previous arrow
next arrow


Annual or perennial herbs, rarely shrubs or tall woody bamboos. Flowering stems (culms) jointed, internodes hollow or solid. Leaves arranged alternately in 2 ranks, differentiated into sheath, blade, and ligule, leaf-sheath split or infrequently tubular, modified with reduced blade in bamboos, leaf-blades divergent, usually long, narrow and flat, varying from inrolled and filiform to ovate, veins usually parallel, ligule membranous or a line of hairs. Inflorescence terminal or solitary, open, contracted, or spikelike panicle, or composed of lax to spike like raceme along an elongated central axis, or digitate, paired, or occasionally solitary, spikelets often aggregated into complex clusters in bamboos.

Key to the Genus

Serial Key Reference
1a. Herbaceous, usually with linear leaf-blades 2
1a. Bamboos with woody culms, commonly with lanceolate tessallately nerved leaf-blades 72 (Subfamily Bambusoideae)
2a. Spikelets1-to many-flowered; usually laterally compressed; breaking up at maturity above the persistent glumes, or if falling entire, then not 2-flowered with the lower floret male or barren and the upper bisexual 3 (Subfamily Pooideae)
2b. Spikelets 2-flowered; usually dorsally compressed; falling entire at maturity; usually with the upper floret bisexual and the lower floret male or barren, and if the later, often reduced to the lemma or rarely the lemma entirely absent, all alike or more often differing in size, shape and struture 29 (Subfamily Panicoideae)
3a. Palea 1-keeled, glumes absent or minute or rudimentary 4
3b. Palea 2-keeled, rarely 0-1 keeled and then glumes well-developed 8
4a. Spikelets articulate on their pedicels and deciduous without pedicels 5
4b. Spikelets deciduous with their pedicels 7
5a. Lower glume and upper glume minute or setaceous; lower lemma and upper lemma chartaceous Oryza
5b. Lower glume and upper glume absent; lower lemma and upper lemma membranous 6
6a. Leaf-blades linear; both lower and upper lemma broad; upper lemma not awned Leersia
6b. Leaf-blades elliptic; both lower and upper lemma narrow; upper lemma awned Hygroryza
7a. Glumes long-awned; inflorescence of spiciform raceme Perotis
7b. Glumes not awned; inflorescence of rigid erect spikes Zoysia
8a. Leaf-blades with distinct cross-nerves; broadly linear to ovate Centotheca
8b. Leaf-blades without evident cross-nerves 9
9a. Spikelets inserted in notches of a smiple spike 10
9b. Spikelets not as above 12
10a. Spikelets in triads at the nodes of the spike Hordeum
10b. Spikelets solitary at the nodes of the spike 11
11a. Plane of the spikelets radial to the axis Oropetium
11b. Plane of the spikelets tangential to the axis Triticum
12a. Spikelets strictly 1-flowered Sporobolus
12b. Spikelets 2-or more-flowered (rarely 1-flowered but then the inflorescence of racemes-Leptochloa) 13
13a. Inflorescence of a strongly compressed, cylindrical, continuous or interrupted catkin-like spike bearing spikelets in globose clusters Elytrophorus
13b. Inflorescence of open panicles or digitate or subdigitate spikes or racemes 14
14a. Inflorescence of an inarticulate spike or raceme with 2-seriate and secund spikelets, or of a spiciform panicle 15
14b. Inflorescence of open or contracted panicle, or if spicate not secund 21
15a. Spikelets on long, spiciform branches of a raceme Leptochloa
15b. Spikelets in simple digitate or simply racemed spikes 16
16a. Spikelets 1- flowered 17
16b. Spikelets 2- or more flowered 18
17a. Spikelets awnless; spikes digitate Cynodon
17b. Spikelets awned; spikes solitary, spicate or racemed Chloris
18a. Rachis of spike terminating in a fertile spikelet. Spike digitate or subdigitate Eleusine
18b. Rachis of spike not terminating in a spikelet, with or without rachis extension 19
19a. Spikes with rachis extension. Paired or digitate spikes Dactyloctenium
19b. Spikes without rachis extension 20
20a. Florets 2, dissimilar, the lower awnless, male or barren. Spikelets falling entire, subterete Arundinella
20b. Florets 2 to many, similar except the uppermost--which are gradually reduced Eriachne
21a. Large, stout plants with large compound panicles 22
21b. Plants shorter 25
22a. Spikelets with 1 fertile floret; rachilla produced beyond the upper floret Thysanolaena
22b. Spikelets with 2 or more fertile florets; rachilla not produced beyond the upper floret 23
23a. Rachilla glabrous; flowering glumes dorsally hairy beyond the middle Arundo
23b. Rachilla hirsute 24
24a. Lemmas glabrous Phragmites
24b. Lemmas penicillate with long hairs Neyraudia
25a. Lemmas 5-15 nerved; inflorescence of capitate or globular head of spikelets; leaves rigid, pungent Aeluropus
