1	"Inflorescences of 1 or more spikes hae a distinct rachis; at least some spikes stalked but the stalks someimes only 2-5 mm long"	2
1	"Inflorescences of 1(2-5), usually dense head or, if more open, spikelets arranged in digitate clusters, not spikes"	31
2	"Plants without leaf blades; stems with transverse rings; plants perennial"	"Cyperus articulatus"
2	"Plants with the largest leaf blades more than 3 cm long or, if shorter, plants annual; stems without prominent transverse rings; plants perennial or annual"	3
3	"Styles with 2 branches; nutlets flattened"	4
3	"Styles with 3 branches; nutlets triangular"	7
4	"Plants annual, with minute root systems"	5
4	"Plants perennial, with woody rhizomes or stolons"	6
5	"Glumes with midribs excuttent, forming a prominent mucro"	"Cyperus hyalinus"
5	"Glumes obovate and obtuse"	"Cyperus macrostachyos"
6	"Plants with woody rhizomes, growing in marshes"	"Cyperus alopecuroides"
6	"Plants with slender stolons ending in bulbs, growing on sand dunes"	"Cyperus afrodunensis"
7	"Plants annual, with minute root systems; glumes 1.3-1.7 mm long"	8
7	"Plants perennial, with stolons, rhizomes, or slightly woody or hardened stem bases"	9
8	"Glumes elliptic, the midribs excurrent and forming a long mucro"	"Cyperus squarrosus"
8	"Glumes obovate to rounded, the midribs excurrent into a short mucro"	"Cyperus iria"
9	"Inflorescences composed fa single pike, without involucral bracts"	"Cyperus bulbosus"
9	"Inflorescences of few to many spikes in simple or compound umbellate structures or, if of only 1 spike, then at least some spikes with a leafy involucre"	10
10	"Basal sheaths semiscucculent producing bulbous, swollen bases; spikelets falling off intact when mature"	11
10	"Basal sheaths not succulent; spikelets sometimes with the rachilla persistent after the lower glumes are shed"	14
11	"Glumes 2.5-3 mm long, greyish white to greenish"	"Cyperus phillipsiae"
11	"Glumes 3-4 mm long, light to dark reddish brown"	12
12	"Leaf blades 0.2-0.6 mm wide, filiform"	"Cyperus chaetophyllus"
12	"Leaf blades 1-6 mm wide, flat"	13
13	"Glumes with midribs excurrent, forming a short, recurved mucro"	"Cyperus vestitus"
13	"Glume midribs not excurrent"	"Cyperus amauropus"
14	"Plants with slender stolons, sometimes ending in bulbs or tubers"	15
14	"Plants witout stolons; plant bases swollen or hardened, or stems arising from woody rhizomes"	25
15	"Plants with bulbs"	16
15	"Plants without bulbs, often with tubers"	18
16	"Bulbs formed below ground level; stems distant from the bulbs; spikelets 3-4 mm wide"	"Cyperus afrodunensis"
16	"Bulbs often formed at ground level; stems arising diretly from the bulbs; spikelets 1.5-2 mm wide"	17
17	"Spikelets dark reddish, 1.5-2 mm wide"	"Cyperus bulbosus"
17	"Spikelets tawn, 1.5-3 mm wide"	"Cyperus grandbulbosus"
18	"Spikelets falling intact when mature"	"Cyperus ferrugineoviridis"
18	"Spikelets remaining attached to the rachis but losing lower mature glumes and nutlets when mature"	19
19	"Stolons stout, rhizome-like, not ending in tubers; stem bases not greatly swollend"	"Cyperus longus"
19	"Stolons slender, frequently ending in small tubers or stem bases swollen"	20
20	"Spikelets with distant, obtuse glumes"	"Cyperus dilatatus"
