Family Cyperaceae
Description: Perennial or annual herbs, often with a grass-like or rush-like habit, tufted or rhizomatous, sometimes stoloniferous, rarely tuber-producing. Culms (aerial stems) usually solid, rarely hollow between transverse septa, triquetrous to terete, occasionally 4- or 5-angular.
Leaves only at base of the culm or also cauline, the outer basal ones often reduced to ± open sheathing scales in continuance of those on the rhizome; inner leaves, as well as the cauline ones, embracing the culm with closed tubular sheaths; blade usually narrow and grass-like, occasionally reduced; ligule present (membranous or ciliate) or absent.
Inflorescence simple or compound, variously umbel-like, panicle-like or head-like, or reduced to a single spikelet; subtended by one or more leaf-like or occasionally glume-like or culm-like involucral bracts, lowest ones often much exceeding inflorescence and resembling the leaves, the others gradually smaller, upper ones (and sometimes all) small and glume-like. Spikelets either solitary or clustered, terete or compressed, 1–many-flowered; rachilla sometimes winged. Flowers small and inconspicuous, bisexual, or unisexual and monoecious or very rarely dioecious, each usually solitary within a bract called a glume. Glumes arranged either distichously or spirally on the rachilla of the spikelet, one or more of the lower or upper ones often empty. Perianth reduced to hypogynous scales, bristles or hairs, very rarely subpetaloid or disk-like, often absent. Stamens 3 or fewer, very rarely more; filaments free; anthers basifixed, oblong or linear,2-locular, dehiscing by longitudinal slits, the connective often produced in a small apical appendage, glabrous or hispidulous. Ovary superior, 1-locular with one erect ovule; style terminal, filiform or variously thickened at the base, ± deeply divided into 2 or 3 (rarely more) branches, rarely simple.
Fruit a small seed-like nut, that from a 2-lobed style usually ± 2-sided and that from a 3-lobed style ± 3-angular or terete.
Distribution and occurrence: World: c. 90 gen., c. 5,400 spp;, cosmopolitan, mostly in damp or swampy places. Aust.: c. 45 gen., c. 900 spp., all States. The genus Carex is one of the largest genera in the plant world, with about 2,200 species.
External links:
Angiosperm Phylogeny Website (Family: Cyperaceae, Order: Poales)
Wikipedia Most members of the family are of key ecological importance in a wide range of habitats globally. However, there are few species of economic importance in the commonly accepted sense. The tubers of some species of Cyperus and Eleocharis contain starch and have been used as food (e.g. Water chestnut, Eleocharis dulcis). The paper of the ancient Egyptians was manufactured from Papyrus (Cyperus papyrus L.). Some species are used regionally in the fabrication of mats, brooms, etc. A few have ornamental or medicinal purposes. Note: leaves are described as septate-nodulose when they contain numerous small transverse septa that are obvious at least when dried. Culm diameter and leaf breadth are measured about halfway along the organ. Culm length is measured from the base of the plant to the lowest involucral bract at base of inflorescence (in some cases, the inflorescence is very much longer than the true culm). Inflorescence length, where given, does not include any longer involucral bracts. Anther length measurements do not include any apical appendage because the appendages are fragile and break off readily. The inflorescence in most members of the Cyperaceae has been called an anthela, but that name is technically inappropriate (see Wilson (1991) p. 367). The basic funnel-shaped structure, with spikelets on branches of different lengths is variously modified so that it appears umbel-like, panicle-like or even head-like to the casual glance. The inflorescence is here described as simple if there is only 1 order of branching present, compound if more. The spikelets are mostly easily recognizable units, with several–many modified bracts (glumes) each subtending a bisexual or unisexual flower or occasionally some empty at apex or base of spikelet. Generally, a rather leaf-like bract and a 2-keeled modified bract (prophyll) are present at the junction of the spikelet and inflorescence branch. In Carex, this arrangement is modified in female spikelets by the prophyll forming a fused 'flask' (utricle) around the 1-flowered spikelet. In subfamily Mapanioideae (here represented by Exocarya, Lepironia and Chorizandra), the floral arrangement is more complex and poorly understood. The basic floral unit in Exocarya and Lepironia consists of one broad, thick-textured, non-keeled, basal glume subtending 2 slender, thin-textured, lateral keeled glumes (with ciliolate keel) at each end of a 1 distichous, flattened array of 2–numerous slender, thin-textured, non-keeled glumes. The uppermost of these slender non-keeled glumes usually subtends a gynoecium, the rest with a single stamen or some empty. In Chorizandra, the floral unit differs in having a continuum of glume-form from the broader, mostly keeled (but not ciliolate) lowest 1–3 glumes to the narrow upper glumes. Also, the glumes are all spirally arranged, producing a terete unit. This floral unit is here termed a pseudospikelet since it may not be homologous with spikelets in the rest of the family. All floral scales are here called glumes. The pseudospikelets are clustered variously to form a spikelet-like (Lepironia) or head-like (Chorizandra) inflorescence or in spikelet-like units further clustered in compound umbel-like inflorescences (Exocarya). **Trachystylis stradbrokensis (Domin) Kuek. occurs in SE Qld and may occur in coastal northeastern N.S.W.
Text by K. L. Wilson (1993; edited Aug 2013, June 2020) Taxon concept:
Taxa not yet included in identification key
Lipocarpha
| Key to the genera | |
1 | Spikelets with several–many flowers producing nuts, usually only 1 or 2 lowest glumes empty | 2 |
| Spikelets or pseudospikelets with 1 or 2 (3) flowers producing nuts, usually several–many empty glumes at the base of the spikelet or pseudospikelet | 19 |
2 | Stems noded and leafy (also occasionally noded in aquatic species such as Isolepis fluitans, but then not large perennials, and bristles absent); hypogynous bristles or scales present | 3 |
| Culms not noded; leaves all basal; hypogynous bristles or scales present or absent Back to 1 | 5 |
3 | Three hypogynous scales inflated and more or less petaloid; 3 hair-like bristles also present; glumes with a long mucro about as long as glume | Fuirena |
| All hypogynous bristles hair-like; glumes with a mucro no more than half glume length Back to 2 | 4 |
4 | Spikelets less than 1 cm long; inflorescence branches scabrous; hypogynous bristles much longer than nut | Scirpus |
| Spikelets 1–2.5 cm long; inflorescence branches not scabrous; hypogynous bristles shorter than or equalling nut Back to 3 | Bolboschoenus |
5 | Style base enlarged and persistent on nut | 6 |
| Style base enlarged or not, but not persistent on nut Back to 2 | 7 |
6 | Inflorescence not subtended by leafy bracts; leaves reduced to sheaths, glabrous; hypogynous bristles usually present | Eleocharis |
| Inflorescence subtended by leafy bracts; leaves with well-developed blade, hairy near mouth of sheath; hypogynous bristles always absent Back to 5 | Bulbostylis |
7 | Hypogynous bristles present | Schoenoplectus |
| Hypogynous bristles absent Back to 5 | 8 |
8 | Style base enlarged but not persistent | 9 |
| Style base not enlarged or persistent Back to 7 | 10 |
9 | Glumes spirally arranged and spikelets terete, or rarely distichous and spikelets compressed (but then inflorescence with numerous spikelets) | Fimbristylis |
| Glumes distichous or upper part of spikelet twisted so as to be more or less spiral; spikelets compressed; inflorescence of 1–6 spikelets Back to 8 | Abildgaardia |
10 | Style 2-fid | 11 |
| Style 3-fid Back to 8 | 15 |
11 | Glumes distichously arranged in spikelet. (Subgenus 4 Pycreus) | Cyperus |
| Glumes spirally arranged in spikelet Back to 10 | 12 |
12 | Involucral bracts glume-like or leaf-like, from shorter than inflorescence to twice as long as it (to 1.5 cm long); spikelets 2–8 mm long | Isolepis |
| Involucral bracts culm-like, usually at least 4 times as long as inflorescence (to 25 cm long); spikelets 5–15 mm long Back to 11 | 13 |
13 | Nutlet epidermal cells narrow and longitudinally elongated or oblong, with straight or slightly undulate anticlinal walls; nutlet surface smooth or transversely rugose; basal flowers sometimes present | Schoenoplectiella |
| Nutlet epidermal cells usually hexagonal or isodiametric in shape and with straight or slightly undulate anticlinal walls, or oblong and with heavily waving anticlinal walls; nutlet surface smooth; basal flowers absent Back to 12 | Schoenoplectus |
14 | Rachilla internodes thickened and clasping nut at maturity. (Subgenus 3 Torulinium) | Cyperus |
| Rachilla neither thickened nor clasping nut Back to | 15 |
15 | Glumes distichously arranged in spikelet (spiral in Cyperus hamulosus but then plant has smell of fenugreek). (Subgenus 1 Anosporum, Subgenus 2 Cyperus) | Cyperus |
| Glumes spirally arranged in spikelet, not smelling of fenugreek Back to 14 | 16 |
16 | Nuts transversely wrinkled and/or stout perennials | 17 |
| Nuts variously marked but never transversely wrinkled; small annuals or perennials Back to 15 | 18 |
17 | Nutlet epidermal cells narrow and longitudinally elongated or oblong, with straight or slightly undulate anticlinal walls; nutlet surface smooth or transversely rugose; basal flowers sometimes present | Schoenoplectiella |
| Nutlet epidermal cells usually hexagonal or isodiametric in shape and with straight or slightly undulate anticlinal walls, or oblong and with heavily waving anticlinal walls; nutlet surface smooth; basal flowers absent Back to 16 | Schoenoplectus |
18 | Perennial with long-creeping, thick, woody rhizome to 1 cm diam.; minute hypogynous disc under nut | Ficinia |
| Plants in small tufts or with filiform rhizome; no disc under nut Back to 16 | Isolepis |
19 | Female flowers enclosed in sac-like utricle | 20 |
| Flowers not enclosed in a utricle Back to 1 | 21 |
20 | Slender rachilla inside utricle with a stiff exserted hooked tip; inflorescence always a single spike (formerly genus Uncinia) | Carex |
| No slender hooked rachilla inside the utricle; inflorescence of (1–) several–many spikes Back to 19 | Carex |
21 | Female flowers apparently terminal, always only 1 per pseudospikelet (floral unit) | 22 |
| Female or bisexual flowers lateral and axillary, one to many in a spikelet Back to 19 | 24 |
22 | Leaves flat, leafy, usually present along the culms as well as at the base; involucral bracts flat, leafy; nut much longer than glumes | Exocarya |
| Leaves terete or reduced to sheaths, at base of culm only; involucral bracts terete but often broad and flattened at the base; nut shorter than to equalling glumes Back to 21 | 23 |
23 | Nut biconvex; style 2-fid; inflorescence spike-like; nut finely striate longitudinally but not ribbed | Lepironia |
| Nut terete to obtusely trigonous, obovoid to globose; style (2- to) 3- or 4-fid; inflorescence globose, hemispherical, or ovoid; nut strongly ribbed longitudinally Back to 22 | Chorizandra |
24 | A hypogynous disk or 1 or 2 hyaline scales or 2–6 hypogynous bristles or scales present at base of nut (not always falling with nut) | 25 |
| Hypogynous bristles, scales and disk absent Back to 21 | 39 |
25 | Nut more or less enclosed in 2, or occasionally 1, hyaline scales. (Sect. Lipocarpha) | Cyperus |
| Nut without hyaline scales Back to 24 | 26 |
26 | Style simple or 2-fid | 27 |
| Style 3–8-fid Back to 25 | 28 |
27 | Style base differentiated, enlarged, and persistent; leaves without a ligule | Rhynchospora |
| Style base not differentiated or enlarged or persistent; leaves with a membranous ligule Back to 26 | Cyathochaeta |
28 | Hypogynous disk present at base of nut | 29 |
| Hypogynous bristles or scales present at base of nut Back to 26 | 30 |
29 | Glumes spirally arranged; most flowers bisexual; nut brownish, tough | Cladium |
| Glumes distichous; flowers unisexual; nut with white to purplish, fragile pericarp Back to 28 | Scleria |
30 | Upper internodes of rachilla prominently zigzag | Schoenus |
| Upper internodes of rachilla straight Back to 28 | 31 |
31 | Style base persistent, often enlarged in fruit | 32 |
| Style base deciduous Back to 30 | 36 |
32 | Inflorescence head-like | 33 |
| Inflorescence panicle-like, umbel-like, or spike-like Back to 31 | 34 |
33 | Ligule membranous, glabrous; inflorescence obconical or fan-shaped; leaf sheaths glabrous | Ptilothrix |
| Ligule membranous and ciliate; inflorescence globose; leaf sheaths long-ciliate on upper margins Back to 32 | Gymnoschoenus |
34 | Bristles 6, as long as, or longer than, the nut | Carpha |
| Bristles 2 to 5, much shorter than the nut Back to 32 | 35 |
34 | Glumes spirally arranged in the spikelet; hypogynous scales inflated or thickened | Lepidosperma |
| Glumes more or less distichously or spiro-distichously arranged in the spikelet; hypogynous scales flat, not thickened Back to 32 | 35 |
35 | Robust perennials with inflorescence c. 40 cm long. (Gahnia erythrocarpa) | Gahnia |
| Slender perennials with inflorescences 1–4[–30] cm long Back to 34 | Netrostylis |
35 | Hypogynous scales falling with the nut; leaf without pseudopetiole | 36 |
| Hypogynous scales persistent on rachilla after nut falls; leaf with pseudopetiole Back to 34 | Oreobolus |
36 | Inflorescence condensed-compound and appearing head-like; rhizomes pseudobulbous | Chaetospora |
| Inflorescence open or, if reduced, not head-like; rhizomes not psuedobulbous Back to 35 | 37 |
37 | Spikelets usually in clusters of 3, at 5–9 nodes; upper flower fertile; hypogynous scales 1/3–2/3 length of nut | Anthelepis |
| Spikelets usually solitary, or 2 or 3 in a terminal cluster; upper flower reduced and sterile; hypogynous scales <1/5 length of nut Back to 36 | Tricostularia |
39 | Style simple or 2-fid | 40 |
| Style 3–8-fid Back to 24 | 43 |
40 | Style base enlarged, persistent; ligule absent | Rhynchospora |
| Style base enlarged or not, but not persistent Back to 39 | 41 |
41 | Inflorescence umbel-like; ciliate ligule present | Trachystylis |
| Inflorescence of 1 to 3 dense, clustered heads; ligule absent Back to 40 | 42 |
42 | Hyaline scales usually 2 enclosing nut, occasionally 1 or absent; apparent glumes (= spikelet bracts) flat with 0–2 nerves on each side of midrib; nut dorsiventrally compressed, trigonous or plano-convex. (Sect. Lipocarpha) | Cyperus |
| Hyaline scales absent; glumes keeled, with 2–5 nerves on each side of midrib; nut laterally compressed (i.e. with an edge next to rachilla), biconvex. (Subgenus 5 Kyllinga) Back to 41 | Cyperus |
43 | Upper internodes of rachilla zigzag | Schoenus |
| Upper internodes of rachilla straight Back to 39 | 44 |
44 | Annual; inflorescence of 1 to 3 clustered heads with numerous spikelets. (Sect. Lipocarpha) | Cyperus |
| Perennials; inflorescence panicle-like, spike-like, or occasionally reduced to a few clustered spikelets Back to 43 | 45 |
45 | Leaves reduced to blade no more than 1 cm long | 46 |
| Leaves with well-developed blade to 1 m long Back to 44 | 48 |
46 | Persistent style base not separated from body of nut by a constriction | Machaerina |
| Persistent style base separated from body of nut by a constriction Back to 45 | 47 |
47 | Leaves without a ligule | Caustis |
| Leaves with a ligule Back to 46 | Netrostylis |
48 | Leaves 2-ranked, isobilateral | Machaerina |
| Leaves 3-ranked, dorsiventral Back to 45 | 49 |
49 | Nut borne on inconspicuous hypogynous disk (disk may stay on rachilla rather than fall with nut) | Cladium |
| Nut not borne on a hypogynous disk Back to 48 | 50 |
50 | Spikelets disarticulating as a unit from axis at maturity. (Subgenus 2 Cyperus) | Cyperus |
| Spikelets persistent, nuts falling separately from glumes at maturity Back to 49 | 51 |
51 | Leaves with a ligule | Gahnia |
| Leaves without a ligule Back to 50 | Netrostylis |
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