e-Key v3 - Key to Cyperaceae Genera
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Interactive keys to the identification of seed plants of southern Africa using keys based on plant morphology.
  • The following key attempts, as far as possible, to reflect the classification presented in L- 2000, but it must be appreciated that many of the important classificatory characters are of little use in a key, which is of necessity based on easily observed morphological characters
  • Additionally, because spikelet bracts often grade into glumes or are difficult to distinguish from one another, the following wording is used in the key in order to reduce confusion:
    • 'glumes and/or spikelet bracts'.
Backtrack a
  • Florets all bisexual, or bisexual and unisexual or functionally unisexual together
  • Spikelets, at least aerial ones, bisexual
  • Some empty glumes and/or spikelet bracts occasionally present
002
b
  • Florets all unisexual or functionally unisexual
  • Spikelets unisexual or bisexual
  • Some empty glumes and/or spikelet bracts present
Group 6 (041)
Backtrack a
  • Spikelets composed of (1-)several bisexual florets, or of bisexual and unisexual florets together, with several empty glumes and/or spikelet bracts at base
002
b
  • Spikelets composed of 1 bisexual floret, with 0-1 empty glumes and/or spikelet bracts at base
Group 1 (007)
Backtrack a
  • Glumes distichous
002
b
  • Glumes subdistichous to spirally arranged
002
Backtrack a
  • Spikelets with 0-2 empty glumes and/or bracts at base
  • Nutlets not accompanied by bristles
Group 2 (011)
b
  • Spikelets with 3 or more empty glumes and/or bracts at base
  • Nutlets sometimes accompanied by bristles
Group 4 (033)
Backtrack a
  • Spikelets with 0-2 empty glumes and/or bracts at base
002
b
  • Spikelets with 3 or more empty glumes and/or bracts at base
Group 5 (036)
Backtrack a
  • Stamens 6
Cyathocoma
b
  • Stamens 1-3
Group 3 (015)
Group 1
Spikelets composed of 1 bisexual floret
Backtrack a
  • Plants aquatic
  • Inflorescence diffuse, comprising many, mostly sterile compoundly whorled branches
  • Spikelets single on ends of fertile branches
Websteria
b
  • Plants terrestrial
  • Inflorescence capitate, digitate, or anthelate to compound-anthelate
002
Backtrack a
  • Glumes adaxially connate, dorsiventrally compressed or trumpet-shaped
Ascolepis
b
  • Glumes not adaxially connate
002
Backtrack a
  • Spikelet bracts smaller than spikelet
  • Glumes well developed
Alinula
b
  • Spikelet bracts much larger than spikelet
  • Glumes reduced, hyaline
002
Backtrack a
  • Culms at least 50(-450) mm high
  • Spikelets spirally arranged, prophyll hyaline
Lipocarpha
b
  • Culms 0 or very short
  • Spikelets subdistichous, prophyll thick-textured
Volkiella
Group 2
Spikelets composed of (1-)several bisexual florets; glumes distichous
Backtrack a
  • Stigmas 3 (sometimes very short or 0), or if 2, nutlet dorsiventrally compressed
002
b
  • Stigmas 2
  • Nutlet laterally compressed
002
Backtrack a
  • Perennials (occasionally annual) without fenugreek odour when dried
Cyperus
b
  • Annuals with fenugreek odour when dried
002
Backtrack a
  • Inflorescences squarrose
  • Keels of glumes not winged, excurrent into awn at least a quarter the length of glume body
Cyperus
subgen. Aristomariscus
b
  • Inflorescences not squarrose
  • Keels of glumes winged, hardly excurrent
Courtoisina
Backtrack a
  • Inflorescence digitate or anthelate to compound-anthelate
  • Florets many (more than 5)
Pycreus
b
  • Inflorescence capitate (occasionally with accessory capitula)
  • Florets 1 or 2(-5)
Kyllinga
Group 3
Spikelets composed of several to many bisexual florets; glumes subdistichous to spirally arranged; stamens 1-3
Backtrack a
  • Style base enlarged
002
b
  • Style base not enlarged
002
Backtrack a
  • Inflorescence a single spikelet (occasionally with accessory spikelets)
  • Inflorescence bracts scale-like
  • Style base persisting
Eleocharis
b
  • Inflorescence seldom a single spikelet, or if so, then inflorescence bracts not scale-like and style base not persisting
002
Backtrack a
  • Mouth of leaf sheath pilose
  • Style base persisting as a button-like structure on nutlet
Bulbostylis
b
  • Mouth of leaf sheath glabrous
  • Style base not persisting on nutlet
002
Backtrack a
  • Inflorescence of 1-4 large spikelets longer than 8 mm
  • Stigmas 3
  • Nutlet obpyriform, epidermal cells isodiametric
Abildgaardia
b
  • Inflorescence of more than 10 small spikelets shorter than 5 mm, or if longer than 8 mm, then stigmas 2
  • Nutlet obovoid (occasionally obpyriform), epidermal cells mostly horizontally elongated
Fimbristylis
Backtrack a
  • Nutlet borne on gynophore
002
b
  • Nutlet not borne on gynophore
002
Backtrack a
  • Ligule usually well developed, papyraceous
Ficinia
b
  • Ligule not well developed
002
Backtrack a
  • Plants annual
Isolepis marginata
b
  • Plants perennial
002
Backtrack a
  • Leaf blades well developed
  • Plants occurring in high-altitude grassland in summer-rainfall region
Scirpus falsus, S. ficinioides
b
  • Leaf blades reduced to sheaths (sometimes a very short blade developed)
  • Plants occurring along coast (occasionally inland) from KwaZulu-Natal to Northern Cape
Scirpoides ( Ficinia ) nodosus
Backtrack a