20	"Spikelets with crowded, closely imbricate glumes"	21
21	"Spikelet rachillas not or scarcely winged"	"Cyperus procerus"
21	"Spikelet rachillas distinctly winged"	22
22	"Spikelets yellowish brown or rusty browj; glumes 2.2-2.6 mm long, with raised veins almost to the margins"	"Cyperus esculentus"
22	"Spikelets reddish brown or rusty brown; glumes 2.2-2.6 mm long, with a wide marginal border without veins"	23
23	"Glumes 2-3 mm long with a wide uncoloured margins"	"Cyperus maculatus"
23	"Glumes 2.7-4 mm long with a narrow uncoloured margin or such margin absent"	24
24	"Glumes without a pale marginal border or, if such a border is present, then glumes shorter than 3.5 mm"	"Cyperus rotundus"
24	"Glumes with a pale marginal boder, 3.5-4 mm long"	"Cyperus rubicus"
25	"Spikelets falling intact when mature"	"Cyperus hemisphaericus"
25	"Spikelets remaining attached to the rachis but losing lower mature glumes and nutlets when mature"	26
26	"Spike lengths less than twice spike widths, with few spikelets; largest spikelets often 15-40 mm long"	27
26	"Spike lengths at leat twice spike widths, often crowded; spikelets not more than 12 mm long when flowering"	29
27	"Spikelets less than 1 mm widel glumes 1.7-2.6 mm long"	"Cyperus distans"
27	"Spikelets 1-1.5 mm wide; glumes 2-3 mm long"	28
28	"Stem bases not prominently swollen"	"Cyperus longus"
28	"Stem bases prominently swollen"	"Cyperus maculatus"
29	"Glumes with rounded keels and inrolled margins"	"Cyperus alopecuroides"
29	"Glumes with distinct, green keels; margins not inrolled"	30
30	"Spikes 6-15 mm wide with 30-120 crowded spikelets; glumes 1.2-1.8 mm long"	"Cyperus dives"
30	"Spikes 15-25 mm wide often with only 15-30 rather distant spikelets; glumes 1.8-2.4 mm long"	"Cyperus exaltatus"
31	"Inflorescences rather open with spikelets in digitate clusters"	32
31	"Inflorescences congested into a solitary, usually desnse, cylindrical head, very rarely with 1-4 additional sessile or stalked heads"	71
32	"Basal leaves bladeless; inflorescence bracts often leafy"	33
32	"Lower leaves with blades"	35
33	"Involucral bracts leafy, numerous, and far exceeding the inflorescences"	"Cyperus alternifolius"
33	"Involucral bracts scale-like or, if leafy only 5-30 mm long"	34
34	"Major inflorescence branches all of equal length; stems without transverse rings"	"Cyperus prolifer"
34	"Major inflorescence branches of unequal length; stems with transverse rings"	"Cyperus articulatus"
35	"Glumes 1-2 mm long; styles with 2 branches; nutlets flattened or rounded"	36
35	"Glumes often more than 2 mm long; styles with 3 branches; nutlets triangular"	38
36	"Glumes 1.5-2 mm long, to a large extent whitish with large surface cells; nutlets about 1.2 mm long"	"Cyperus dwarkensis"
36	"Glumes 1-1.3 mm logn, reddish brown without prominent surface cells; nutlets 0.5-0.6 mm long"	37
37	"Glumes with excurrent midveins, conspicuously mucronate; nutlets obovate"	"Cyperus pumilus"
37	"Glumes with midveins ending below the tip, obtuase; nutlets broadly obovate to angular in outline"	"Cyperus micropelophilus"
38	"Plants annuals with minute root systems"	39
38	"Plants perennials with woody rhizomes or slender to tough stolons or stem bases swollen"	45
39	"Leaf blades prominently spirally twisted"	"Cyperus micromedusaeus"
39	"Leaf blades not prominently spirally twisted"	40
40	"Spikelets 3-5 mm wide; glumes 3.5-5 mm long"	"Cyperus compressus"
40	"Spikelets 0.8-2 mm wide; glumes 0.5-2 mm long"	41
41	"Glumes 0.5-0.8 mm long"	"Cyperus difformis"
41	"Glumes 1-2 mm long"	42
42	"Glumes truncate to emarginate with 3-veined midribs ending in a short or long recurved mucro; nutlets 0.5-0.8 mm long"	43
42	"Glumes oblong to ovate, obtuse with the midrib ending at t the top; nutlets 0.4-0.6 mm long"	44
43	"Glumes 1.5-2 mm long, including a long recirved mucro"	"Cyperus cuspidatus"
43	"Glumes 1.3-1.6 mm long with a very short mucro"	"Cyperus amabilis"
44	"Glumes straight; anther connectives setulose"	"Cyperus haspan"
44	"Glumes spreading; anther connectives smooth"	"Cyperus tenuispicus"
45	"Glumes 3.5-9 mm long"	46
45	"Glumes 0.5-3 mm long"	48
46	"Glumes 7-9 mm long, whitish to pale dirty brown; plants of low elevations, often on sandy sea shores"	"Cyperus crassipes"
46	"Glumes 3.5-5 mm long, grey, brown or reddish"	47
47	"Spikelets strongly compressed; plants often growing inland; plant bases not woody"	"Cyperus compressus"
47	"Spikelets not strongly compressed; plants only growing near the sea shore; plant bases woody"	"Cyperus frerei"
48	"Plants with stolons"	49
48	"Plants without stolons"	51
49	"Glumes 3-4 mm long; nutlets 1.6-1.8 mm long; stem bases succulent"	"Cyperus amauropus"
49	"Glumes 0.6-2 mm long; nutlets 0.6-0.9mm long; stem bases not succulent"	50
50	"Glumes 0.6-0.8 mm long"	"Cyperus difformis"
50	"Glumes about 2 mm long"	"Cyperus commixtus"
51	"Stem bases enclosed by semi-succulent basal sheaths producing oval to cylindric swollen bases"	52
51	"Stem bases not enclosed by semi-succulent leaf bases"	59
52	"Glumes 1.5-2.5 mm long"	53
52	"Glumes 3-6 mm long"	54
53	"Stem bases ovate and bulb-like; leaf blades not twised; glumes 1.5-1.8 mm long"	"Cyperus densibulbosus"
53	"Stem bases cylindrical; leaf blades prominently spirally twisted; glumes 2-2.5 mm long"	"Cyperus micromedusaeus"
54	"Largest spikelets at least 25 mm long; glumes 5-6 mm long"	"Cyperus assicaulis"
54	"Largest spikelets up to 20 mm long; glumes 3-4 mm long"	55
55	"Leaf blades flat, the largest 2-4 mm wide"	"Cyperus rubicundus"
55	"Leaf blades filiform, the largest 0.5-1.5 mm wide"	56
56	"Glumes 3-3.5 mm long; nutlets about 0.7 mm long an 0.5 mm wide"	"Cyperus baobab"
56	"Largest glumes usually 3.5-4 mm long; nutlets 1-1.5 mm long, 0.8-1.2 mm wide"	57
57	"Glumes ovate to ligulate with obtuse to retuse mucronate tips"	"Cyperus obbiadensis"
57	"Glumes triangular with acute, mucronate tips"	58
58	"Glume midribs prominently keeled and scabrous in upper half, excurrent, forming a 0.6-0.8 mm recurved mucro"	"Cyperus pseudosomaliensis"
58	"Glume midribs slightly keeled neat the tip, glabrous or with a few teeth, excurrent into a mucro shorter than 0.6 mm long"	"Cyperus cunduduensis"
59	"Glumes 1.3-2 mm long; leaf blades rather thin"	60
59	"Glumes 2.3-5 mm long; leaf blades thicker"	63
60	"Stems 5-10 cm tall, bases bulb-like"	"Cyperus densibulbosus"
60	"Largest stems 15-80 cm tall"	61
61	"Nutlets elliptic, about 1 mm long, 0,4 mm wide"	"Cyperus commixtus"
61	"Nutlets obovate to spherical"	62
62	"Stems 30-40 cm tall glumes 1.3-1.6 mm long; nutlets obovate triangular"	"Cyperus haspan"
62	"Stems 50-60 cm tall; glumes 1.5-2 mm long; nutlets obovate-triangular"	"Cyperus albomicroglumis"
63	"Spikelets 1-1.5 mm wide"	64
63	"Spikelets 2-5 mm wide"	65
64	"Glumes about 3.5 mm long; nutlets 1.1-1.3 mm long"	"Cyperus recurvispicatus"
64	"Roots without tomentum; nutlets about 1.5 mm long, compressed and curved"	"Cyperus mudugensis"
65	"Glumes 4-5 mm long"	66
65	"Glumes 2.5-4 mm long"	67
66	"Roots densely covered by tomentum; nutlets 1.8-2 mm long, triangular"	"Cyperus macrorrhizus"
66	"Roots without tomentum; nutlets about 1.5 mm long, compressed and curved"	"Cyperus benadirensis"
67	"Spikelets 4-6 mm long by about 2 mm wide"	"Cyperus somalidunensis"
67	"Largest spikelets up to 6 mm long and 2 mm wide"	68
68	"Roots densely covered by tomentum"	"Cyperus conglomeratus"
68	"Roots without tomentum"	69
69	"Glumes 2.5-3 mm long; spikelets 2-3 mm wide; nutlets triangular"	"Cyperus jeminicus"
69	"Glumes 3-5 mm long; spikelets 3-5 mm wide; nutlets compressed and prominently curved"	70
70	"Stems smooth; nutlets about 1.5 mm long"	"Cyperus benadirensis"
70	"Stems scabrous, at least on some ridges; butlets about 1.2 mm long"	"Cyperus scabricaulis"
71	"Inflorescences bright yellow"	"Cyperus niveus var. flavissimus"
71	"Inflorescences white or brownish"	72
72	"Inflorescences of 1 head of sessile spikelet subtended by 1-4 heads of stalked spikelets"	73
72	"Inflorescences of a solitary head of spikelets"	74
73	"Inflorescences with 1-2 stalked heads of spikelets; spikelets 3-5 mm long"	"Cyperus mogadoxensis"
73	"Inflorescences with 2-4 stalked heads of spikelets; spikelets 1-1.5 mm long"	"Cyperus pluricephalus"
74	"Leaf blades absent or very short; involucral bracts 1-2, often exceeded by the inflorescences"	75
74	"Leaf blades well developed; involucral bracts 2-many, greatly exceeding the inflorescences"	76
75	"Plants floating; stems strongly triangular; glumes 4.5-5.5 mm long"	"Cyperus colymbetes"
75	"Plants not floating; stems tereter to triangular; glumes 2-3.5 mm long"	"Cyperus laevigatus"
76	"Nutlets triangular to rounded; styles with 3 long branches, 2 short branches, or unbranched"	77
76	"Nutets flattened; styles with 2 long branches"	111
77	"Plants annuals with minute root systems"	78
77	"Plants perennials with rhizomes, stolons, or swollen stem bases"	82
78	"Glumes 0.6-0.8 mm long"	"Cyperus difformis"
78	"Glumes 1.3-5 mm long"	79
79	"Glumes 1.3-2 mm long, terminating in a long recurved mucro"	80
79	"Glumes 2.5-5 mm long, with or without a mucro"	81
80	"Spikelets 1.7-2 mm wide; glumes 1.6-2 mm long"	"Cyperus cuspidatus"
80	"Spikelets 2-3 mm wide; glumes 1.4-1.7 mm wide"	"Cyperus squarrosus"
81	"Stem bases not succulent; spikelets 10-50 mm long; glumes 3.5-5 mm long; nutlets 1.5-1.7 mm long"	"Cyperus compressus"
81	"Stemb bases succulent; spikelets 4-15 mm long; glumes 2.5-4 mm long; glumes 0.9-1.1 mm long"	"Cyperus rubicundus"
82	"Inflorescences light to dark reddish brown ot with large dark patches"	83
82	"Inflorescences white, sometimes drying to pale pinkish brown, with or without a few reddish brown spots"	102
83	"Plants with long stolons or horizontal rhizomes, growing from sea level to 150 m"	84
83	"Plants forming small clumps, without well defined rhizomes, growing from sea level to 2000 m"	86
84	"Spikelets 4-10 mm long; glumes 3-4 mm long"	"Cyperus chordorrhizus"
84	"Spikelets 10-40 mm long; glumes 4.5-8 mm long"	85
85	"Plants with scale-covered stolons; glumes 6-8 mm long, pale brown to white"	"Cyperus crassipes"
85	"Plants with horizontal rhizomes; glumes 4.5-5 mm long, reddish brown"	"Cyperus frerei"
86	"Glumes 1.3-1.5 mm long; nutlets 0.5-0.6 mm long, pear-shaped"	"Cyperus meeboldii"
86	"Glumes 2.3-6 mm long; nutlets 0.7-2 mm long"	87
87	"Glumes 5-6 mm long; nutlets about 2 mm ong"	"Cyperus poecilus"
87	"Glumes 2.5-4 mm long; nutlets 0.7-1.5 mm long"	88
88	"Nutlets as long as wide, compressed and curved or with 3 very concave faces"	89
88	"Nutlets longer than wide, obscurely to conspicuously triangular, not compressed"	91
89	"Stems evidently scabrous; leaf blades 2-3 mm wide"	"Cyperus scabricaulis"
89	"Stems smooth; leaf blades 0.5-2 mm wide"	90
90	"Leaf blades straight or curled only at the top; glumes 3-3.5 mm long; nutlets about 1.2 mm long and wide"	"Cyperus mogadoxensis"
90	"Basal leaf blades prominently and repeatedly curled; glumes 2-3 mm long; nultets 0.9-1 mm long"	"Cyperus medusaeus"
91	"Stem bases succulent, with fleshy leaf sheaths forming  ovate or cylindrical pseudobulbs"	92
91	"Stem bases not succulent but rhizomes sometimes thickened at the stem bases"	98
92	"Leaf blades flat, the largest 2-4 mm wide"	93
92	"Leaf blades usually filiform or canaliculate, the largest 0.3-1.5 mm wide"	95
93	"Spikelets 4-6 mm wide, not disarticulating before the glumes and nutlets are shed; nutlets 0.9-1.3 mm long"	"Cyperus rubicundus"
93	"Spikelets 1.5-4 mm wide, the glumes and nutlets disarticulating as a single unit; nutlets 1.6-1.8 mm long"	94
94	"Spikelets 4-5 mm long, 1.5-2 mm wide"	"Cyperus cruentus"
94	"Spikelets 5-17 mm long, 2-4 mm wide"	"Cyperus amauropus"
95	"Glumes 3-3.5 mm long; nutlets about 0.7 mm long and 0.5 mm wide"	"Cyperus baobab"
95	"Largest glumes usually 3.5-4 mm long; nutlets 1-1.5 mm long, 0.8-1.2 mm wide"	96
96	"Glumes ovate to ligulate, tips obtuse to retuse; midribs excurrent forming a mucro"	"Cyperus obbiadensis"
96	"Glumes triangular with acute, mucronate tips"	97
97	"Glume midribs prominently keeled and scabrous in upper half, excurrent, forming a 0.6-0.8 mm recurved mucro"	"Cyperus pseudosomaliensis"
97	"Glume midribs only slightly keeled neat the tip, smooth or with only a few teeth, excurrent into a very short mucro"	"Cyperus conduduenis"
98	"Spikelets about 1.5 mm wide; nutlets 0.8-1 mm long 0.4-0.5 mm wide"	"Cyperus mudugensis"
98	"Spikelets 2-4 mm wide; nutlets 1-1.5 mm long and 0.8-1.3 mm wide"	99
99	"Spikelets 4-6 mm long, with 5-9 flowers"	"Cyperus somalidunensis"
99	"Spikelets 5-30 mm long, with 10-50 flowers"	100
100	"Nutlets about 1 mm long, prominently triangular"	"Cyperus gypsophilus"
100	"Nutlets 1.2-1.5 mm long, obscurely triangular"	101
101	"Roots densely tomentose; spikelets compressed to subterete"	"Cyperus conglomeratus"
101	"Roots not tomentose; spikelets strongly compressed"	"Cyperus jeminicus"
102	"Plants with long stolons or horizontal rhizomes, growing from sea level to 150 m"	"Cyperus crassipes"
102	"Plants without stolons"	103
103	"Spikelets 4-25 mm long, with 8-30 flowers, the rachilla persistent after at least some of the lower glumes and nutlets have fallen"	104
103	"Spikelets 2-8 mm long, with 1-8 flowers, falling off as a single unit when mature"	109
104	"Glumes 0.8-1.6 mm long"	105
104	"Glumes 2-6 mm long"	107
105	"Leafy involucral bracts 5-8, longer than the stem; glumes 1.3-1.6 mm long"	"Cyperus pygmaeus"
105	"Leafy involucral bracts 2-3, much shorter than the stem; glumes 0.8-1.5 mm long"	106
106	"Glumes 1.3-1.5 mm long"	"Cyperus pulchellus"
106	"Glumes 0.8-1 mm long"	"Cyperus microglumis"
107	"Nutlets obscurely triangular and minutely papillose"	"Cyperus conglomeratus"
107	"Nutlets triangular, the adaxial side concave"	108
108	"Glumes 3-3.5 mm long"	"Cyperus somaliensis"
108	"Glumes 4-6 mm long"	"Cyperus niveus"
109	"Leaf blades 0.5-1 mm wide"	"Cyperus scleropus"
109	"Leaf blades 1.5-3.5 mm wide"	110
110	"Glumes 3.5-4 mm long"	"Cyperus paolii"
110	"Glumes 4-6 mm long"	"Cyperus dubius"
111	"Inflorescences composed of clusters of 5-10, easily discernable pale spikelets"	"Cyperus dwarkensis"
111	"Inflorescences composed of dense, globose or cylindrical heads of numerous crowded spikelets"	112
112	"Inflorescences white, cream or greenish white, sometimes greyish when mature, the color of dark mature nutlets visible through the thin glumes"	113
112	"Inflorescences yellow, gold, or greensh"	120
113	"Plants with long slender stolons"	"Cyperus purpureoglandulosus"
113	"Plants without stolons, sometimes rhizomatous"	114
114	"Glume keels winged, wings toothed"	"Cyperus alatus"
114	"Glume keels not winged, sometimes scabrous or hairy"	115
115	"Glume keels with long cilia; glumes up to 2 mm long"	"Cyperus welwitschii"
115	"Glume keels galabrous or scabrous with short, spikelike teeth"	116
116	"Spikelets about 1 mm long, producing 1 nutlet only; unbranched portion of the stules very short"	"Cyperus microstylis"
116	"Spikelets 3-8 mm long, perfeting 1-5 nutlets; unbranched part of styles usually long"	117
117	"Glumes not prominently keeled; mdribs disnct only near glume tip"	"Cyperus brunneofibrosus"
117	"Glumes keeled, midribs prominent from the base"	118
118	"Stem bases without remains of old leaf sheaths"	"Cyperus sesquiflorus subsp. appendiculatus"
118	"Stem bases enclosed by fibrous remains of old leaf sheaths"	119
119	"Glumes 4.5-7 mm long"	"Cyperus eximius"
119	"Glumes 3-4 mm long"	"Cyperus comosipes"
120	"Glume keels winged, wings toothed and hairy"	"Cyperus aureoalatus"
120	"Glume keels not winged, sometimes toothed, scabrous, or hairy"	121
121	"Plants tufted withou prominent horizontal rhizome; stem bases swollen and covered by the fibrous remains of old leaf sheaths"	"Cyperus oblongus subsp. jubensis"
121	"Plants without horizontal creeping rhizomes; stem bases without fibrous remains of old leaf sheaths"	122
122	"Glume keels smooth; involucral bracts 1-4; inflorescences often composed of a solitary, ovate or hemispherical head"	"Cyperus erectus"
122	"Glume keels toothed; involucral bracts 4-8; inflorescences composed of a head with 1 large and several smaller spikes"	"Cyperus aromaticus"