Key to Genera

1.

Culms woody; leaves pseudopetiolate

2

 

Culms usually herbaceous; if woody the leaves not pseudopetiolate

5

 
2.

Culms forming climbing vines

Mullerochloa

 

Culms not forming climbing vines

3

 
3.

Auricles with bristles to 10 mm long

Neololeba

 

Auricles without bristles

4

 
4.

Culms cylindrical in cross section

Bambusa

 

Culms with an internodal groove on alternate sides

*Phyllostachys

 

5.

Leaves spirally arranged

Micraira

 

Leaves arranged in two rows

6

 

6.

Spikelets morphologically or functionally unisexual

7

 

Spikelets bisexual

20

 

7.

Spikelets with 1 floret, or more than 2 florets

8

 

Spikelets with 2 florets

12

 

8.

Spikelets with 1 floret; male and female spikelets on same plant

9

 

Spikelets with more than 2 florets; male and female spikelets on different plants

10

 

9.

Lemma asymmetrical with a ±lateral orifice

Leptaspis

 

Lemma pyriform with a terminal orifice

Scrotochloa

 

10.

Short grasses with a compact raceme

 Distichlis

 

Tall reed-like grasses with a plumose panicle

11

 
11.

Leaf blades with only the midrib prominent and strongly sclerified

*Cortaderia

 

 Leaf blades with several wide strongly sclerified veins (including midrib)

*Austroderia        

 

12.

Upper lemma membranous, thinner than glumes

13

 

Upper lemma hardened, thicker than glumes

16

 

13.

Male and female spikelets in separate inflorescences

*Zea

 

Male and female spikelets in different parts of the same inflorescence

14

 

14.

Inflorescence consisting of a female spikelet enclosed in a rigid shell, from which a raceme of male spikelets emerges apically

Coix

 

Inflorescence spike-like with female spikelets basal and male apical

15

 
15.

Internode broader than and ± enclosing female spikelet

Chionachne

 

Internode narrower  than and ± enclosed by female spikelet

*Tripsacum

 

16.

Plants monoecioeus, i.e. with male and female spikelets on the same plant

17

 

Plants dioecious i.e. with male and female spikelets on different plants

18

 

17.

Inflorescence a simple raceme, with 1-2 female spikelets at the base, the upper spikelets male

Thuarea

 

Inflorescence a spike-like panicle with racemes of female spikelets below and solitary male spikelets above

Hygrochloa

 

18.

Inflorescence a contracted, spike-like panicle, not spatheate

Cenchrus

 

Inflorescences clustered together in dense, umbel-like spatheate heads

19

 

19.

Female heads with long stiff spines; inhabits coastal dunes

Spinifex

 

Female inflorescences bracteate but not spiny; inhabits desert sand dunes

Zygochloa

 

20.

Spikelets with 1 to many florets, if 2-flowered both florets or lower one bisexual

21

 

Spikelets 2-flowered, lower floret male or barren, upper bisexual or female

171

 

21.

Inflorescence a solitary bilateral spike or raceme; spikelets usually with the broad side facing the axis

22

 

Inflorescence a panicle or a unilateral or multilateral spike or raceme, rarely a bilateral spike but then the spikelets edgewise on to the axis

38

 

22.

Lemmas 3-5-nerved, hyaline to membranous

23

 

Lemmas 5-10-nerved, hardened at maturity

26

 

23.

Lemmas awned

*Psilurus

 

Lemmas not awned

24

 

24.

Spikelets compressed laterally

*Parapholis

 

Spikelets compressed dorsiventrally

25

 

25.

Lemmas with lateral nerves extending to the apex

Lepturus

 

Lemmas with very short lateral nerves

*Hainardia

 

26.

Rachilla terminated by a fertile floret

Tetrarrhena

 

Rachilla prolonged beyond the uppermost fertile floret

27

 

27.

Spikelets in groups of more than 2 at each rachis node

28

 

Spikelets solitary at each rachis node

30

 

28.

Spikelet 4-5-flowered, in groups of 2-4 (-7)

*Leymus

 

Spikelet 1-flowered, in groups of 2 or 3

29

 

29.

Spikelets in pairs at each rachis node

*Taeniatherum

 

Spikelets in 3s at each rachis node

*Hordeum

 

30.

Annuals

31

 

Perennials

34

 

31.

Glumes not keeled

Brachypodium

 

Glumes strongly keeled

32

 

32.

Glumes subulate

*Secale

 

Glumes not subulate

33

 

33.

Lemmas with nerves converging upwards

*Eremopyrum

 

Lemmas with nerves not converging upwards

*Triticum

 

34.

Rachis fragile, smooth

*Thinopyrum

 

Rachis tough, scabrous

35

 

35.