25b. Lemmas 1-3 nerved; inflorescence and leaves not as above 26
26a. Upper lemma indurated or crisply chartaceous Isachne
26b. Upper lemma membranous 27
27a. Racemes deciduous; glumes tapering to a long subulate awn Myriostachya
27b. Racemes persistent; glumes acute, not awned 28
28a. Spikelets sessile; falling entire Desmostachya
28b. Spikelets pedicelled, vaiously disarticulating; not falling entire Eragrostis
29a. Spikelets unisexual, with male and female spikelets in separate inflorescences or in different parts of the same inflorescence [Maydeae] 30
29b. Spikelets, or at least one of each pair, bisexual 32
30a. Internodes broader than and more or less enclosing female spikelet Zea
30b. Internodes narrower than and more or less enclosed by female spikelet 31
31a. Sheath subtending raceme herbaceous Chionachne
31b. Sheath subtending raceme indurated and forming an ovoid utricle around the female spikelet Coix
32a. Spikelets paired (except solitary in Dimeria and Arthraxon), one sessile and the other pedicelled, usually dissimilar with the pedicelled sometimes much reduced, rarely solitary and all alike; glumes as long as the spikelet and enclosing the florets, more or less rigid and firmer than the hyaline or membranous lemmas; upper lemma usually awned or reduced to an awn [Andropogoneae] 33
32b. Spikelets solitary or paired, more or less similar; glumes usually herbaceous or membranous, the lower smaller or sometimes suppressed; lower lemma generally resembling upper glume in structure and nervation; upper lemma papery to crustaceous, awnless or rarely mucronate [Paniceae] 54
33a. Spikelets not paired, unaccompanied by a vestige 34
33b. Spikelets paired, sometimes one of them vestigial i.e. imperfectly developed 35
34a. Raceme rachis tough, not jointed Dimeria
34b. Raceme rachis fragile, jointed Arthraxon
35a. Rachis internodes and pedicels stout, thickening upwards; upper lemma awnless; pedicels fused to internode, sometimes only in lower half or tip 36
35b. Rachis internodes and pedicels slender, sometimes thickened upwards but then the upper lemma awned or the callus rufously bearded; pedicels free from internodes 39
36a. Pedicelled spikelet absent Mnesithea
36b. Pedicelled spikelet present 37
37a. Rachis of raceme tough Hemarthria
37b. Rachis of raceme fragile 38
38a. Sessile spikelet globose Hackelochloa
38b. Sessile spikelet not globose Rottboellia
39a. Pedicelled spikelet similar to the sessile, both fertile 40
39b. Pedicelled spikelet differing from the sessile in shape and sex 43
40a. Inflorescence a panicle, with elongated central axis 41
40b. Inflorescence of single or subdigitate raceme 42
41a. Raceme rachis fragile; one spikelet of the pair sessile. Panicle ample Saccharum
41b. Raceme rachis tough; both the spikelets pedicelled Imperata
42a. Inflorescence axillary Pogonatherum
42b. Inflorescence terminal Eulalia
43a. Inflorescence a panicle with elongated central axis; raceme internodes never with a translucent median line 44
43b. Inflorescence of single or subdigitate racemes, sometimes with an elongated central axis but then raceme internodes with a translucent median line 46
44a. Lower glume of sessile spikelet dorsally compressed Sorghum
44b. Lower glume of sessile spikelet laterally compressed 45
45a. Raceme composed of several to many spikelet pairs; awns slender or inconspicuous Vetiveria
45b. Raceme reduced to a triad; awns usually prominent Chrysopogon
46a. Pedicels and internodes with a translucent median line 47
46b. Pedicels and internodes without a translucent median line 48
47a. Inflorescence a panicle; racemes of 1-5 (-8) sessile spikelets Capillipedium
47b. Inflorescence of single or subdigitate racemes, rarely paniculate and then racemes bearing more than 8 sessile spikelets Bothriochloa
48a. Lower floret of sessile spikelet male, with a palea 49
48b. Lower floret of sessile spikelet barren and reduced to a lemma 50
49a. Sessile spikelet dorsally compressed; racemes usually 2 or more Ischaemum
49b. Sessile spikelet laterally compressed; raceme single, spathate Apluda
50a. Lower glume of sessile spikelet 2-keeled; callus more or less inserted in hollowed internode tip 51
50b. Lower glume of sessile spikelet convexly rounded without keels, sometimes with a median groove but then the callus applied obliquely to the internode with its tip free 52
51a. Raceme single; lower glume of sessile spikelet more or less convex, the keels lateral to frontal, with intercarinal nerves Schizachyrium
51b. Racemes paired or digitate, rarely single and then the lower glume nerveless along the middle; lower glume of sessile spikelet concave or grooved between the keels Cymbopogon
52a. Raceme with 2 large homogeneous pairs at the base, forming an involucre Themeda
52b. Raceme with or without homogeneous pairs, if present not forming an involucre 53
53a. Sessile spikelet dorsally compressed, the callus obtuse Dichanthium
53b. Sessile spikelet subterete, the callus pungent Heteropogon
54a. Spikelets, singly or in clusters, subtended by 1 or more bristles, bracts or sterile spikelets and deciduous with them Pennisetum
54b. Spikelets not subtended by bristles, or if so these persistent on branches 55
55a. Upper lemma cartilagenous to chartaceous or rarely hyaline, the margins flat and usually hyaline 56
55b. Upper lemma coriaceous to bony at maturity with inrolled or flat margins, sometimes thinner but then margins inrolled 58
56a. Branches of the inflorescence ending in long bristles Pseudoraphis
56b. Branches of the inflorescence not ending in long bristles 57
57a. Inflorescence a panicle Hymenachne
57b. Inflorescence of racemes Digitaria
58a. Spikelets, at least those terminating a branch, subtended by 1 or more bristles, or the raceme rachis prolonged into an often obscure point 59
58b. Spikelets not subtended by bristles, nor raceme rachis prolonged into a subulate point 60
59a. Inflorescence usually a panicle, all or most of the spikelets subtended by bristles Setaria
59b. Inflorescence of racemes, only the terminal spikelet subtended by an inconspicuous bristle or point Paspalidium
60a. Spikelets strongly laterally compressed, distinctly gibbous Cyrtococcum
60b. Spikelets not or slightly gibbous 61
61a. Upper lemma without basal wings or scars Panicum
61b. Upper lemma with decurrent wings or scars at the base 62
62a. Spikelets supported on a globular bead Eriochloa
62b. Spikelets without a bead 63
63a. Inflorescence a panicle, sometimes irregularly contracted about the primary branches 64
63b. Inflorescence of more or less unilateral racemes, the spikelets usually single or paired but sometimes in irregular clusters or short secondary racemelets 65
64a. Upper lemma wiht a green crest Acroceras
64b. Upper lemma without a green crest Sacciolepis
65a. Glumes or lemmas awned 66
65b. Glumes and lemmas awnless or at most mucronate 68
66a. Spikelets laterally compressed, in 2 rows; awns often sticky Oplismenus
66b. Spikelets dorsally compressed 67
67a. Upper lemma awned, crisply chartaceous Alloteropsis
67b. Upper lemma awnless, coriaceous Echinochloa
68a. Lower glume absent, rarely minute 69
68b. Lower glume present 70
69a. Spikelets plano-convex, abaxial Paspalum
69b. Spikelets biconvex Axonopus
70a. Glumes equal, shorter than spikelet Ottochloa
70b. Glumes unequal, or both as long as spikelet 71
71a. Upper lemma mucronate; spikelets plano-convex, cuspidate Urochloa
71b. Upper lemma rarely mucronate, or if mucronate then spikelets plump Brachiaria
72a. Culms scandent. Spikelets with 2 florets; fruit a bacoid caryopsis Melocalamus
72b. Culm arborescent or shrubby 73
73a. Culmsheaths with 1 or 2 wavy bands above 2/3 of the length; pseudospikelets one sided in spicate flowering branch; culms widely spaced and distant; fruit a baccoid caryopsis, pear-shaped, long beaked Melocanna
73b. Culmsheaths with no wavy band; pseudospikelets either in whorls, semi-whorls or dense globose heads from the nodes of flowering branches; culms closely spaced; fruit a nucoid caryopsis 74
74a. Culmsheath top concavely depressed; branch bud ellipsoidal or rounded; top of the ovary gradually narrowed upwards into a hollow tube; culm wall up to 2 mm thick Schizostachyum
74b. Culmsheath top generally truncate or attenuate; branch bud ovate or triquetrous; top of the ovary more or less fleshy, not hollow, variously shaped; culm wall more than 4 mm thick 75
75a. Pseudospikelets either in compact globose heads or in semi-whorls at the nodes of flowering branches; florets closely set in pseudospikelets; rachilla not elongated; lodicules absent 76
75b. Pseudospikelets in clusters at the nodes of flowering branches; florets loosely arranged in pseudospikelets; rachilla internode distinctly elongate with a joint below the lemma attachment; terminal floret generally imperfect or rudimentary; lodicules 0- 3 77
76a. Culmsheaths with small naked auricles; branch bud narrowly ovate, slightly keeled towards apex; filament connate in a thin tube Gigantochloa
76b. Culmsheaths not auricled; branch buds triquetrous, not keeled; filaments free Dendrocalamus
77a. Palea alike, not bifid; lodicules 2-3; fruit top hairy; culmsheath with well-developed bristly auricles (not auricled in B. balcooa and B. multiplex) Bambusa
77b. Palea different, the lowest bifid; lodicules 0; fruit top glabrous; culmsheaths without auricles or if present very small Thyrsostachys