Poa
	b	Glumes very unequal in size, not keeled	Puccinellia

	a	Inflorescence of racemes scattered along central axis	Leptochloa
	b	Inflorescence an open or contracted panicle

	a	Lemma rounded but keeled on 3 nerves Lower glume 0-nerved	*Sphenopus
	b	Lemma strongly keeled Lower glume usually 1-nerved

	a	Annuals Spikelet 1-3 mm long Lemma 0.5-1.0 mm long	Diandrochloa
	b	Perennials Spikelet 3.5-4.0 mm long Lemma 3-5 mm long	Koeleria

	a	Lemma distinctly and strongly keeled
	b	Lemma rounded on back, at least at base or keelless

	a	Palea thinner in texture than lemma Lemma 3-nerved Glumes as long as to longer than spikelet	Koeleria
	b	Palea similar in texture to lemma Lemma 5-many-nerved Glumes shorter than spikelet	Poa

	a	Upper glume 1-nerved
	b	Upper glume 3-11-nerved

	a	Spikelet laterally compressed Lemma acute and entire	Festuca
	b	Spikelet ± terete or dorsivenrally to not noticeably compressed Lemma ± truncate or 2-lobed	Leptochloa

	a	Glumes unequal in size
	b	Glumes ± equal in size

	a	Upper florets reduced to lemmas, these form a terminal club-shaped appendage Lower lemmas with long silky hairs	Melica
	b	Upper florets, if reduced, not forming a clavate appendage Lower lemmas glabrous or short-hairy

	a	Spikelet 6-20 mm long Lemma tips firm, acute	Festuca
	b	Spikelet 3.0-5.5 mm long Lemma tips scarious, blunt, often somewhat ragged	Puccinellia

	a	Glumes much shorter than spikelet Spikelet 5-7(-10) mm long Annuals	Catapodium
	b	Glumes equal to or longer than spikelet Spikelet 5-46 mm long Annuals or perennials

	a	Spikelet 5-15 mm long Upper florets reduced to lemmas, these forming a club-shaped appendage Perennials	Melica
	b	Spikelet 17-46 mm long Upper florets sometimes reduced but not forming a club-shaped appendage Annuals	*Avena

	a	Lemma with flexuous awn up to 3 times longer than body of lemma, all awns of a spikelet twisting together and spikelet falling as a unit	Streblochaete
	b	Lemma awn short or long, not intertwining with other awns in spikelet and spikelet falling as a unit

	a	Lemma awned, awn geniculate
	b	Lemma mucronate or awned, awn straight

	a	Glumes as long as to longer than spikelet Annuals Lemma similar in texture to glumes	*Avena
	b	Glumes shorter than spikelet (except in H. galpinii) Perennials Lemma firmer in texture than glumes	Helictotrichon

	a	Inflorescence lobed Spikelets in dense, shortly pedicelled, secund clusters at ends of short branches	*Dactylis
	b	Inflorescence not lobed Spikelets not in clusters at ends of short branches

	a	Upper glume 1-nerved
	b	Upper glume 2-11-nerved

	a	Lemma awn more than half as long as body of lemma
	b	Lemma mucronate or awn less than half as long as body of lemma

	a	Spikelet 6-20 mm long Annuals Glumes rounded on back	*Vulpia
	b	Spikelet 1-3 mm long Perennials Glumes keeled	Chloris

	a	Glumes slightly shorter to much longer than spikelet
	b	Glumes much shorter than spikelet

	a	Inflorescence a dense contracted panicle	Koeleria
	b	Inflorescence of spike-like racemes scattered along central axis

	a	Lemma with central awn terminal, arising from sinus at apex	Trichoneura
	b	Lemma with central awn from back below apex	Bewsia

	a	Inflorescence of racemes scattered along central axis
	b	Inflorescence an open or contracted panicle

	a	Lemma awned from back, below apex	Bewsia
	b	Lemma mucronate or awned, from apex

	a	Spikelets 1.9-3.2 mm long, laterally compressed Lemma keeled	Leptochloa
	b	Spikelet 7-14 mm long, ± terete Lemma ± rounded on back	(=Diplachne) Leptochloa

	a	Spikelet 6-20 mm long Glumes usually much shorter than adjacent lemmas Lemma rounded on back, at least at base	Festuca
	b	Spikelet 3.5-4.0 mm long Glumes as long as (at least lower) to slightly shorter than adjacent lemmas Lemma keeled	Koeleria