Plant with long creeping rhizomes

*Elytrigia

 

Plant tufted, or with short rhizomes

36

 

36

Leaf blades ± flat; glumes ± scabrous on nerves

Anthosachne

 

Leaf blades usually convolute or involute; glumes smooth

37

 

37.

Rachis internodes concave; glumes subacute to pointed

Australopyrum

 

Rachis internodes nearly flat; glumes truncate

*Thinopyrum

 

38.

Fertile lemmas deeply or distinctly lobed

39

 

Fertile lemmas entire, dentate or slightly lobed

42

 

39.

Spikelets 1-flowered

Amphipogon

 

Spikelets 2-or more-flowered, rarely 1-flowered

40

 

40.

Lemmas 9-lobed

Enneapogon

 

Lemmas 3-lobed

41

 

41.

Inflorescence a 1-sided raceme

Astrebla

 

Inflorescence a panicle or spike

Triodia

 

42.

Leaf blades hard, woody, needle-like

Triodia

 

Leaf blades not hard, woody, needle-like

43

 

43.

Leaf blades with transverse veins between main veins

44

 

Leaf blades without transverse veins

45

 

44.

Glumes more or less equal; upper glume 7-nerved; lemmas awned

Lophatherum

 

Glumes very unequal; upper glume 3-5-nerved; lemmas mucronate

Centotheca

 

45.

Tall reed-like plants

46

 

Plants not tall and reed-like

47

 

46.

Lemmas hairy; rachilla not hairy

*Arundo

 

Lemmas not hairy; rachilla hairy

Phragmites

 

47.

Spikelets with 2 or more bisexual florets or if only one, with rachilla extension or sterile florets (empty lemmas) above it

48

 

Spikelets with 1 bisexual floret, with or without male or sterile florets (empty lemmas) below it

132

 

48.

Spikelets with 3 or more florets or with 1or 2 florets and a rachilla extended beyond the upper floret

49

 

Spikelets with 2 florets, without a rachilla extension

122

 

49.

Inflorescence racemose or spicate, or digitate or non-digitate

50

 

Inflorescence a panicle

75

 

50.

Inflorescence digitate or subdigitate

51

 

Inflorescence racemose or spicate

62

 

51

Spikelet with at least 3 fertile florets

52

 

Spikelet with 1 (rarely 2) fertile florets

55

 

52.

Axis of each inflorescence branch ending in a bristle; spikelet-bearing axis disarticulating

Dactyloctenium

 

Axis of each inflorescence branch ending in a spikelet; spikelet-bearing axis not disarticulating

53

 

53.

Spikelets 2-5; lemma 5-7-nerved; leaves mostly basal, setaceous

Cyperochloa

 

Spikelets many; lemma 3-nerved; leaves not basally aggregated or setaceous

54

 

54.

Lemmas mucronate to shortly awned; upper glume 1-nerved

Acrachne

 

Lemmas muticous; upper glumes 3-7-nerved

*Eleusine

 

55.

Spikelet with 1 floret; lemmas unawned

56

 

Spikelet with 2 or more florets; lemmas awned

57

 

56.

Glumes shorter than floret

Cynodon

 

Glumes longer than floret

Brachyachne

 

57.

Lowest lemma dorsally compressed (lying on front or back when placed on a flat surface)

58

 

Lowest lemma laterally compressed (lying on the side when placed on a flat surface)

59

 

58.

Glumes unequal, shorter than florets

Enteropogon

 

Glumes subequal, longer than florets

Austrochloris

 

59.

Inflorescence with more than 40 branches

*Eustachys

 

Inflorescence with less than 20 branches

60

 

60.

Awn of lowest lemma less than 2 mm long

x Cynochloris

 

Awn of lowest lemma more than 3 mm long

61

 

61.

Lemmas very broad, wing-like

Oxychloris

 

Lemmas not very broad, not wing-like

Chloris

 

62.

Spikelets unilateral (borne on one side of the inflorescence axis)

63

 

Spikelets bilateral or multilateral (borne on opposite sides or all round the inflorescence axis)

70

 

63.

Spikelet with many fertile florets

64

 

Spikelet with one fertile floret

66

 

64.

Lower glume 5-nerved; lemma 7-nerved

Tribolium

 

Lower glume 1-nerved; lemma 1-3-nerved

65

 

65.

Lemma mucronate to shortly awned; spikelet rachilla and callus not hairy

Tripogon

 

Lemma awnless; spikelet rachilla and callus hairy

Eragrostiella

 

66.

One glume only developed

67

 

Both glumes well developed

68

 

67.

Spikelet with one floret; lemma 3-nerved

*Nardus

 

Spikelet with many florets; lemma 3-nerved

*Lolium

 

68.

Spikelets falling entire; spikelets 6-18 mm long

*Spartina

 

Spikelets fragmenting above glumes; spikelets less than 5.5 mm long

69

 

69.

Spikelets shortly pedicellate

*Mibora

 

Spikelets sessile

Microchloa

 

70.

Spikelets disarticulating above glumes; rachilla extending beyond upper floret

71

 

Spikelets falling with glumes; rachilla terminated by a floret

73

 

71.

Spikelets sessile, partially embedded in the rachis

*Gaudinia

 

Spikelets pedicelled, not embedded in the rachis

72

 

72.

Lemmas awned; glumes not keeled

*Vulpia

 

Lemmas awnless; glumes keeled

*Catapodium

 

73.

Inflorescence a true spike; spikelets sessile, sunken in hollows along the axis

*Pholiurus

 

Inflorescence a spike-like raceme or spike-like panicle; spikelets at least shortly pedicellate and not sunken in hollows

74

 

74.

Spikelets burr-like with hooked spines

Tragus

 

Spikelets not burr-like

Zoysia

 

75.

Glumes usually shorter than lowest floret and with the upper florets distinctly exserted; lemmas awnless or with a straight or curved awn from an entire or bifid apex, or several-awned or lobed

76

 

Glumes (or the longer one) at least as long as or longer than the lowest floret, often as long as the spikelet and enclosing the florets; lemmas awnless or more often awned from the back or from the sinus of a 2-lobed tip, the awn usually geniculate, rarely the awn straight or curved from the tip

106

 

76.

Lemmas 1-3-nerved

77

 

Lemmas 5-many nerved

88

 

77.

Lemmas 3-awned

Triraphis

 

Lemmas 1-awned or without awns

78

 

78.

Lemmas notched, toothed or lobed

79

 

Lemmas entire

83

 
79. Spikelets borne in leaf-sheath axils Psammagrostis
  Spikelets not borne in leaf-sheath axils 80
     
80. Lemma base often indurate, sometimes 5-nerved Disakisperma
  Lemma base soft and 3-nerved 81
     
81. Ligule apex acute to attenuate Diplachne
  Ligule apex usually trunate to obtuse 82
     

82.

Panicle branches arranged in racemes along rachis; ligule apex erose or entire but never ciliate

 Dinebra

 

Panicle branches digitate to sub-digitate inserted along
the rachis usually with two or more branches per node; ligule apex ciliate

Leptochloa

 

83.

Lemmas awned

84

 

Lemmas not awned

85

 

84.

Spikelets in globose clusters; palea winged

Elytrophorus

 

Spikelets in dense to loose panicles; palea not winged

Ectrosia

 

85.

Lemmas with winged keels

Heterachne

 

Lemmas without winged keels

86

 

86.

Ligule membranous

*Sphenopus

 

Ligule a fringe of hairs

87

 

87.

Lemmas 1-nerved

Thellungia

 

Lemmas 3-nerved

Eragrostis

 

88.

Ovary hairy at apex

89

 

Ovary glabrous at apex

91

 

89.

Leaf sheath margins joined

*Bromus

 

Leaf sheath margins free

90

 

90.

Leaf blades 7-24 mm wide; lemmas bilobed

Dryopoa

 

Leaf blades 2-3 mm wide; lemmas 3-lobed

Notochloë

 

91.

Spikelets dimorphous, with bisexual spikelets surrounded by sterile ones

92

 

Spikelets not dimorphous

93

 

92.

Spikelets disarticulating above the glumes; spikelet-bearing axes persistent

*Cynosurus

 

Spikelets disarticulating with the glumes; spikelet bearing axes disarticulating

*Lamarckia

 

93.

Inflorescence a contracted panicle or a panicle of racemes

94

 

Inflorescence an open panicle

98

 

94.

Glumes more or less equal

95

 

Glumes very unequal

97

 

95.

Glumes not keeled

*Melica

 

Glumes keeled

96

 

96.

Leaf blades up to 3 mm long and basal, if present

Spartochloa

 

Leaf blades well developed and not mainly basal

*Catapodium

 

97.

Glumes very dissimilar; lemmas awned

*Vulpia

 

Glumes similar; lemmas awnless

*Sclerochloa

 

98.

Spikelets almost as wide as long

*Briza

 

Spikelets up to half as wide as long

99

 

99.

Lemmas ± rounded or flattened on back, at least below

100

 

Lemmas keeled throughout

101

 

100.

Lemmas 7-9-nerved; leaf sheath margins joined

Glyceria

 

Lemmas 5-nerved; leaf sheath margins free

Puccinellia

 

101.

