Spikelets concealed in burrs
Spikelets not concealed in burrs
Inflorescence of a group of 1-4 spikelets enclosed within the upper leaf sheaths; only styles and anthers exposed (kikuyu)
Inflorescence not enclosed within the leaf sheaths or, if partly so then of more than 4 spikelets
Separate male and female or bisexual plants
Plants all having bisexual spikelets (except Distichlis which is a low-growing plant with distichous leaves)
Rhachis of the inflorescence branches continued beyond the spikelets as a prominent bristle; coastal dune plants
Rhachis of the inflorescence branches not continued as a conspicuous bristle; arid area plants
Large reeds or bamboos 2 m or more high
Smaller grasses usually under 1.5 m high
True bamboos; culms woody and with many branches from each node
Reeds, largely or entirely branched from at or near the base
Glumes 3-5-veined
Glumes 1-veined
Lemmas 5-9-veined, silky-hairy
Lemmas 1-veined, not hairy (hairs elsewhere may make this difficult to see)
Inflorescence of 2 or more racemes or spikes arising from or appearing to arise from the apex of the culm
Inflorescence a single raceme, spike or panicle or a single spikelet
Spikelets with 1 or more awns
Spikelets with no awns
Spikelets arranged in pairs or threes
Spikelets arranged singly
One spikelet awned, one spikelet awnless
Both spikelets awned
Lemma awn up to 1 mm long
Lemma awn 3 mm or more long
Racemes 0.5-4 cm long
Racemes 7-17 cm long
Fertile lemma with conspicuous membranous wings
Fertile lemma not conspicuously winged
Lemma laterally compressed
Lemma dorsally compressed
Bisexual floret single; lemmas 1 or 2
Bisexual florets 2-7; lemmas 3 or more
Spikelets with one bisexual lemma only
Spikelets with one bisexual floret and one sterile floret below it
Glumes longer than the lemma; lemma with a ring of hairs below the apex (sometimes difficult to see)
Glumes shorter than the lemma; lemma glabrous except along the keel
Lemma margins relatively thin and lying flat on the palea
Lemma margins relatively thick and the very edges turned in
Lemmas 3-4.5 mm long
Lemmas 1.5-2 mm long
Inflorescence a raceme, spike (make sure that there are no short branches with a few spikelets and therefore a panicle) or a single spikelet
Inflorescence a panicle (sometimes with short branches with a few spikelets and therefore looking spike-like)
Spikelets (at least the fertile ones) with 1 or more awns
Spikelets (at least the fertile ones) with no awns
Lemmas 1 or 2 in each spikelet
Lemmas 3 or more in each spikelet
Spikelets with 1 lemma
Spikelets with 2 lemmas (not necessarily both fertile)
Spikelets reflexed
Spikelets not reflexed (usually more or less erect)
Glumes awned; lemma awnless
Glumes awnless; lemma awned
Awn rising obviously from the back of the lemma
Awn terminal, sometimes from within a sinus in the apex of the lemma
Lemma tightly curled to form an apparently solid structure; awn terminal
Lemma an obviously flat structure; awn from within a sinus in the apex of the lemma
Lemma with short erect hairs at the apex and/or with short hairs on the body of the lemma
Lemma with a conspicuous spreading whorl of long hairs towards the apex
Lemma 3-awned
Lemma and glumes each with 0 or 1 awn
Lemma with an awn arising in a sinus in the apex of the lemma; sterile spikelets with many awnless lemmas also present
Lemma and glumes unawned or tapering into an awn; sterile spikelets absent
Lemmas conspicuously awned; glumes with an inconspicuous awn or awnless
Lemmas not awned; glumes awned
Leaf auricles absent or inconspicuous; glume awns shorter than the body of the glumes or 0
Leaf auricles well developed; glume awns at least as long as the body of the glumes
Glumes glabrous; glume awn often hooked at the apex
Glumes hairy, often especially along the margins; glume awn not hooked
Lemma awn distinctly arising on the back of the lemma
Lemma tapering into the awn or the awn arising between teeth or lobes
Lemma apex entire, often tapering into the awn
Lemma apex deeply or shallowly lobed, notched or toothed
Spikelets pedicellate, sometimes shortly so
Spikelets sessile
Lemmas all similar (possibly decreasing slightly in size towards the apex)