	a	Glumes as long as to longer than spikelet or slightly shorter
	b	Glumes shorter than spikelet (except in Helictotrichon galpinii)

	a	Spikelet 3-4 mm long Lemma mucronate or awned, awn minute	Koeleria
	b	Spikelet 17-46 mm long Lemma awn conspicuous, much longer than body of lemma	*Avena

	a	Lower glume 5-9-nerved Ovary with a conspicuous villous appendage at apex
	b	Lower glume 0-3-nerved Ovary glabrous or hairy, without villous appendage at apex except in Bromus

	a	Inflorescence usually an open to contracted panicle	Bromus
	b	Inflorescence usually of racemes scattered up central axis	Brachypodium

	a	Ovary with a conspicuous, villous appendage at apex	Bromus
	b	Ovary hairy or glabrous, without villous appendage at apex

	a	Awn as long as or longer than body of lemma
	b	Awn shorter than body of lemma or mucronate

	a	Annuals Lemma entire, apex tapering into an awn	*Vulpia
	b	Perennials Lemma lobed, awn from upper part of back	Helictotrichon

	a	Lemma awned from upper part of back	Helictotrichon
	b	Lemma mucronate or awned from apex or sinus

	a	Lemma rounded on back, at least near base	Festuca
	b	Lemma keeled

	a	Inflorescence of racemes along central axis, these usually forming a compact cluster	Eleusine
	b	Inflorescence an open or contracted panicle	Poa

	a	All or most spikelets in inflorescence subtended by 1 or more bristles (these may not be obvious)
	b	Spikelet not subtended by bristles

	a	Bristle(s) not falling with spikelet	Setaria
	b	Bristle(s) falling with spikelet	Pennisetum

	a	Floret 1 per spikelet
	b	Florets 2-many per spikelet

	a	Spikelet up to 6 mm long, awnless
	b	Spikelet up to 30 mm long, awned or mucronate (either may be minute), sometimes lemma awnless but then apex awn-like and spikelet 8-15 mm long

	a	Lemma glabrous
	b	Lemma hairy

	a	Lemma similar in texture to glumes Upper glume not to slightly 1-keeled Inflorescence a panicle	Sporobolus
	b	Lemma less firm in texture than glumes Upper glume flat on back, infolded with 2 keels Inflorescences spike-like racemes scattered up central axis	Craspedorhachis

	a	Lemma 5-7-nerved Glumes similar in form	Pentaschistis
	b	Lemma 3-nerved Glumes very dissimilar in form

	a	Inflorescence open with racemes scattered up along central axis Glumes ± equal Lemma less firm in texture than glumes	Craspedorhachis
	b	Inflorescence dense and racemes appressed to central axis Glumes very unequal Lemma similar in texture to glumes	Polevansia

	a	Ligule a fringed membrane
	b	Ligule a fringe of hairs

	a	Glumes similar in form Spikelet terete to laterally compressed Lemma awn long, geniculate	Stipa
	b	Glumes dissimilar in form Spikelet dorsiventrally compressed, lemma with short mucro

	a	Inflorescence open with racemes scattered up along central axis Glumes ± equal Lemma less firm in texture than glumes	Craspedorhachis
	b	Inflorescence dense and racemes appressed to central axis Glumes very unequal Lemma similar in texture to glumes	Polevansia

	a	Lemma mucronate or minutely awned or awnless and sometimes awn-like
	b	Lemma 3-awned (due to fusion it may appear as a single awn with 3 branches)

	a	Spikelet 10-18 mm long Lemma incised Inflorescence large, plumose with many spikelets Large tussock-forming plant up to 4 m tall Lemma awn-like, long drawn-out to a filiform tip	*Cortaderia
	b	Spikelet 2-5 mm long Lemma entire Inflorescence of racemes scattered along central axis Small plant up to 1.2 m tall

	a	Glumes very unequal in size Upper glume rounded on back, keelless	Willkommia
	b	Glumes ± equal in size Upper glume flat-backed, 2-keeled	Craspedorhachis

	a	Lemma hairy, distinctly 2-lobed, lobes awned, central awn present	Pentameris
	b	Lemma glabrous, not appearing lobed, 3 awns from apex of lemma or seemingly from top of column

	a	Awns of lemma all or only central one plumose (S. anomala with awn solitary and with a pencil of hairs at base of column) Palea indurated	Stipagrostis
	b	Awns of lemma all glabrous, smooth or scabrid, (lateral awns may be reduced or absent) Palea not indurated