Leaves not basally aggregated; lemmas firmer than glumes, awned

102

 

Leaves mostly basal; lemmas similar in texture to glumes, awnless

103

 

102.

Lemmas keeled; palea thinner than lemma

*Dactylis

 

Lemmas not keeled; palea with similar texture to lemma

*Festuca

 
103 Lemma awned Hookerochloa
  Lemma unawned 104
     
104. Sheath of upper culm leaf with margins joined only at the nodal band; blades 4–15 mm wide, flat Sylvipoa
  Sheath of upper culm leaf with margins fused ≥1 mm or more above the nodal band; blades mostly <5 mm wide, flat to inrolled 105
     
105. Uppermost culm sheath margins fused 1–3% of the length Saxipoa
  Uppermost culm sheath margins fused 25–35% of the length Poa
     

106.

Ligule membranous

107

 

Ligule a fringe of hairs, ciliate membrane or ciliate at margins

116

 

107.

Lemmas 3-nerved

*Avellinia

 

Lemmas 5-9-nerved

108

 

108.

Lower floret male

*Arrhenatherum

 

Lower floret bisexual

109

 

109.

Glumes more than 14 mm long

*Avena

 

Glumes less than 10 mm long

110

 

110.

Annuals

111

 

Perennials

113

 

111.

Panicle spicate

 *Rostraria

 

Panicle open

 112

 
112.

Awn witha ring of hairs at junction of column and limb

*Corynephorus

 

Awn without a ring of hairs

*Aira

 

113.

Lemmas 4-pointed, or 2-lobed with each lobe 2-pointed

114

 

Lemmas entire, 2-pointed or 2-lobed but not as above

115

 

114.

Glumes long relative to the adjacent lemmas; leaves mostly basal

Deschampsia

 

Glumes shorter than the adjacent lemmas; leaves not basally aggregated

Amphibromus

 

115

Lemma awn 4-9 mm long, geniculate

Trisetum

 

Lemma awnless or with a short awn to 0.7 mm long

*Koeleria

 

116.

Leaf sheaths of the lower leaves swollen and woolly or leaf blades hard, woody, needle-like

117

 

Leaf sheaths of the  ower leaves not swollen and woolly and leaf blades not hard, woody, needle-like

118

 

117.

Spikelets with 3-8 fertile florets; leaf sheaths of the lower leaves swollen and woolly

Monachather

 

Spikelets with 1 fertile floret; leaf blades hard, woody, needle-like

Symplectrodia

 

118.

Lemmas awnless, sometimes mucronate

119

 

Lemmas distinctly awned

123

 

119.

Lemmas entire, if mucronate, mucros apical

*Tribolium

 

Lemmas bilobed; if mucronate, mucro is from an apical sinus

120

 

120.

Grain not longitudinally grooved

*Schismus

 

Grain longitudinally grooved

121

 

121.

Lemma only hairy on the lower margins

*Danthonia

 

Lemma ± evenly pubescent or in tufts

122

 

122.

Lemma ± evenly pubescent in lower half only/td>

Plinthanthesis

 

Lemma with hairs over whole surface or in tufts

Rytidosperma

 

123.

Hilum ± 1/2 length of grain

*Chionochloa

 

Hilum up to 1/3 length of grain

124

 

124.

Lemma ± evenly pubescent in lower half only

Plinthanthesis

 

Lemma with hairs over whole surface or in tufts

125

 

125.

Hairs on the lemma in two untidy rows, most of lemma surface glabrous and shiny; leaves often disarticulating from sheath

Rytidosperma

 

Hairs on the lemma forming a continuous indumentum, sometimes with tufts on the upper margin; leaves not disarticulating

126

 

126.

Lemmas either distinctly hairy or awned

127

 

Lemmas neither distinctly hairy nor awned

131

 

127.

Upper glume twice length of lower glume

Pheidochloa

 

Glumes ± equal in length

128

 

128.

Glumes (3-)5-11-nerved

Eriachne

 

Glumes 1-3-nerved

129

 

129.

Bisexual florets 1 per spikelet

*Holcus

 

Bisexual florets 2 per spikelet

130

 

130.

Lemma awn dorsal

Aira

 

Lemma awn terminal

*Pentameris

 

131.

Both lemmas membranous, not hardened

*Periballia

 

Lower lemma hardened

Coelachne

 

132.

Glumes absent or rudimentary

133

 

Glumes well developed

135

 

133.

Spikelets 1-flowered

Leersia

 

Spikelets 3-flowered, the lower two reduced to sterile lemmas

134

 

134.

Lemma and palea leathery to indurated

Oryza

 

Lemma and palea membranous

Potamophila

 

135.