The lowest 2 lemmas sterile and distinctly different from the fertile one
A tufted annual
A spreading rhizomatous perennial
Fertile lemma awnless; glumes usually more than 2 mm long, enclosing the base of the lemmas
Fertile lemma shortly awned; glumes to 2 mm long, separated from the lemmas
Spikelets arising on all sides of the rhachis forming a cylindrical spike
Spikelets in 2 opposite rows on the rhachis forming a flattened spike
Perennial; leaf auricles absent
Annual; leaf auricles present
Spikelets with their single glume away from the rhachis (terminal spikelet with 2 glumes)
Spikelets with their sides against the rhachis; glumes 2
Tufted plants without rhizomes but sometimes stoloniferous
Tufted plants with extensive rhizomes
Spikelets sessile or subsessile
Spikelets distinctly pedicellate
Lateral lobes drawn out into a point, sometimes awned
Lateral lobes short and rounded
Spikelets side on to the rhachis
Spikelets with one glume towards and one away from the rhachis
Lower sheaths woolly around the more or less swollen base of the plant
Lower sheaths not woolly
Lemma 1-awned
Lemmas distinctly 3-awned
Callus more than twice the length of the internode of the spikelet axis
Callus up to twice the length of the internode of the spikelet axis
Lemma single
Lemmas 2 or more
Glume single
Glumes 2
Spikelets 4.5-7 mm long
Spikelets 2.3-3.5 mm long
Separate male and female plants; leaves strongly distichous
All plants with bisexual spikelets; leaves usually basal or spreading from all sides of the culm
Spikelets all distinctly pedicellate (the pedicels at least one-quarter of the length of the spikelet)
Spikelets sessile or almost so
Spikelets with 1 bisexual floret
Spikelets with 2 or more bisexual florets
1 sterile lemma below the fertile one
2 sterile lemmas below the fertile one
2nd lemma conspicuously corrugated
Lemmas not corrugated
Leaf sheaths fused to form a cylinder
Leaf sheaths margins overlapping but free of one another to their bases
Lemmas entire; glumes conspicuously cordate
Lemmas 2- or 3-lobed (sometimes shallowly so) at the apex; glumes not cordate
Leaf blades soft, flat
Leaf blades firm, tightly rolled and pungent
Spikelets side on to the rhachis
Spikelets with one glume towards and one away from the rhachis
Tufted annual; glumes more or less keeled
Rhizomatous perennials; glumes rounded on their backs
Rhachis never disarticulating, scabrid
Rhachis disarticulating below the spikelets (sometimes at a late stage), glabrous
Spikelets with 1 bisexual floret
Spikelets with 2 or more bisexual florets
Spikelets articulated above the glumes
Spikelets articulated below the glumes
Inflorescence a compact spike
Inflorescence a raceme
First glume with a hyaline window in the lower part
First glume variously thickened but without a hyaline window
Glumes similar to one another; second lemma entirely membranous or hyaline
First glume thin, second hardened and inconspicuously veined below; second lemma cartilaginous below
Spike subtended by a leaf that exceeds it in length
Spike not subtended by a leaf
Spikelets (except the terminal one) with a single glume
Spikelets all with 2 glumes
Spikelets paired at each node
Spikelets single at each node
Spikelets (at least the fertile ones) with 1 or more awns
Spikelets (at least the fertile ones) with no awns
Lemma single in each spikelet
Lemmas 2 or more in each spikelet
Awn 3-branched, with or without a common column below the branches
Awns simple, although sometimes more than 1 from each lemma
Lemma 3-5-lobed or toothed, awned
Lemma entire or 2-lobed, often awnless
Lemma 5-lobed or toothed
Lemma 3-lobed
Lemma apex toothed
Lemma 5-lobed
All 3 lobes ending in awns
Only the central awn with an awn
Articulation of the spikelets below the glumes
Articulation of the spikelets above the glumes
Glumes awnless, 3-veined
Glumes awned, 1- or 3-veined
Glumes 3-veined
Glumes 1-veined
Glumes and lemmas both awned
Glumes not awned
Glumes and their awns shortly hairy or scabrid
Glumes and their awns long-hairy
Lemma with a straight or somewhat bent but not twisted awn
Lemma with a bent and twisted awn
Awn dorsal
Awn terminal or subterminal
Spikelets in groups of 3
Spikelets arising singly along the rhachis
Leaf blades tightly rolled and rigid
Leaf blades flat or loosely rolled
Glumes 4.5-9 mm long
Glumes 2-4 mm long
Lemma awn apparently terminal from the tightly rolled lemma
Lemma awn dorsal, although sometimes from close to the apex of the more loosely rolled lemma
Lemma with a conspicuous whorl of long spreading hairs towards the apex
Lemma with short erect hairs at the apex and/or with short hairs on the body of the lemma
Hairs at apex of lemma absent or free
Hairs at apex of lemma fused to form a corona
Awn arising at or near the apex of the lemma
Awn arising near or below the middle of the lemma
Lemma broad, often truncate, membranous
Lemma narrower, more or less acute, hardened
Bisexual floret single in each spikelet
Bisexual florets 2 or more in each spikelet
Inflorescence comprising both bisexual and male or sterile spikelets
Inflorescence of bisexual spikelets only
Spikelets arranged singly along the rhachis; 1st lemma of bisexual spikelets bisexual
Spikelets in groups of 2 or 3 along and/or terminating the rhachis; 1st lemma of bisexual spikelets sterile or male
Spikelets in threes (1 bisexual and 2 male or sterile) surrounded by 4 more male or sterile spikelets
Spikelets in pairs or threes (1 bisexual and 1 or 2 male or sterile) without further sterile spikelets surrounding them
Culms usually less than 50 cm high; all spikelets falling together
Culms usually more than 50 cm high; the whorl of 4 male or sterile spikelets remaining on the plant when the group of three including the spikelet is shed
Racemes in pairs at the end of short branches, with a spathe or a long sheathing bract permanently supporting each pair
Racemes not in pairs supported by a common spathe
Awn glabrous
Awn hairy especially on the lower part
Spikelets in threes at the ends of slender branches
Spikelets predominantly in pairs along the branches
Glumes of bisexual spikelets 2-keeled, often pitted
Glumes of bisexual spikelets not keeled or pitted
Sterile or male lemmas 1 or more, above the bisexual floret(s)
Sterile or male lemmas below the bisexual floret
Lemma with about 9 stiff plumose awns
Lemma with 1 slender awn
Two sterile or male lemmas below the single bisexual lemma
One sterile or male lemma below the single bisexual lemma
Inflorescence a dense spike-like panicle; plant sweetly scented
Inflorescence an open panicle; plant not scented
Fertile lemma awnless; glumes enclosing the base of the lemmas
Fertile lemma shortly awned; glumes to 2 mm long and separated from the lemmas
2nd glume awned
Glumes awnless
1st lemma with a geniculate awn from below the middle of its back
Awns terminal or subterminal
Spikelets in pairs; awns with a twisted column
Spikelets single at each node; awns more or less straight and not twisted
2nd glume towards the rhachis
2nd glume away from the rhachis
1st glume vestigial or 0
1st glume often small but always clearly visible
Spikelets articulated above the glumes
Spikelets articulated below the glumes
Awn terminating the 2nd lemma
Glumes tapering into awns; lemmas awnless
Bisexual florets 2 in each spikelet
Bisexual florets 3 or more in each spikelet
Awn dorsal
Awn terminal or subterminal
Glumes more than 15 mm long
Glumes less than 10 mm long
Annuals; lemmas without an extension of the rhachilla
Perennials; lemmas with an extension of the rhachilla
Lemmas with about 9 terminal plumose awns
Lemmas with a single glabrous, scabrid or shortly hairy awn
Fertile spikelets accompanied by conspicuous sterile spikelets
Spikelets all similar and fertile
Glumes 7-11-veined
Glumes 1-3-veined
Lemmas with a single awn
Lemmas with a terminal and 2 lateral awns
Lemma apex entire
Lemma apex 2- or 3-lobed or notched (sometimes very shallowly so)
Spikelets sessile in a terminal spike-like panicle composed of globular clusters of spikelets
Spikelets in a loose panicle or, if the panicle is spike-like, spikelets pedicellate
Lemmas rounded on the back at least in the lower part
Lemmas keeled on the back by a prominent midrib
Annuals; awn longer than the lemma
Perennials; awn usually shorter than the lemma
Lemma acute; glumes keeled
Lemma obtuse; glumes rounded on their backs or with a prominent midrib
2nd glume 1-veined
2nd glume 3-9-veined