	a	Upper glume 3-5-nerved Lower glume usually 3-nerved Glumes rounded to flat on back, more than 1-keeled Awns spirally contorted at base Caryopsis with a deep ventral groove	Sartidia
	b	Upper glume 1(3)-nerved Lower glume nearly always 1-nerved Glumes 1-keeled to middle or below Awns not spirally contorted at base Caryopsis not deeply grooved	Aristida

	a	Spikelets in triads Pedicels entirely or partly fused mimicking a single spikelet Spikelet long-awned 2 florets per spikelet	Tristachya
	b	Spikelets solitary, paired, clustered or in triads but then pedicels free Spikelet awned or awnless, with 2-many florets

	a	Florets 2 per spikelet
	b	Florets 3-many per spikelet

	a	Upper lemma of bisexual spikelet less firm in texture than glumes Spikelets usually paired, one sessile and the other pedicellate and dissimilar in form and function, or in triads, rarely paired or solitary and similar in form and function
	b	Lemma of bisexual floret similar to firmer in texture than glumes Spikelets solitary, in pairs, triads or groups, similar in form and function

	a	Spikelets solitary or in pairs, equally or unequally pedicelled, or sessile Spikelets of pairs similar in form and sexuality
	b	Spikelets in pairs, one sessile and the other pedicelled or in triads Spikelets usually dissimilar in form and/or sexuality

	a	Lowest floret male or sterile
	b	Lowest floret bisexual

	a	Glumes very unequal in size Lower lemma resembling upper glume	Melinis
	b	Glumes ± equal in size Lower lemma not resembling upper glume	Miscanthus

	a	Plants reed-like Inflorescence a large plumose panicle	*Arundo
	b	Plants not reed-like Inflorescence not large and plumose

	a	Glumes 1-nerved, awned Lemma 3-nerved, minutely toothed	Dinebra
	b	Glumes 3-7-nerved, awnless Lemma 5-7-nerved, entire	Tribolium

	a	Pedicelled spikelet absent, reduced to a pedicel (occasionally with a spikelet on same inflorescence)	Sorghastrum
	b	Spikelets all present

	a	Spikelets in triads, middle spikelet sessile, two lateral spikelets pedicelled	Chrysopogon
	b	Spikelets usually in pairs, but terminal spikelets often in triads

	a	Pedicels and internodes with a longitudinally grooved translucent line Glumes of sessile spikelet usually with pits	Bothriochloa
	b	Pedicels and internodes without a grooved translucent line Glumes of sessile spikelet without pits

	a	Sessile spikelet compressed laterally Inflorescence of many slender, spike-like racemes in whorls on central axis Lower glume of sessile spikelet spinulose	Vetiveria
	b	Sessile spikelet compressed dorsiventrally Inflorescence an open or dense panicle or of spike-like racemes scattered, not whorled, along central axis and densely appressed to central axis Lower glume of sessile spikelet not spinulose

	a	Inflorescence a large, usually open panicle Sessile spikelet usually long-awned Pedicelled spikelet male or sterile, sometimes reduced to a glume	Sorghum
	b	Inflorescence of spike-like racemes ± appressed up central axis Sessile spikelet awnless Pedicelled spikelet female only	Eriochrysis

	a	Lower floret male or sterile, usually reduced to a lemma Upper floret bisexual
	b	Both florets bisexual or upper sterile

	a	Spikelet supported on a bead-like swelling	Eriochloa
	b	Spikelet not supported on a bead-like swelling

	a	Upper lemma awned or mucronate (either can be minute)
	b	Upper lemma awnless or apiculate

	a	Upper lemma entire
	b	Upper lemma incised (sometimes minutely lobed or emarginate)

	a	Inflorescence a panicle
	b	Inflorescence of spike-like racemes scattered up central axis

	a	Upper glume and lower lemma awned Upper glume awn 3-4 times longer than body of lemma	Oryzidium
	b	Upper glume and lower lemma awnless or, if awned, awn very short	Brachiaria

	a	Lower glume adaxial (adjacent to rachis)
	b	Lower glume abaxial (turned away from rachis) or absent

	a	Upper palea acute with reflexed tip (needs careful dissection) Spikelets usually in 4 or more rows	Echinochloa
	b	Upper palea without reflexed tip Spikelets mostly in 1 or 2 rows	Brachiaria

	a	Lower glume or both glumes long-awned	Oplismenus
	b	Both glumes awnless or with short awn point or only upper glume long-awned