Spikelets with 3 florets, the lower two reduced to sterile or male and sometime minute lemmas

136

 

Spikelets with 1 floret

140

 

136.

Both sterile lemma with a hinge-like appendage

*Ehrharta

 

Neither sterile lemmas with an appendage

137

 

137.

Basal florets male

Hierochloë

 

Basal florets sterile

138

 

138.

Glumes minute

Microlaena

 

Glumes relatively large

139

 

139.

Sterile lemmas shorter than fertile floret; glumes winged

*Phalaris

 

Sterile lemmas longer than fertile floret; glumes not winged

*Anthoxanthum

 
140. Glumes much longer than lemma and with long awns Perotis
  glumes usually shorter than lemma and if awned only slightly so 141
     

141.

Lemma terete or dorsally compressed

142

 

Lemma laterally compressed

149

 

142.

Lemma with a 3-branched awn (very rarely 1-branched)

143

 

Lemma with a single undivided awn

144

 
143.

Awns glabrous

Aristida

 

Awns plumose

*Stipagrostis

 

144

Awn ± geniculate; spikelet base (callus) pointed, often long and pungent

145

 

Awn ± straight; spikelet base (callus) short and blunt

148

 

145.

Lemma margins usually enclosing the palea; callus pungent; awn well developed and with a strongly-twisted column at maturity

146

 

Lemma margins not completely enclosing the palea; callus blunt; awns not as robust as above and the column only weakly developed at maturity

147

 

146.

Hummock-forming perennial; awn almost circular in transverse section

Monodia

 

Annuals or perennials, not usually hummock-forming; awn flattened in transverse section

Austrostipa

 

147.

Lemma apex and lower part of awn with hairs obscuring the base of the awn

Jarava

 

Lemma apex glabrous or slightly hairy, the hairs not obscuring the base of the awn

Amelichloa

 

148.

Lemma smooth, with a deciduous awn

*Piptatherum

 

Lemma strongly scabrous, with a more or less persistent awn

*Nassella

 

149.

Lemmas coriaceous to indurated

150

 

Lemmas membranous to cartilaginous

155

 

150

Lemma awns non-geniculate

151

 

Lemma awns geniculate

152

 

151.

Lemma with a 3-branched awn (very rarely 1-branched); spikelets with one floret

Aristida

 

Lemma with a single awn; spikelets with 2 florets (very rarely 1)

Eriachne

 

152.

Lemma 1 awned and with an apical crown

153

 

Lemma 3-5 awned and without an apical crown

154

 

153.

Awn at least 15 mm long; palea shorter than lemma, the lemma margins enclosing the palea

*Nassella

 

Awn less than 10 mm long; palea slightly longer than lemma, the lemma margins exposing the palea

*Piptochaetium

 

154.

Lemma with 5 awns

Pentapogon

 

Lemma with 3 awns

Anisopogon

 

155.

Glumes similar in texture to and shorter than lemmas; ligule hairy to some degree

156

 

Glumes firmer in texture to and as long as or longer than lemmas; ligule an unfringed membrane

157

 

156.

Panicle spike-like, subtended by an inflated sheath

*Crypsis

 

Panicle open to contracted, without an inflated sheath

Sporobolus

 

157.

Spikelets falling entire

158

 

Spikelets disarticulating above the glumes

160

 

158.

Glumes blunt, ±united

*Alopecurus

 

Glumes acute or awned, distinctly separate

159

 

159

Lemma 3-nerved

Garnotia

 

Lemma 5-nerved

Polypogon

 

160.

Glumes swollen at base

*Gastridium

 

Glumes not swollen at base

161

 

161.

Glumes silky-woolly, much longer than lemma

*Lagurus

 

Glumes not silky-woolly, equal to or slightly longer than lemmas

162

 

162.

Spikelets at least 9 mm long

*Ammophila

 

Spikelets up to 7 mm long

163

 

163.

Glumes terminating abruptly, shortly awned

164

 

Glumes obtuse or acute, not or scarcely awned

165

 

164.

Lemmas awned; inflorescence a contracted panicle

*Polypogon

 

Lemmas not awned; inflorescence a tight spike-like panicle

*Phleum

 

165.

Glumes with regularly arranged hairs on keel

Echinopogon

 

Glumes smooth to rough on keel, without hairs

166

 

166.

Lemma awns more than twice as long as lemma

167

 

Lemma awns, if present, less than twice as long as lemma

168

 
167.

Annuals

*Apera

 

Perennials

Dichelachne

 

168.

Lemmas decidedly firmer than the glumes

Deyeuxia

 

Lemmas less firm than the glumes

169

 

169.

Glumes at least 5.5 mm long

*Calamagrostis

 

Glumes less than 5 mm long

170

 

170.