Separate male and female plants; rhizomatous perennials; leaves in 2 rows
Plants all bisexual; rhizomes absent, annuals or perennials; leaves basal or arising from all sides of the culm
Annual; lemmas at least 6 mm long; 1st glume shorter than the 2nd
Perennial; lemmas 2-5 mm long; glumes subequal in length
Lemma with a dorsal awn
Lemma midrib extending through the apex into the awn
Glumes enclosing the lemmas
Glumes shorter than the lemmas
Leaf sheaths fused to form a cylinder
Leaf sheaths margins overlapping but free of one another to their bases
Fertile spikelets accompanied by conspicuous sterile spikelets
Spikelets all similar and fertile
Lemmas each with 3 awns
Lemmas each with 1 awn
Leaves tightly rolled, rigid, pungent
Leaves flat or loosely rolled, relatively soft
Central awn arising from a long central lobe of the lemma
Central awn arising from the sinus between the 2 lobes of the lemma
Callus more than twice the length of the internode of the spikelet axis
Callus up to twice the length of the internode of the spikelet axis
Upper row of lemma hair tufts absent
Upper row of lemma hair tufts present
Awn strongly bent and twisted; basal of plant woolly
Awn straight or slightly bent; base of plant not woolly
Leaves tightly rolled, rigid, pungent
Leaves flat or loosely rolled, relatively soft
1st glume less than half as long as the 2nd glume
1st glume more than half as long as the 2nd glume
Awn to 1 mm long; 2nd glume usually much shorter than the 1ast lemma
Awn 1-5.5 mm long; 2nd glume nearly as long as the 1st lemma
Lemma single in each spikelet
Lemmas 2 or more in each spikelet (see Paspalum in which the total loss of 1 glume may lead to the first lemma being mistaken for the second glume)
Spikelets furnished with hooked spines
Spikelets without spines
Articulations above the glumes
Articulation below the glumes
1st glume distinctly shorter than the lemma
1st glume about as long as or longer than the lemma
Panicle spike-like; leaves tightly rolled and rigid
Panicle more or less open; leaves flat or loosely rolled and moderately soft
Rhachilla not extended beyond the lemma or less than one-fifth of the lemma length; inflorescence remaining attached to the plant
Rhachilla usually at least one-third of the length of the lemma; inflorescence usually separating from the plant at maturity of the fruits
Glumes 1-3.5 mm long; inflorescence a more or less dense spike-like panicle
Glumes 8-18 mm long; inflorescence a number of spike-like racemes
Bisexual floret 1 per spikelet
Bisexual florets 2 or more per spikelet
Stiff and often scabrid or hairy bristles on the inflorescence axis below some or all spikelets or with a bristle terminating the rhachis
Bristles not present, but often the inflorescence axes softly or shortly hairy
At least 1 bristle at the base of every spikelet
Bristles along each rhachis (not directly associated with individual spikelets), at the base of the terminal spikelet, or terminating the rhachis
Bristles persisting on the inflorescence when the spikelets are shed
Bristles falling with the spikelets or the branchlets when these are shed
Panicle branches disarticulating at their bases, falling off with the spikelets
Panicle usually spike-like; bristles shed with each spikelet
A single bristle at the base of the terminal spikelet on each branch or terminating the rhachis
Bristles not restricted to 1 at the base of terminal spikelets
2nd glume truncate; spikelets 8-12 mm long
2nd glume acute; spikelets 2-8 mm long
2nd glume tapering to a long point; spikelets 3-8 mm long
2nd glume more or less acute, not tapering; spikelets 2-4 mm long
Panicle branches disarticulating at their bases, falling off with the spikelets
Panicle branches persisting on the plant
Bristles in the form of coarse hairs along the rhachis of the branches
Bristle terminating the rhachis of the branches
Panicle spike-like
Panicle open or with conspicuous branches
Spikelets sunk in notches in the flat rhachis
Spikelets not sunk in notches in the rhachis
Glumes densely long-hairy
Glumes glabrous, shortly hairy or with localised long hairs
Glumes winged, scabrid or shortly hairy on the keels
Glumes not winged or keeled, long-ciliate on the margins
Glumes similar to one another; second lemma entirely membranous or hyaline
First glume thin, second hardened and inconspicuously veined below; second lemma cartilaginous below
Sterile lemmas 2 or 3
Sterile lemma 1
2nd lemma conspicuously corrugated
Lemmas not corrugated
Sterile lemmas above the bisexual floret
Sterile lemmas below the bisexual floret
Sterile lemma above the bisexual floret
Sterile lemma below the bisexual floret
Glumes subequal in length
1st glume 0 or distinctly smaller than the 2nd glume
Spikelets in pairs; 1 sessile and bisexual, 1 pedicellate and sterile
Spikelets solitary or in groups but all bisexual
1st glume absent or rarely to 2 mm long
Glumes both well developed and usually more than 2 mm long
Spikelets with a disk-like swelling below the glume
Spikelets without a spike-like swelling below the glumes
1st lemma towards the rhachis
1st lemma away from the rhachis
Inflorescence branches not forming well defined spikes or racemes
Inflorescence branches forming well defined spikes or racemes
Spikelets in twos or threes
Spikelets single at each node
1st glume distinctly more than half the length of the spikelet; leaves glabrous
1st glume less than half the length of the spikelet; if about half the length then the leaves more or less hairy
Inflorescence 4-40 cm long; rhachilla short between the glumes
Inflorescence 1.5-3.5 cm long; rhachilla elongated between the glumes
Bisexual lemma with flat translucent margins which are thinner than and pressed against the body of the lemma
Bisexual lemma with narrowly rolled margins of the same texture as the body of the lemma
1st glume towards the rhachis
1st glume away from the rhachis
Lemma 3-lobed or notched or toothed
Lemma apex entire
Leaves rounded in section, rigid and pungent; spikelets 5-30 mm long
Leaves flat or rolled, if slightly pungent the spikelets not more than 5 mm long
Lemmas 2, apically several-toothed
Lemmas 3 or more, mostly with a single apical notch
Lemmas 10-22 mm long
Lemmas 1.8-6 mm long
Glumes enclosing the rest of the spikelet
Lemmas extending well beyond the glumes
Lemma usually rounded on the back, strongly hairy towards the margins
Lemma keeled as a result of a prominent midrib, not strongly hairy towards the margins
Glumes distinctly longer than the individual lemmas
Glumes shorter than or about as long as the individual lemmas
Lemmas 1.5-2.5 mm long
Lemmas 3.5-6 mm long
Inflorescence open and sparse; lemmas usually hairy especially on veins and margins
Inflorescence contracted and dense; lemmas glabrous
Plants either male or female; occurs in wet, especially saline, habitats and has obviously 2-ranked leaves
Plants all bisexual; habitat various; leaves not obviously 2-ranked
Lemmas rounded on their back at least for much of their lower part
Lemmas keeled on their back as a result of at least one prominent midrib
Lemmas 2, thick and hard; spikelets dorsally compressed
Lemmas usually 3 or more, if only 2 then not thick and hard and spikelets laterally compressed
Lemmas 2; glumes 5-10 mm long
Lemmas usually 3 or more, if only 2 then at least 15 mm long
Glumes 16-33 mm long
Glumes up to 9 mm long
Glumes conspicuously different in length
Glumes equal or subequal in length
Lemmas 3-veined
Lemmas 5-7-veined
Lemmas more or less obtuse, 5-veined
Lemmas acute or, if somewhat obtuse, then 7-veined
Lemmas 3-veined; glumes 1-veined
Lemmas 5-7-veined; glumes 1-5-veined
Leaf sheaths fused to form a cylinder
Leaf sheath margins overlapping, not fused
Glumes about as long as wide
Glumes several times as long as wide
Spikelets sessile, in distinct spikes
Spikelets pedicellate or, if shortly pedicellate, not in distinct spikes
Glumes 9-14 mm long
Glumes up to 8 mm long
Ligule a membrane or ridge
Ligule of hairs or a hair-fringed membrane
Rhachilla not articulated; glumes not keeled
Rhachilla articulated below each lemma or, if not articulated, the glumes keeled
1st glume c. 0.2 mm long, rounded on its back
1st glume at least 0.7 mm long, keeled
Spikelets in compact clusters
Spikelets evenly spread through the inflorescence
Lemmas 2 in each spikelet
Lemmas 3 or more in each spikelet
Spike subtended by a leaf that exceeds it in length
Spike not subtended by a leaf