	a	Lower glume absent	Paspalum
	b	Lower glume present (sometimes very small)

	a	Upper lemma shorter than spikelet Upper palea obtuse, its tip not reflexed	Urochloa
	b	Upper lemma ± as long as spikelet Upper palea acute, tip often briefly reflexed	Paspalidium

	a	Ligule a fringed membrane Upper lemma scabrid to scaberulous	Arundinella
	b	Ligule a fringe of hairs Upper lemma usually hairy to glabrous or smooth, rarely scaberulous

	a	Upper lemma glabrous or hairy, hairs not in tufts
	b	Upper lemma hairy, hairs in tufts or tufts mixed with dispersed hairs

	a	Lower lemma 3-nerved	Loudetia
	b	Lower lemma 5-9-nerved

	a	Callus short, oblong, rounded Spikelets ± 10 mm long	Danthoniopsis
	b	Callus long, linear, bifid, pointed or pungent Spikelet 10-35 mm long

	a	Longest pedicel of spikelet group just over twice as long as shortest pedicel, pedicels stout	Loudetia
	b	Longest pedicel of spikelet group much longer than shortest pedicel, not stout	Tristachya

	a	Upper lemma with 2 tufts of hairs Upper palea keels wingless Stamens 2 Leaves deflexed	Trichopteryx
	b	Upper lemma with 6-8 tufts of hair, sometimes tufts mixed with dispersed hairs Upper palea keels winged Stamens 3 Leaves not reflexed	Danthoniopsis

	a	Upper lemma hairy	Entolasia
	b	Upper lemma glabrous

	a	Upper lemma with distinct green crest at apex	Acroceras
	b	Upper lemma not crested at apex, sometimes beaked

	a	Lower lemma with 2 transverse fringes of long hairs on back Upper glume tapering to an awn-like apex, with 2 tufts or a continuous transverse fringe of long hairs just above middle	Leucophrys
	b	Lower lemma and upper glume glabrous, hispidulous or hairy, hairs not in transverse fringes of long hairs on back above middle, tufts of short hairs sometimes present

	a	Inflorescence an open or condensed panicle
	b	Inflorescence of one-sided racemes scattered up central axis, sometimes with secondary branches

	a	Upper lemma coriaceous to crustaceous Lower lemma entire
	b	Upper lemma cartilaginous Lower lemma emarginate or lobed

	a	Spikelet laterally compressed Upper glume gibbous or saccate at base, prominently ribbed	Sacciolepis
	b	Spikelet ± dorsally compressed Upper glume usually not gibbous nor prominently ribbed	Panicum

	a	Upper floret laterally compressed Spikelet awned or awnless	Melinis
	b	Upper floret dorsally compressed Spikelet awnless or minutely mucronate	Tricholaena

	a	Spikelet hispidulous Upper palea acute, tip reflexed, slightly protuberant (needs careful dissection)	Echinochloa
	b	Spikelet hairy or glabrous Upper palea obtuse or acute but then tip not reflexed

	a	Lower glume awned	Oplismenus
	b	Lower glume awnless or glume absent

	a	Spikelet abaxial (lower glume turned away from rachis) Lower glume usually absent, rarely up to half as long as spikelet	Paspalum
	b	Spikelet adaxial (lower glume turned towards rachis) Lower glume present	Brachiaria

	a	Spikelet awnless, 1.5-8.0 mm long (sometimes so long-acuminate as to appear awned)
	b	Spikelet awned or mucronate, if awnless then 10-18 mm long (lemma sometimes awn-like)

	a	Glumes with long, glassy hairs Lemma with fringe of hairs on margins	Tribolium
	b	Glumes glabrous or hairy, hairs not long and glassy Lemmas glabrous or hairy, hairs not in fringes on margins

	a	Spikelet up to 2.5 mm long	Eragrostis
	b	Spikelet 3-7 mm long

	a	Spikelet dorsiventrally compressed	Leptochloa
	b	Spikelet laterally compressed

	a	Glumes ± as long as to much longer than spikelet Lemma 2-lobed, dorsally rounded	Pentaschistis
	b	Glumes much shorter than spikelet Lemma entire, keeled

	a	Inflorescence a panicle Upper glumes usually 3-nerved Lemma 5-7(-11)-nerved	Poa
	b	Inflorescence of spike-like racemes scattered up central axis (often resembling a herring-bone) Upper glume 1-nerved Lemma 3-nerved	Pogonarthria