  • Culms nodose (i.e. nodes aerial, spaced ± equally along culm), leaf-bearing, usually markedly 3(-5)-angled
002
b
  • Culms appearing nodeless (i.e. nodes ± basal, concealed by leaves)
002
Backtrack a
  • Inflorescence anthelate to compound-anthelate, occasionally capitate or reduced to a single spikelet but, if so, with at least 2 leaf-like involucral bracts
Bolboschoenus
b
  • Inflorescence paniculate or occasionally capitate but, if so, with only 1 involucral bract
Fuirena
Backtrack a
  • Leaf blades well developed
002
b
  • Leaf blades reduced to sheaths (sometimes a very short blade developed)
002
Backtrack a
  • Floating aquatic plants
  • Inflorescence anthelate, ultimate units capitate
  • Nutlet long-beaked, with corky flotation tissue at base
Oxycaryum
b
  • Terrestrial plants, if aquatic then rooted in substrate and inflorescence a single spikelet or capitate/digitate
  • Nutlet beakless or shortly beaked without flotation tissue
002
Backtrack a
  • Inflorescence white, capitate, 5-7 mm in diameter
  • Involucral bracts (2)3
Kyllingiella
b
  • Inflorescence not as above
002
Backtrack a
  • Hard, perennial plants occurring in grassland or denuded areas
Scirpus
b
  • Soft, annual or perennial plants, if perennial then occurring in aquatic or marshland habitats
Isolepis
Backtrack a
  • Inflorescence pseudolateral with subtending bract appearing as continuation of culm
002
b
  • Inflorescence terminal
002
Backtrack a
  • Glumes generally mucronate or, if inflorescence digitate and glumes rounded, then inflorescence bract more than half (-3 () length of culm
Schoenoplectus
b
  • Glumes generally rounded at apex and inflorescence digitate or, if inflorescence of several stalked, rounded clusters of spikelets, and glumes mucronate, then inflorescence bract in both cases less than 1/40 length of culm
Scirpoides
Backtrack a
  • Inflorescence paniculate, of many spikelets
Pseudoschoenus
b
  • Inflorescence capitate, of (1-)several spikelets
002
Backtrack a
  • Dwarf annuals or slender perennials up to 200 mm tall (usually less)
  • Spikelets less than 3 mm in diameter
Isolepis
b
  • Densely tufted robust perennials 400-800 mm tall
  • Spikelets ± 7 mm in diameter
Hellmuthia
Group 4
Glumes distichous; spikelets with 3 or more empty glumes and/or bracts at base
Backtrack a
  • Spikelets with bristles
002
b
  • Spikelets without bristles, or if present, minute
002
Backtrack a
  • Spikelets of 2 kinds - > 0 subterranean female (without bristles) and aerial bisexual
  • Bristles 3, complex
Trianoptiles
b
  • Spikelets all aerial, bisexual
  • Bristles 6, simple
Carpha
Backtrack a
  • Rachilla of spikelet between bisexual florets elongated, thickened and curved
Schoenus
b
  • Rachilla of spikelet elongated and sometimes curved above uppermost bisexual floret
Epischoenus
Group 5
Glumes subdistichous to spirally arranged; spikelets with 3 or more empty glumes and/or bracts at base
Backtrack a
  • Stigmas 2
Rhynchospora
b
  • Stigmas 3 or more
002
Backtrack a
  • Leaves mostly reduced to sheaths, uppermost leaf lamina cylindrical and similar to culms
Neesenbeckia
b
  • Leaves not as above
002
Backtrack a
  • Nutlet long-clawed
002
b
  • Nutlet sessile or shortly clawed
002
Backtrack a
  • Inflorescence a large panicle of many spikelets
  • Glumes chestnut brown
Costularia
b
  • Inflorescence a reduced panicle of 6 (or fewer) spikelets
  • Glumes green to yellow-green, drying light brown
Capeobolus
Backtrack a
  • Large robust plants
  • Culm nodose, rounded and hollow
  • Inflorescence a panicle
Cladium
b
  • Plants variable in height and robustness
  • Culm variable, if nodose then triangular in cross section and solid
  • Inflorescence variable
Tetraria
Group 6
Spikelets bisexual or unisexual (or functionally unisexual); florets all unisexual
Backtrack a
  • Plants functionally dioecious, rush-like
  • Inflorescence capitate, pseudolateral (subtending bract appearing as a continuation of culm)
Scirpoides dioecus
b
  • Plants neither dioecious nor rush-like
002
Backtrack a
  • Spikelet solitary, pseudolateral, composed of many male florets and one terminal female floret
Chrysitrix
b
  • Spikelet not as above
002
Backtrack a
  • Female spikelet not enclosed by a perigynium (modified bract)
002
b
  • Female spikelet partially or wholly enclosed by perigynium
002
Backtrack a
  • Hard grass-like plants inhabiting rock outcrops
  • Leaf sheaths split to base, blades abscising at apex of sheath, ligule a hairy ring
  • Inflorescence a slender panicle
  • Nutlet with loosely attached pericarp resembling perigynium
  • Bristles present
Coleochloa
b
  • Not as above
002
Backtrack a
  • Bisexual, male and female spikelets clustered together
  • Nutlet borne on a stalk (gynophore)
Scleria
b
  • Male spikelets borne at upper nodes of inflorescence, female spikelets borne at lower nodes
  • Nutlet not borne on a stalk (gynophore)
Tetraria crinifolia
Backtrack a
  • Perigynium entire or split unevenly in one or two places
  • Rachilla present, usually bearing male florets, which are exserted from perigynium
Schoenoxiphium
b
  • Perigynium entire, bottle-shaped, frequently apex rostrate, 2-toothed
  • Rudimentary rachilla occasionally present within perigynium
Carex

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