Inflorescence axis persistent; rachilla extension less than 20% of lemma length

Agrostis

 

Inflorescence often detaching as a diaspore; rachilla extension 30-100% of lemma length

Lachnagrostis

 

171.

Spikelets breaking up above the glumes

172

 

Spikelets falling entire, breaking below the glumes

173

 

172.

Glumes very unequal; spikelets compressed laterally

Arundinella

 

Glumes ±equal; spikelets compressed dorsiventrally

Isachne

 

173.

Spikelets often dissimilar and usually paired, with one sessile and the other pedicelled (occasionally both pedicelled, but unequally, or in 3's with 2 sessile and 1 pedicelled) or rarely with the pedicelled spikelet reduced to the pedicel; upper lemma of sessile spikelet usually geniculately awned; glumes firm in texture

174

 

Spikelets all alike and usually solitary, rarely paired; upper lemma not geniculately awned; glumes usually membranous

210

 
174.

 Spikelets similar in shape and size, development of awns and sex; if different pedicelled spikelets awned and sessile unawned; pedicels and raceme joints slender

175

 

Spiklets different in shape and size, development of awns and sex; if similar, pedicels and joints thickened

183

 

175.

Paired spikelets unequally pedicelled

176

 

Paired spikelets with at least one sessile

178

 

176.

Spikelets awnless

Imperata

 

Spikelets awned from apex of the upper lemma

177

 

177.

Inflorescence a panicle, the racemes at least 10 cm long

*Miscanthus

 

Inflorescence of subdigitate racemes up to 7 cm long

Pseudopogonatherum

 

178.

Inflorescence a much branched panicle

Saccharum

 

Inflorescence a solitary raceme, or a digitate or subdigitate cluster of racemes

179

 

179.

Spikelets in 3s, with 2 sessile and 1 pedicelled

Polytrias

 

Spikelets in pairs (3s at apex), with 1 sessile and 1 pedicelled

180

 

180.

Sessile spikelets male; pedicelled spikelets female

Germainia

 

Sessile and pedicelled spikelets of the same sex

181

 

181.

Lower glume convex on back, not 2-keeled

Pogonatherum

 

Lower glume flat or grooved on back,2-keeled

182

 

182.

Tufted grass with silky hairs on racemes

Eulalia

 

Creeping grass with no hairs on racemes

Leptatherum

 

183.

Rachis joints and pedicels thick, ± contiguous or fused together, forming cavities into which the spikelets are sunk

184

 

Rachis joints and pedicels slender, or if thickened upwards, not forming cavities

192

 

184.

Sessile spikelet awned

185

 

Sessile spikelet awnless

187

 

185.

Pedicelled spikelets reduced to naked pedicels

Thelepogon

 

Pedicelled spikelets developed

186

 

186.

Pedicels ± flat

Sehima

 

Pedicels swollen

Ischaemum

 

187.

Lower glume of sessile spikelet 2-toothed

Elionurus

 

Lower glume of sessile spikelet not 2-toothed

188

 

188.

Spikelets in opposite rows on axis 

Ophiuros
 

Spikelets on one side of axis

189

 

189.

Spikelets of each pair similar, both bisexual; rachis not fragmenting

Hemarthria

 

Spikelets of each pair dissimilar, pedicelled male or sterile or spikelets borne singly; rachis fragmenting readily

190

 

190.

Lower floret of sessile spikelet male

Rottboellia

 

Lower floret of sessile spikelet sterile

191

 

191.

Lower glume of sessile spikelet with a row of marginal spines

Eremochloa

 

Lower glume of sessile spikelet without marginal spines

Mnesithea

 

192.

Inflorescence with spathes, spatheoles or spathe-like sheaths enclosing or subtending inflorescence

193

 

Inflorescences  espatheate

201

 

193.

Raceme 1 jointed, reduced to 3 spikelets

194

 

Racemes with several joints, with more than 3 spikelets

195

 

194.

Racemes in tight clusters; lemmas mucronate or shortly awned

Apluda

 

Racemes loose and pedunculate; lemmas with long awns

Clausospicula

 

195.

Fertile spikelets ±compressed, the lower glume distinctly 2-keeled for most of its length

196

 

Fertile spikelets ±terete, the lower glume 2-keeled only at the tip if at all

199

 

196.

Lower part of awn as wide as the lemma from which it arises

Spathia

 

Lower part of awn narrower than the lemma from which it arises

197

 

197.

Raceme bases terete

*Andropogon

 

Raceme bases flattened

198

 

198.

Racemes paired; leaves aromatic

Cymbopogon

 

Racemes solitary; leaves not aromatic

Schizachyrium

 

199.

Fertile spikelets not within an involucre of male or barren spikelets

Hyparrhenia

 

Fertile spikelets within an involucre of male or barren spikelets

200

 

200.

Fertile spikelets falling with involucre or whole raceme falling as one unit; callus blunt

Iseilema

 

Fertile spikelets falling separately from involucres; callus pungent

Themeda

 

201.

Rachis joints and pedicels with a translucent mid-line between thickened margins

202

 

Rachis joints and pedicels without a translucent mid-line

203

 

202.

Inflorescence more than once-branched

Capillipedium

 

Inflorescence an arrangement of racemes on a central axis

Bothriochloa

 

203.

Inflorescence of solitary, paired or subdigitate racemes

204

 

Inflorescence a panicle

206

 

204.

Creeping plant with ovate leaves

Arthraxon

 

Erect plant with linear leaves

205

 

205

Fertile spikelet ±cylindrical in cross-section; callus pungent

Heteropogon

 

Fertile spikelet ±compressed; callus not pungent

Dichanthium

 

206.

Spikelets laterally compressed

Chrysopogon

 

Spikelets dorsally compressed or ±cylindrical

207

 

207.

Pedicelled spikelet reduced to pedicel; panicle axes not terminating in spikelets

*Sorghastrum

 

Pedicelled spikelet developed, rarely reduced or suppressed but then panicle axes terminating in spikelets

208

 

208.

Pedicelled spikelets reduced to narrow, linear glumes; culm nodes glabrous or pubescent, not bearded

Vacoparis

 

Pedicelled spikelets usually well developed, rarely greatly reduced or absent, but then culm nodes bearded with stiff hairs

209

 

209.

Lemma awns of sessile spikelet absent or 1-1.5 cm long if present

Sorghum

 

Lemma awns of sessile spikelet 2-9 cm long

Sarga

 

210.

Inflorescence a spike or spike-like raceme or digitate pair of racemes; glumes as long as or longer than the florets

211

 

Inflorescence otherwise or if a spike or raceme lower glume shorter than the florets

216

 

211.

Inflorescence of paired racemes (with rarely a third raceme)

Dimeria

 

Inflorescence a single spike or raceme

212

 

212.

Inflorescence a spike

Thaumastochloa

 

Inflorescence single raceme

213

 

213.

Spikelets with distinct bristles from confluent tubercles

Thyridolepis

 

Spikelets with indistinct bristles from single tubercles, sometimes densely hairy

214

 

214.

Plant shortly rhizomatous

Neurachne

 

Plant stoloniferous

215

 
215.

Annuals

Thedachloa

 

Perennials

Paraneurachne

 

216.

Spikelets with awns arising from between apical lobes of upper glume and lower lemma

*Melinis

 

Spikelets awnless or with awn arising terminally from lemmas or glumes

217

 

217.

Spikelets in bunches subtended by bracts

Xerochloa

 

Spikelets not in bunches subtended by bracts

218

 

218.

Terminal spikelets opening normally; axillary spikelets cleistogamous

219

 

All spikelets opening normally

221

 

219.

Cleistogamous  spikelets enclosed in semi-woody to woody leaf sheath

Calyptochloa

 

Cleistogamous spikelets not enclosed as above

220

   
220.

Lower lemma of cleistogamous spikelets woody, >0.05 mm thick

Cleistochloa

 

Lower lemma of cleistogamous spikelets cartilaginous,< 0.05 mm thick

Dimorphochloa

 

221.

Fertile lemma densely silky hairy

Entolasia

 

Fertile lemma not or indistinctly hairy

222

 

222.

Inflorescence with broad, flattened axis with spikelets on one or both sides

223

 

Inflorescence otherwise

224

 

223.

Spikelets closely spaced on one side of inflorescence axis

Stenotaphrum

 

Spikelets in distinct clusters on both sides of inflorescence axis

Uranthoecium

 

224..

Inflorescence branches ending in bristle-like appendages or spikelets subtended by bristles

225

 

Inflorescence branches ending in spikelets which are not subtended by bristles

232

 

225.

Spikelets falling at maturity without any bristles or spines attached

226

 

Spikelets falling at maturity with bristles or spines attached

229

 

226.

Spikelets subtended by solitary bristles or an involucre of bristles

Setaria

 

Spikelets in racemes terminating in bristle-like appendages

227

 

227.

Lower palea with wings clasping margin of upper floret

Holcolemma

 

Lower palea not winged, not clasping upper floret

228

 

228.

Upper lemma covered with wrinkles, as long as or longer than upper glume

Paspalidium

 

Upper lemma smooth, shorter than upper glume

Pseudoraphis

 

229.

Spikelets completely surrounded by a ring of spines or bristles

Cenchrus

 

Spikelets not surrounded by spines or bristles

230

 

230.

Lower glume up to 1/3 spikelet length

Chamaeraphis

 

Lower glume more than 1/3 spikelet
length

231

 
231. Primary inflorescence branch producing simple unbranched bristles, each accompanied by a spikelet; rachilla between the glumes not distinct; pedicels less than 0.5 mm long Paractaenum
  Primary inflorescence branch producing 2–3 spikelets with each spikelet subtended by branched bristles; rachilla between the glumes distinct; pedicels 1.2–3.4 mm long Plagiosetum
     

232.

Upper glume and lower lemma with hooked hairs

Ancistrachne

 

Upper glume and lower lemma without hooked hairs

233

 

233.

Spikelet with a bead-like swelling at base

Eriochloa

 

Spikelet without a bead-like swelling at base

234

 
234.

Upper lemma with a shallow excavation and tuft of wool at the tip

*Lasiacis

 

Upper lemma rarely excavated and then not woolly

235

 

235.

Fertile lemma less firm or similar in texture to glumes

236

 

Fertile lemma decidedly firmer than the glumes

243

 

236.

Lower glume 2/3 spikelet length

237

 

Lower glume to 1/2 spikelet length or absent

238

 

237.

Inflorescence branches stiff and spreading; palea notched with a central depression

Walwhalleya

 

Inflorescence consisting of only a few spikelets, with branches not stiff and spreading; palea apex not notched

Alexfloydia

 

238.

Upper glume mucronate to shortly awned

Alloteropsis

 

Upper glume obtuse to acuminate, not awned or mucronate

239

 

239.

Palea of upper floret not completely clasped by lemma

240

 

Palea of upper floret completely clasped by lemma

241

 

240.

Spikelet laterally compressed

Dallwatsonia

 

Spikelet dorsally compressed

Hymenachne

 

241.

Lower glume minute or absent; spikelet dorsally compressed

Digitaria

 

Lower glume c. 1/3 spikelet length; spikelet terete or ±laterally compressed

242

 

242.

Lower glume minute or absent; spikelet dorsally compressed

Digitaria

 

Spikelet terete or ± laterally compressed

Steinchisma

 

243.

Rachilla prominent between glumes and between florets

244

 

Rachilla not prominent between glumes and between florets; fertile florets without appendage at base

247

 

244.

Rachilla swollen beneath fertile florets and usually with lateral appendages

245

 

Rachilla not swollen beneath fertile florets and without lateral appendages

246

 

245.

Appendages fused to base of fertile floret; spikelets laterally compressed, shortly pedicelled

Ichnanthus

 

Appendages, when present, free from base of fertile floret or absent; spikelets dorsally compressed, long pedicelled

Yakirra

 

246.

Articulations present at the bases of spikelets, pedicels and inflorescence branches; upper glume 11-nerved

Arthragrostis

 

Articulations absent on pedicels and inflorescence branches; upper glume 5-7-nerved

Whiteochloa

 

247.

Inflorescence an open or contracted panicle branched more than once; spikelets not grouped along one side of ultimate branches

248

 

Inflorescence once branched, the branches digitate or borne on elongated axis; spikelets grouped along one side of branches

255

 

248

Glumes slightly unequal in length

249

 

Glumes very unequal in length

251

 

249.

Spikelets 4.5-6 mm long, borne at the ends of long branches

Homopholis

 

Spikelets 0.2-2 mm long, on short branches

250

 

250.

Upper glume 3-nerved; spikelets falling with glumes and compressed laterally

Cyrtococcum

 

Upper glume 5-9-nerved; spikelets disarticulating above glumes and compressed dorsally

Isachne

 

251.

Inflorescence a spike-like panicle

Sacciolepis

 

Inflorescence an open panicle

252

 

252.

Upper glumes somewhat shorter than spikelet

Ottochloa

 

Upper glume as long as spikelet

253

 
253.

Fertile floret smooth and shiny

Panicum

 

Fertile floret transversely rugose

255

 
254.

Culm base bulbous

*Zuloagaea

 

Culm base not bulbous

*Megathyrsus

 

255.

Lower glume absent or represented by a minute scale

256

 

Lower glume present

257

 

256.

Lower lemma adjacent to the inflorescence axis

*Axonopus

 

Lower lemma positioned away from the inflorescence axis

Paspalum

 

257.

Spikelets awnless or mucronate

258

 

Spikelets distinctly awned

259

 

258.

Upper lemma rugose and verrucose

Moorochloa

 

Upper lemma smooth

Urochloa

 

259.

Glumes more or less equal and similar; decumbent grass of shaded habitats

Oplismenus

 

Glumes very unequal and dissimilar; erect grass of wet habitats

Echinochloa

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith