Family Cyperaceae
Cyperaceae Juss.Including Kobresiaceae Gilly, Lepistichaceae Dulac, Scirpaceae Burnett Habit and leaf form. Herbs. ‘Normal’ plants, or switch-plants (sometimes elaminate); sometimes with the principal photosynthesizing function transferred to stems. Annual, or biennial, or perennial; with a basal aggregation of leaves (usually), or with neither basal nor terminal aggregations of leaves. Young stems not breaking easily at the nodes. (0.005–)0.05–3(–5) m high; rhizomatous, or tuberous. Hydrophytic, or helophytic, or mesophytic, or xerophytic (rarely, e.g. Caustis); when hydrophytic, free floating, or rooted. Leaves of aquatics submerged and emergent. Leaves alternate; spiral (rarely), or distichous (often), or tristichous (usually); flat, or folded (and occasionally plicate), or rolled, or terete; ‘herbaceous’, or leathery; sessile, or petiolate (occasionally); sheathing. Leaf sheaths with joined margins (usually), or with free margins. Leaves simple. Lamina entire; setaceous, or acicular, or linear to obovate; parallel-veined; cross-venulate, or without cross-venules. Leaves ligulate (commonly), or eligulate. Lamina margins usually entire (but commonly with prickle hairs); flat, or revolute, or involute. Prophylls 1. Leaves with a persistent basal meristem, and basipetal development. Vernation conduplicate, or plicate, or involute, or revolute, or convolute. General anatomy. Plants with silica bodies (usually). Chlorenchyma including ‘peg cells’ (if ‘lobed cells’ (Metcalfe 1971) be so interpreted), or without ‘peg cells’ (if not). Accumulated starch exclusively ‘pteridophyte type’. Leaf anatomy. Epidermis without differentiation into ‘long’ and ‘short’ cells; containing silica bodies (usually), or without silica bodies. Stomata present; usually paracytic. Lamina dorsiventral, or isobilateral, or centric. The mesophyll not containing mucilage cells; without calcium oxalate crystals (or very rare(?), and raphides absent). Minor leaf veins without phloem transfer cells (Cyperus, Eriophorum, Eleocharis). Vessels present; end-walls scalariform, or simple, or scalariform and simple. Stem anatomy. Stems with solid internodes to with spongy internodes, or with hollow internodes (uncommonly). Young stems triangular in section (commonly), or cylindrical, or oval in section, or flattened. Cork cambium absent. Secondary thickening absent (with compound vascular bundles in Gahnia). Xylem with vessels. Vessel end-walls scalariform, or simple, or scalariform and simple. Sieve-tube plastids P-type; type II. Root anatomy. Root xylem with vessels; vessel end-walls scalariform, or simple, or scalariform and simple. Reproductive type, pollination. Plants hermaphrodite, or monoecious, or andromonoecious, or gynomonoecious, or dioecious, or androdioecious, or gynodioecious. Floral nectaries absent (nectaries lacking). Pollination anemophilous (mostly), or entomophilous (occasionally, associated with white or coloured bracts or upper leaves). Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in ‘spikelets’. The ultimate inflorescence unit cymose, or racemose (the flowers solitary, or 1–50 in ‘spikelets’). Inflorescences with the spikelets often numerous, in branched, paniculate inflorescences. Flowers bracteate, or ebracteate; bracteolate (each borne in the axil of a ‘glume’); usually small, or minute. Perigone tube absent. Hypogynous disk absent (usually), or present (in a few genera). Perianth of ‘tepals’, or vestigial (represented by bristles or hairs), or absent; when present, often 6; free; sometimes more or less sepaloid. Androecium 1–3, or 4–6(–22). Androecial members free of the perianth; free of one another (usually), or coherent (connate filaments in some Carex species). Androecium exclusively of fertile stamens. Stamens 1–3, or 4–6(–22). Anthers basifixed; introrse, or latrorse; tetrasporangiate; appendaged (via prolongation of the connective into an apiculus), or unappendaged. Endothecium developing fibrous thickenings. The endothecial thickenings spiral (consistently so in a sample of 30 genera, Bruhl 1990). Anther epidermis persistent. Microsporogenesis simultaneous (specialised, ‘cyperaceous type’). The initial microspore tetrads undergoing degeneration, resulting in a pseudomonad. Anther wall initially with one middle layer; of the ‘monocot’ type. Tapetum glandular. Pollen shed in aggregates (though ostensibly solitary, as pseudomonads); in tetrads (with three members degenerated). Pollen grains aperturate; 1–4(–15) aperturate; ulcerate, or porate, or ulcerate and porate, or foraminate (usually with a single ulcoid aperture, but often with a ring of transverse lateral lacunae, rarely with four ill-defined foramina). The ulcus when ulcerate, without an operculum; without an annulus. Interapertural interstitium columellate. Pollen grains 2-celled (Fimbristylis, Scirpus), or 3-celled (Carex, Cyperus, Eleocharis, Rhynchospora, Schoenoplectus). Gynoecium 2 carpelled, or 3(–4) carpelled. The pistil 1 celled. Gynoecium syncarpous; synovarious to synstylovarious; superior. Ovary 1 locular. Styles 2–3; free to partially joined. Stigmas (1–)2, or 3(–15); dry type; papillate, or non-papillate; Group II type (IIA and IIB). Placentation basal. Ovules in the single cavity 1; non-arillate; anatropous; bitegmic; crassinucellate. Outer integument not contributing to the micropyle. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 3; not proliferating; ephemeral. Synergids hooked. Hypostase present, or absent. Endosperm formation nuclear. Embryogeny onagrad. Fruit non-fleshy; indehiscent; achene-like, or a drupe (very rarely). The drupes with one stone. Fruit 1 seeded. Seeds endospermic. Endosperm not oily (mealy or fleshy, usually), or oily (rarely). Seeds usually with starch. