PlantNET Home PlantNET Home | Search NSW Flora | Contact Us  
FloraOnline
Introduction
Plant Name Search
Index Search
Spatial Search
Identification Keys
Classification
Glossary
HerbLink (Type Images)
WeedAlert
Other PlantNET Sites
Other Data Sources
NEW SOUTH WALES FLORA ONLINE Printable Page

Genus Cyperus Family Cyperaceae

Description: Annual or perennial herbs, tufted or rhizomatous, rarely tuber-bearing. Culms triquetrous to terete, nodeless.

Leaves sometimes reduced to sheaths; ligule present or absent.

Inflorescence simple or compound, umbel-like or head-like, rarely reduced to one spikelet; involucral bracts mostly leaf-like. Spikelets many- or few-flowered, flattened or terete, spicate or digitate at the ends of the ultimate branches or sometimes occupying the whole of the ultimate branches. Rachilla straight or flexuous, often bordered by hyaline or coloured membranous wings. Glumes distichous (very rarely spiral), concave or keeled, keel usually green, all except the lowest 2 or 1 subequal and containing bisexual flowers or the terminal one sometimes male. Hypogynous bristles absent. Stamens 1–3. Style 2- or 3-fid, continuous with ovary, not thickened at base, deciduous.

Nut trigonous or lenticular, glabrous, smooth or punctulate, rarely coarsely reticulate or transversely elongated.


Habit
Photo J. R. Hosking

Flower
Photo John R. Hosking

Distribution and occurrence: World: c. 600 species, cosmopolitan. Australia: c. 150 species (c. 50 species endemic), all States.

This genus is taken here in the broad sense to include species sometimes assigned to segregate genera such as Kyllinga and Pycreus. The tribe Cypereae is undergoing further study to assess whether segregate genera (including Lipocarpha) should be accepted.

Text by K. L. Wilson (1993, edited May 2009, March 2014)
Taxon concept:

Taxa not yet included in identification key
Cyperus bracheilema,    Cyperus curvistylis,    Cyperus isabellinus,    Cyperus prolifer,    Cyperus semifertilis

 Key to the species 
1Style 3-fid; nut more or less trigonous2
Style 2-fid; nut lenticular, biconvex, plano- or concavo-convex101
2Dwarf annuals smelling of fenugreek (at least when dried)3
Annuals or perennials but not smelling of fenugreek
                       Back to 1
4
3Spikelets flattened, with glumes arranged distichously; nut a third to half as long as glumeCyperus squarrosus
Spikelets more or less angular, with glumes arranged spirally; nut about two-thirds as long as glume
                       Back to 2
Cyperus hamulosus
4Spikelets with 4 or more flowers, flattened and with glumes overlapping at least a quarter the length of the glume immediately above on the same side of the rachilla and often spreading widely (at least at maturity)5
Spikelets 1–3-flowered, or up to 16-flowered but then terete and with glumes remote (i.e. with glumes not or scarcely overlapping the glume immediately above on the same side of the rachilla) and closely appressed to rachilla
                       Back to 2
91
5Spikelets arranged spicately on the rachis of the ultimate branches of the inflorescence, in very short to elongated spikes6
Spikelets digitately or subdigitately clustered, in clusters sometimes dense on a much reduced rachis, sometimes very few in number or solitary and then often appearing lateral when the lowest bract is erect
                       Back to 4
35
6Culms 2–5 m high; inflorescence with 100–250 primary branches of similar lengthCyperus papyrus
Culms less than 2 m high; inflorescence with fewer than 15 primary branches, usually of varying length
                       Back to 5
7
7Rachilla of the spikelet distinctly winged, the wings sometimes falling later8
Rachilla not winged or with very narrow wings
                       Back to 6
25
8Involucral bracts (and associated branches) distinctly separated on axis from neighbouring bracts by up to 3 mm; perennial producing numerous globose, bulb-like tubers with deciduous stiff, smooth, shining, blackish coatsCyperus bulbosus
Involucral bracts and branches inserted very closely together; perennials, rarely producing tubers and these grey-brown, oblong or ellipsoid or globose, with more or less persistent fibrous, dull, yellow-brown to grey-brown coats
                       Back to 7
9
9Spikelets less than 20 per spike10
Spikelets usually more than 20 per spike, numerous to very numerous
                       Back to 8
19
10Spikelets more than 1.5 mm wide in side view, more or less flattened; plants mostly with tuber-bearing rhizomes11
Spikelets 1–1.5 mm diam., flattened to terete; rhizome, if present, not tuber-bearing
                       Back to 9
18
11Perennials with short rhizome not tuber-bearing; glumes pale red-brown with broad white or yellowish margins or yellow-brown to dark golden brown or straw-coloured tinged red-brown; spikelets suberect or spreading in loose hemispherical to globose clusters12
Perennials with slender, creeping rhizomes producing fibrous-coated tubers 5–10 mm diam.; glumes orange-brown to dark red-brown or yellow-brown, with narrow hyaline or whitish margins; spikelets spreading in short, broad-cylindrical spikes
                       Back to 10
15
12Glumes pale red-brown with broad white or yellowish margins; spikelets suberect and held close to rachis in long, narrow-cylindrical spikesCyperus nutans
Glumes yellow-brown to dark golden brown or straw-coloured tinged red-brown; spikelets spreading in loose hemispherical to globose clusters
                       Back to 11
13
13Spikelets 1.2–2 mm wide in side view; inflorescence compound; nut very narrow-ellipsoidCyperus betchei
Spikelets 2–4.5 mm wide in side view; inflorescence usually simple; nut obovoid to broad-ellipsoid
                       Back to 12
14
14Nut grey to black; glumes with excurved mucro 0.3–0.8 mm longCyperus clarus
Nut yellow-brown; glumes with straight mucro 0.1–0.3 mm long
                       Back to 13
Cyperus fulvus
15Culms terete below, trigonous near the apex; leaves rarely half as long as culms; lowest involucral bract erect, very much exceeding the inflorescence, usually pushing it to one side; nut when mature 2–3 times as long as broad; freely fruitingCyperus victoriensis
Culms trigonous throughout their length; leaves mostly a half to three-quarters as long as culms; inflorescence symmetrical; nut either c. 1.5 times as long as broad or rarely maturing
                       Back to 11
16
16Rachis of spikes often spinulose; spikelets 5–12 mm long, obtuse; glumes yellow to dark golden brown, 3–5-nerved on each side, very obtuse; tubers globose to ovoid, with grey tomentum at maturity; rhizomes yellow-brownCyperus esculentus
Rachis of spikes usually not spinulose (occasionally sparsely so); spikelets 10–30 mm long, acute or obtuse; glumes red-brown to dark red-brown, with up to 3 nerves on each side, obtuse or acute; tubers more or less ellipsoid, without tomentum; rhizomes purplish to dark brown
                       Back to 15
17
17Lowest involucral bract shorter or not much longer than the inflorescence; spikelets c. 2 mm wide when mature; glumes usually dark red-brown, obtuse; the midrib faintly curved and recurved in side view from base to apex; fruit rarely maturing; fibrous coats of tubers soon disintegrating, not usually persisting beyond the first yearCyperus rotundus
Lowest bract much exceeding the inflorescence; spikelets 2.5–3 mm wide in side view when mature; glumes various shades of brown, rarely very dark, acute; midrib straight in side view from immediately above the base to the apex; nut c. 1.5 times as long as broad, obovate to elliptic-obovate; freely fruiting; fibrous coats of tubers often persisting into the second year
                       Back to 16
Cyperus bifax
18Inflorescence compound; glumes yellow-brown; nut 1.9–2.2 mm long, nearly as long as glumeCyperus betchei
Inflorescence simple; glumes red-brown or greenish tinged red-brown; nut 1.2–1.7 mm long, about half as long as glume
                       Back to 10
Cyperus subulatus
19Glumes 1–1.5 mm longCyperus exaltatus
Glumes 2–6.5 mm long
                       Back to 9
20
20Leaves and bracts septate-nodulose (often only obvious when dried)21
Leaves not septate-nodulose
                       Back to 19
23
21Terminal spikes cylindrical or ovate-cylindrical, laterals smaller, divergent or deflexed22
Terminal spikes hemispherical to globose, usually dense, 1–2 cm wide in side view; glumes 2–2.5(–3) mm long
                       Back to 20
Cyperus gunnii
22Glumes 4–6.5 mm long, red-brown; spikelets 4–10-floweredCyperus lucidus
Glumes 2.5–4 mm long, pale brown; spikelets 2–5-flowered
                       Back to 21
Cyperus vorsteri
23Spikelets 10–28 mm long, 8–24-flowered; tufted perennial, often apparently annual, often without any rhizomeCyperus congestus
Spikelets 6–15 mm long, 7–14-flowered; rhizomatous perennial; rhizome short and thick
                       Back to 20
24
24Glumes pale red-brown, with midrib green, 2–2.5 mm long; spikelets suberect, 1.5–2.0 mm wide in side viewCyperus nutans
Glumes whitish to pale brown on the sides, 3–3.5 mm long; spikelets spreading, 2–2.5 mm wide in side view
                       Back to 23
Cyperus rigens
25Glumes obtuse in side view but sometimes apparently acute because of the presence of a short mucro26
Glumes more or less acute in side view
                       Back to 7
29
26Glumes 1–2 mm long; spikelets flattened; tufted annualCyperus iria
Glumes 2–3.5 mm long; spikelets flattened or terete; rhizomatous perennials
                       Back to 25
27
27Glumes without broad whitish margins, short-mucronate; bracts and leaves septate-nodulose in the dried state, thick-textured; spikes rather dense28
Glumes with broad whitish margins above; bracts and leaves not septate-nodulose, thin-textured; spikes broad-ovoid, loose
                       Back to 26
Cyperus procerus
28Nut red-brown, minutely tuberculate; leaves to 12 mm wideCyperus alterniflorus
Nut yellow-brown, smooth to colliculate; leaves to 7 mm wide
                       Back to 27
Cyperus gunnii
29Rachis minutely and densely hispidCyperus pilosus
Rachis not hispid
                       Back to 25
30
30Glumes white to dark golden brown or straw-coloured tinged red-brown31
Glumes red-brown
                       Back to 29
34
31Glumes with excurved mucro 0.3–1 mm long32
Glumes without mucro, or mucro straight and no more than 0.3 mm long
                       Back to 30
33
32Nut less than half as long as glume; annual with thin-textured leaves and bracts, not septate-noduloseCyperus compressus
Nut at least half as long as glume; slender perennial with tough-textured leaves and bracts, often obviously septate-nodulose when dried
                       Back to 31
Cyperus clarus
33Nut yellow-brown, nearly as long as glume; glumes 2–3 mm long; leaves and bracts tough-textured, often obviously septate-nodulose when driedCyperus fulvus
Nut dark red-brown, less than half as long as glume; glumes 3–3.5 mm long; leaves and bracts thin-textured, not septate-nodulose
                       Back to 31
Cyperus rigens
34Leaves and bracts tough-textured, flat or folded, margins and midribs scabrous; lowest involucral bract suberect; rhizomatous perennial with solitary culmsCyperus lhotskyanus
Leaves and bracts thin-textured, flat or with revolute margins; lowest involucral bracts spreading; tufted perennial, often apparently annual and without a rhizome
                       Back to 30
Cyperus congestus
35Involucral bracts 6–22 exceeding inflorescence (rarely only as long as inflorescence)36
Involucral bracts 1–5 exceeding inflorescence
                       Back to 5
43
36Leaves all or mostly reduced to sheaths37
Leaves with well-developed blade
                       Back to 35
39
37Involucral bracts 12–22 exceeding inflorescence; glumes c. 2 mm longCyperus involucratus
Involucral bracts 6–9 exceeding or as long as inflorescence; glumes 1–2.5 mm long
                       Back to 36
38
38Glumes 2–2.5 mm longCyperus vaginatus
Glumes 1–1.3 mm long
                       Back to 37
Cyperus filipes
39Inflorescence with few (1–9, rarely to 15 in Cyperus vaginatus) spikelets per loose cluster40
Inflorescence with numerous spikelets per dense globose cluster
                       Back to 36
42
40Leaves with 2 prominent, whitish (at least when dried) lateral veins; glumes straw-coloured to pale brown, 1–1.5 mm long; rachilla winged; leaf sheaths purplish red at baseCyperus albostriatus
Leaves with only midvein prominent; glumes red-brown to blackish; rachilla not winged; leaf sheaths purplish red or pale yellow-brown at base
                       Back to 39
41
41Nut ellipsoid; leaf sheaths purplish red at base; glumes very dark red-brown to blackish, 1.5–2 mm longCyperus tetraphyllus
Nut ovoid; leaf sheaths pale yellow-brown at base; glumes red-brown, 3–3.5 mm long
                       Back to 40
Cyperus rupicola
42Inflorescence with numerous branches; culms 25–90 cm highCyperus eragrostis
Inflorescence head-like; culms 1–20 cm high
                       Back to 39
Cyperus pygmaeus
43Leaves all or mostly reduced to sheaths44
Leaves with well-developed blade
                       Back to 35
46
44Culms and involucral bracts firm to rigid; culms terete to trigonous45
Culms and involucral bracts soft-textured; culms triquetrous
                       Back to 43
Cyperus haspan
45Involucral bracts mostly 5–8 in number, always more than 5 cm and up to 15 cm long, flat, firm-textured, not pungent; inflorescence simple to compound with 4–12 branches to 6 cm long, bearing hemispherical clusters of spikelets, or occasionally loosely head-likeCyperus vaginatus
Involucral bracts 2–4, usually less than 5 cm long, very rigid and pungent with incurved margins; inflorescence head-like or with 1–3 short branches to 2 cm long, bearing globose clusters of spikelets
                       Back to 44
Cyperus gymnocaulos
46Nut trabeculate and striateCyperus mirus
Nut smooth or minutely roughened
                       Back to 43
47
47Glumes less than 2 mm long (excluding any long mucro)48
Glumes 2 mm or more long (excluding any long mucro)
                       Back to 46
69
48Glumes with sides evenly red-brown to dark red-brown or blackish (midribs mostly green)49
Glumes uniformly green or with sides hyaline, white, pale brown, yellow or golden brown, occasionally with a red-brown patch (midribs mostly green)
                       Back to 47
57
49Rachilla wingedCyperus rigidellus
Rachilla not winged
                       Back to 48
50
50Spikelets numerous in the dense globose clusters51
Spikelets few (1–12) in the loose, ovoid to hemispherical clusters
                       Back to 49
53
51Glumes 0.6–0.9 mm longCyperus difformis
Glumes at least 1.0 mm long
                       Back to 50
52
52Glumes 1.5–2 mm longCyperus reflexus
Glumes 1.0–1.4 mm long
                       Back to 51
Cyperus castaneus
53AnnualCyperus castaneus
Perennial
                       Back to 50
54
54Glumes red-brownCyperus haspan
Glumes dark red-brown to blackish
                       Back to 53
55
55Inflorescence compound; nut c. 0.5 mm long, less than half as long as glumeCyperus concinnus
Inflorescence simple; nut 1.3–1.5 mm long, nearly as long as glume
                       Back to 54
56
56Glumes acute, dorsally straight in side viewCyperus disjunctus
Glumes obtuse, shortly mucronate, dorsally strongly curved in side view
                       Back to 55
Cyperus tetraphyllus
57Inflorescence compound to decompound with numerous clusters of spikelets; glumes evenly yellow to golden brown; leaves strongly septate-nodulose, thick-textured; robust perennialCyperus dactylotes
Inflorescence simple with 1–8 clusters of spikelets; glumes not evenly yellow to golden brown (occasionally with yellowish patches); leaves not or rarely slightly septate-nodulose but then thin-textured; slender perennials or annuals
                       Back to 48
58
58Glumes with 2–5 nerves on each side59
Glumes with 1 nerve or no nerves on each side
                       Back to 57
63
59Involucral bract 1, erect; inflorescence of 1–4 spikelets; dwarf annualIsolepis levynsiana
Involucral bracts 2–4, erect to spreading; inflorescence with 1–25 spikelets; small perennials or annuals
                       Back to 58
60
60Spikelets 2.5–4 mm wide in side view; nut pale brownCyperus rigidellus
Spikelets 2–2.5 mm wide in side view; nut dark brown
                       Back to 59
61
61Glumes strongly excurved; inflorescence of 1–5 spikeletsCyperus sculptus
Glumes dorsally slightly incurved in side view to slightly excurved; inflorescence of 12–25 spikelets
                       Back to 60
62
62Nut broad-obpyriform to broad-obovoid, with globose bulge near base of persistent style baseCyperus enervis
Nut ellipsoid to broad-ellipsoid, without persistent dilated style base
                       Back to 61
Cyperus eglobosus
63Keel of glumes a broad band about as wide as thinner-textured side of glume64
Keel of glumes a narrow band, much narrower than sides of glume
                       Back to 58
67
64Tufted annuals; midrib of glumes with larger, more isodiametric cell outlines than on sides65
Perennials, shortly rhizomatous, often with fibrous remains of leaf sheaths at base; midrib and sides of glumes with similar cell outlines
                       Back to 63
66
65Spikelets 2–2.5 mm wide in side view; glumes 1–1.5 mm longCyperus flaccidus
Spikelets c. 3 mm wide in side view; glumes 1.5–2 mm long
                       Back to 64
Cyperus aquatilis
66Glumes c. 1.5 mm long, longer than broad; stamens 3Cyperus trinervis
Glumes 1–1.3 mm long, about as long as broad; stamens 2
                       Back to 64
Cyperus stradbrokensis
67Glumes strongly curved dorsally in side view, with excurved apex, 1.5–1.7 mm long, c. 0.5 mm wide in side view; inflorescence usually with 1–4 short branchesCyperus imbecillis
Glumes more or less straight dorsally from shortly above base in side view, 1.7–2 mm long, 0.7–1 mm wide in side view; inflorescence usually a single sessile cluster of spikelets (rarely with 1 or 2 very short branches)
                       Back to 63
68
68Involucral bract 1 longer than inflorescenceCyperus laevis
Involucral bracts 2–4 longer than inflorescence
                       Back to 67
Cyperus enervis
69Nut with paler corky, thickened anglesCyperus platystylis
Nut without corky, thickened angles
                       Back to 47
70
70Nut ovoidCyperus rupicola
Nut obovoid to ellipsoid
                       Back to 69
71
71Glumes with sides uniformly yellow to red-brown72
Glumes with sides uniformly green, whitish, pale brown, or with red-brown patch
                       Back to 70
85
72Glumes with midrib about as wide as sides and with cell outlines larger than on sides, 1-nerved only at edge of midribCyperus eragrostis
Glumes with midrib much narrower than sides and with cell outlines similar to those of sides, with 2–4 nerves on each side
                       Back to 71
73
73Leaves and bracts strongly curly at least near apex74
Leaves and bracts straight to slightly curved
                       Back to 72
77
74Anthers 1.3–1.6 mm long; glume mucro no more than 0.1 mm longCyperus secubans
Anthers 0.3–1.2 mm long; glume mucro 0.1–0.8 mm long
                       Back to 73
75
75Glumes evenly yellow to golden brown, with mucro 0.3–0.8 mm long (usually excurved); nut grey to blackCyperus clarus
Glumes straw-coloured to golden brown and with dull red-brown patches, with straight mucro 0.1–0.3 mm long; nut pale yellow-brown
                       Back to 74
76
76Leaf marginal prickles erect, papillose; leaf sheaths pinkish to purple-red; nut tuberculate or colliculateCyperus rigidellus
Leaf marginal prickles either mixed strongly flabellate to erect aculeate or antrorsely aculeate; leaf sheaths pale yellowish with red-brown blotches; nut colliculate to smooth and reticulate-areolate
                       Back to 75
Cyperus fulvus
77Nut red-brown to black or grey, tuberculate (occasionally smooth in Cyperus gilesii)78
Nut yellow-brown to dark golden brown, smooth to colliculate or pitted
                       Back to 73
80
78Anthers 1.1–1.8 mm long; nut narrow-ellipsoid to narrow-obovoid, red-brownCyperus alterniflorus
Anthers 0.3–0.8 mm long; nut very narrow-ellipsoid or obovoid, red-brown to blackish or grey to black
                       Back to 77
79
79Nut very narrow-ellipsoid, red-brown to blackish; glumes very narrow-elliptic to narrow-ovateCyperus gilesii
Nut obovoid, grey to black; glumes elliptic to ovate
                       Back to 78
Cyperus clarus
80Prickles on leaf margins antrorsely aculeate, more or less regularly spaced81
Prickles on leaf margins mixed aculeate to papillose, antrorse to erect and flabellate, more or less irregularly spaced
                       Back to 77
83
81Glumes dark red-brown or rarely straw-coloured; spikelet clusters dense; leaves exceeding or as long as culmsCyperus gunnii
Glumes yellow to dark golden brown; spikelet clusters loose; leaves shorter than to as long as culms
                       Back to 80
82
82Glumes 2.5–3.4 mm long; glume spacing 1.6–2.3 mmCyperus betchei
Glumes 1.3–2.1 mm long; glume spacing 0.9–1.3 mm
                       Back to 81
Cyperus dactylotes
83Anthers 0.3–1.2 mm longCyperus fulvus
Anthers 1.3–2.0 mm long
                       Back to 80
84
84Long-rhizomatous, with culms usually solitary along rhizome; leaves V-shaped in cross section, with midrib obvious abaxially, with marginal prickles irregularly spaced; plants never viscidCyperus lhotskyanus
Very shortly rhizomatous, with culms tufted; leaves canaliculate, with midrib not obvious, with marginal prickles regularly spaced; plants often viscid
                       Back to 83
Cyperus secubans
85Spikelets less than 2.5 mm wide in side view86
Spikelets 2.5–5 mm wide in side view
                       Back to 71
88
86Inflorescence a single cluster of 1–14 spikelets87
Inflorescence simple to compound, with 3–8 primary branches and numerous spikelets
                       Back to 85
Cyperus fulvus
87Glumes 3- or 4-nerved on each side; apex excurved in side viewCyperus gracilis
Glumes 1- or 2-nerved on each side; apex more or less straight in side view
                       Back to 86
Cyperus enervis
88Glumes with midrib about as wide as sides and with cell outlines larger than on sides, nerved only at edge of midribCyperus eragrostis
Glumes with midrib much narrower than sides and with cell outlines similar to those of sides, with 2–4 nerves on each side
                       Back to 85
89
89Nut dark brown to black, less than half as long as glume; leaves never curly; plant never viscidCyperus compressus
Nut pale yellow-brown, three-quarters to seven-eighths as long as glume; leaves often curly towards apex; plants occasionally viscid
                       Back to 88
90
90Culms 3–25 cm long; leaves not septate-nodulose; leaf sheaths pinkish to purple-red near baseCyperus rigidellus
Culms 25–50 cm long; leaves mostly septate-nodulose; leaf sheaths pale yellowish or straw-coloured with occasional red-brown patches
                       Back to 89
Cyperus fulvus
91Inflorescence of 1–6 sessile spikes, rarely with 1–3 short branches to 1.5 cm long92
Inflorescence simple or compound with spikes on 3–14 branches to 20 cm long (rarely head-like in Cyperus leiocaulon)
                       Back to 4
93
92Bases of culms bulbously swollen; glumes acute; flowers 1–3 per spikeletCyperus aggregatus
Bases of culms apparently enlarged for some distance because of persistent, whitish, thin-textured leaf sheaths; glumes obtuse; flowers 3–6 per spikelet
                       Back to 91
Cyperus dubius
93Culms and rachis of inflorescence hispid or papillose-scabrous94
Culms and rachis of inflorescence smooth
                       Back to 91
95
94Culms and rachis hispid-scabrous, green; leaves septate-noduloseCyperus scaber
Culms and rachis papillose-scabrous, greyish; leaves not septate-nodulose
                       Back to 93
Cyperus conicus
95Involucral bracts 7–13 exceeding inflorescence; leaves strongly septate-noduloseCyperus vorsteri
Involucral bracts 1–8 exceeding inflorescence; leaves not septate-nodulose
                       Back to 93
96
96Spikelets c. 0.5 mm diam.when mature97
Spikelets 0.7–1.5 mm diam. when mature
                       Back to 95
99
97Glumes 2.3–2.7 mm long; flowers 3–6; base of culms not enlarged98
Glumes 3–3.5 mm long; flowers 1–3; base of culms bulbously enlarged
                       Back to 96
Cyperus cyperoides
98Spikelets spreading at 90–140° from the vertical; culms rigid, erect, 2–4 mm diam.Cyperus dietrichiae
Spikelets spreading at 40–90° from the vertical; culms lax, c. 1 mm diam.
                       Back to 97
Cyperus bowmannii
99Spikelet falling as a unit; inflorescence simple100
Spikelet breaking up and dispersing as individual corky internodes of rachilla with associated glume and nut; inflorescence compound
                       Back to 96
Cyperus odoratus
100Involucral bracts 2 exceeding inflorescence; flowers 5–16 per spikeletCyperus subulatus
Involucral bracts 3–5 exceeding inflorescence; flowers 2–4 per spikelet
                       Back to 99
Cyperus leiocaulon
101Spikelets several- to numerous-flowered; rachilla continuous, persistent; glumes individually deciduous at maturity102
Spikelets 1-flowered, but sometimes with a second imperfect flower above, whole spikelet falling as a unit at maturity
                       Back to 1
109
102Inflorescence pseudolateral, sessile; lowest involucral bract erect, appearing as a continuation of the rush-like culmCyperus laevigatus
Inflorescence obviously terminal, branched or head-like; involucral bracts not as above
                       Back to 101
103
103Nut dorsally flattened with a flat or concave face against the rachilla; inflorescence densely head-like, subglobose, with 5–7 or more involucral bracts exceeding inflorescenceCyperus pygmaeus
Nut laterally flattened, with one edge against the rachilla; inflorescence loosely head-like or branched, with 1–4 involucral bracts exceeding inflorescence
                       Back to 102
104
104Glumes 3.5–4.5 mm long, acute; spikelets 3.5–5 mm wide in side viewCyperus unioloides
Glumes less than 3 mm long, obtuse (occasionally broad-acute in Cyperus polystachyos); spikelets 1–3 mm wide in side view
                       Back to 103
105
105Glumes with excurved mucro 0.3–0.7 mm long; glume-spacing c. 0.5 mmCyperus nervulosus
Glumes not mucronate or scarcely mucronulate; glume-spacing c. 1 mm
                       Back to 104
106
106Glumes incurved dorsally in side view, dark red-brown to blackish, often with a hyaline patch on sidesCyperus sanguinolentus
Glumes more or less straight dorsally in side view, yellow to very dark yellow-brown, occasionally red-brown in Cyperus polystachyos and C. flavidus but never with a hyaline patch
                       Back to 105
107
107Spikelets suberect, usually densely crowded in obconical subdigitate clusters; rachilla narrowly wingedCyperus polystachyos
Spikelets spreading widely, in loose, shortly spicate to subdigitate clusters; rachilla not winged
                       Back to 106
108
108Nut with faint whitish transverse wrinklesCyperus flavescens
Nut minutely puncticulate
                       Back to 107
Cyperus flavidus
109Tufted annual or perennial with or without a very short rhizome; inflorescence whitish or very light green; nut black at maturity; stamens 2Cyperus sesquiflorus
Perennial with creeping rhizomes, to 30 cm long but occasionally very short; inflorescence greenish or yellow-tinged; nut yellowish becoming brown at maturity
                       Back to 101
110
110Inflorescence more or less ovoid, dense, solitary or with 2 smaller ones at the base; spikelets numerous, sometimes 100 in number, 1-flowered; midrib of the glumes usually toothed; stamen 1 or 2 (rarely 3)Cyperus brevifolius
Inflorescence globose, loose, always solitary; spikelets not usually more than 50, a second imperfect flower often present; midrib of the glumes usually smooth or nearly so, rarely toothed; stamens (2 or) 3
                       Back to 109
Cyperus sphaeroideus

  Privacy | Copyright | Disclaimer | About PlantNET | Cite PlantNET