	a	Lower lemma awnless Upper lemma (sterile floret) awned with short stout hooked dorsal awn	Holcus
	b	Lower lemma or both lemmas awned or mucronate, if upper lemma awned, awn not hooked

	a	Lemma mucronate	Dinebra
	b	Lemma awned (lower lemma sometimes awnless)

	a	Pedicel articulated a distance below spikelet, beaded with long hairs at articulation point, spikelet and part of pedicel falling as a whole Callus hairy, pungent Glumes as long as or longer than spikelet	Chaetobromus
	b	Characters not precisely as for Chaetobromus

	a	Central awn of lemma short and straight, shorter than body of lemma or lemma apex awn-like
	b	Central awn of lemma geniculate, usually longer than body of lemma

	a	Glumes markedly shorter than spikelet
	b	Glumes as long as to longer than spikelet

	a	Lemma incised, 3-lobed at apex, hairy Basal sheaths split, forming a hard fibrous base	Styppeiochloa
	b	Lemma entire, glabrous Basal sheaths not splitting into fibrous base	Pogonarthria

	a	Inflorescence a nonplumose panicle, 170-270 mm long	Merxmuellera
	b	Inflorescence a plumose panicle, 300-800 mm long

	a	Plants reed-like, woody Leaves mainly on culm Plants with all spikelets bisexual Ligule a short, fringed membrane Glumes 3-5 mm long	*Arundo
	b	Plants forming huge tussocks Leaves mainly basal Plants either with all spikelets bisexual or exclusively gynodioecious Ligule a fringe of hairs Glumes 1(-3) mm long	*Cortaderia

	a	Ovary apex hairy Fruit an achene	Pentameris
	b	Ovary apex glabrous Fruit a caryopsis

	a	Glumes 15-60 mm long Lemma firmer in texture than glumes	Pseudopentameris
	b	Glumes 2-12(-20) mm long Lemma similar in texture to glumes

	a	Lemma glabrous, if hairy, then hairs not in tufts (if plant tall and reed-like see Merxmuellera arundinacea)	Pentaschistis
	b	Lemma hairy, hairs in tufts	Merxmuellera

	a	Florets 3 per spikelet, lower 2 sterile, often reduced to lemmas Upper floret bisexual
	b	Florets 3-many per spikelet, all bisexual or upper male, sterile or reduced, or lower 2 and uppermost sterile or reduced, in between florets bisexual, rarely only male or female

	a	Callus present, hairy Glumes reduced to minute lips, separated from florets by a stipe	*Microlaena
	b	Callus absent Glumes of variable length, not reduced to lips, nor separated from florets by a stipe	Ehrharta

	a	Pedicel articulated a distance below spikelet, bearded with long hairs at articulation point, spikelet and part of pedicel falling as a whole Callus pungent, hairy Glumes as long as to longer than spikelet Spikelet 9-18 mm long	Chaetobromus
	b	Characters not precisely as for Chaetobromus

	a	Plants reed-like Leaves mainly cauline
	b	Plants not reed-like

	a	Spikelet awned, awn geniculate or bent and lower part usually twisted	Merxmuellera
	b	Spikelet awned or awnless, awn straight

	a	Glumes very unequal in size, shorter than spikelet Lemma glabrous (but enveloped by long hairs from callus) Mature inflorescence branches flexible, usually drooping	Phragmites
	b	Glumes ± equal in size, as long as spikelet Lemma long-hairy Mature inflorescence branches stiff and ascending	*Arundo

	a	Lemma with an incurved, emarginate apex and a narrow, awned lobe at each margin, sometimes with 1 or 2 shorter, additional lobes, lateral awns long	Kaokochloa
	b	Characters not as for Kaokochloa

	a	Central awn of lemma geniculate or bent, lower part usually twisted
	b	Central awn of lemma short and straight, or lemma shortly mucronate or awnless

	a	Spikelet 4.0-7.0 mm long	Karroochloa
	b	Spikelet 7.5-25.0 mm long

	a	Glumes prominently 7-11-nerved Callus obliquely pungent	Centropodia
	b	Glumes 1-5(-7)-nerved Callus rounded

	a	Glumes 1-keeled to middle or below Palea similar in texture to lemma	Merxmuellera
	b	Glumes rounded, flat or with more than 1 keel Palea thinner in texture than lemma	Dregeochloa

	a	Leaves hard, needle-like Plants prickly
	b	Leaves not needle-like Plants not prickly

	a	Central axis of inflorescence usually ending in a spine, not in spikelets, lateral branches distant as rigid spines or in clusters scattered up central axis	Cladorhaphis
	b	Central axis of inflorescence ending in spikelets, dense and contracted

	a	Glumes very unequal in size, 1-nerved Lemma mucronate or with a short stout awn Long hairs on nerves	Odyssea
	b	Glumes ± equal in size, 5-11-nerved Lemma 3-awned Tufts of hairs on lemma and scattered hairs between nerves	Centropodia

	a	Lemma glabrous
	b	Lemma hairy or long-ciliate

	a	Upper glume 1-nerved
	b	Upper glume 3-7-nerved

	a	Glumes as long as to longer than spikelet	Dinebra
	b	Glumes shorter than spikelet

	a	Inflorescence a large, plumose panicle Lemma apex appears awn-like	*Cortaderia
	b	Inflorescence various, not large and plumose Lemma with true awn or awnless

	a	Upper glume and lemmas with stout awn Spikelets secund, if spikelets not secund see Eragrostis	Acrachne
	b	Upper glume awnless, lemmas awned, mucronate or awnless Spikelets secund or not secund

	a	Inflorescence branches not one-sided Spikelets not secund	Eragrostis
	b	Inflorescence with many spike-like, one-sided racemes spreading from central axis (like a herringbone) Spikelets secund	Pogonarthria

	a	Lemma entire	Eragrostis
	b	Lemma lobed or notched (sometimes minutely so)

	a	Ligule a fringe of hairs Lower glume 5-7-nerved	Schismus
	b	Ligule a fringed membrane Lower glume 1-3-nerved	Brachychloa

	a	Ligule a fringe of hairs
	b	Ligule a fringed membrane

	a	Lemma entire
	b	Lemma incised, emarginate to deeply lobed

	a	Inflorescence large, plumose Lemma with long fine hairs at base reaching ± to apex of body of lemma	*Cortaderia
	b	Inflorescence not large and plumose Lemma without long hairs reaching to apex of body of lemma

	a	Lower glume 5-7-nerved (often best observed in lower part)	Tribolium
	b	Lower glume 1-3-nerved (often best observed in lower part)

	a	Lemma 6-11-nerved Spikelet spiny	Entoplocamia
	b	Lemma 3-5-nerved Spikelet not spiny

	a	Lowest florets bisexual, complete Lemma 3-nerved	Eragrostis
	b	Lowest 2 florets reduced to lemmas Lemma 5-nerved	Tetrachne

	a	Glumes unequal in size
	b	Glumes ± equal in size

	a	Lemma hairs short or stiff, and not obvious or glabrous	Eragrostis
	b	Lemma distinctly hairy, hairs long, usually soft

	a	Plant base hard, dense and fibrous Lemma not deply lobed, with hairs on margin near base, sometimes lateral nerves with short appressed hairs	Styppeiochloa
	b	Plant without fibrous base Lemma deeply lobed, with long hairs from apex to base on lateral nerves	Triraphis

	a	Lemma deeply cleft
	b	Lemma not deeply cleft

	a	Glumes shorter than spikelet Lemma 3-nerved	Triraphis
	b	Glumes as long as to longer than glumes Lemma 7-11-nerved

	a	Callus rounded	Merxmuellera
	b	Callus pungent	Centropodia

	a	Lemma 3-nerved	Eragrostis
	b	Lemma 5-11-nerved

	a	Lemma 1.8-3.0 mm long, not deeply lobed	Schismus
	b	Lemma 5-16 mm long, usually deeply lobed	Merxmuellera

	a	Lemma 3-awned, awns of lobes obvious	Triraphis
	b	Lemma awnless, mucronate or 1-awned, entire or lobed, awns on lobes minute

	a	Lowest lemma awned, central awn more than twice as long as body of lemma	Chloris
	b	Lowest lemma awnless, mucronate or awned, awn less than twice as long as body of lemma

	a	Upper glume 1-nerved
	b	Upper glume 3-7-nerved (often clearer on inner surface)

	a	Lemma saccate at base, hairs club-shaped Spikelet laterally compressed Palea shorter than lemma	Coelachyrum
	b	Lemma not saccate at base, hairs acute Spikelet dorsiventrally compressed (± terete) Palea ± equal to lemma	Leptochloa

	a	Lemma 3-nerved	Brachychloa
	b	Lemma 5-9-nerved	Tribolium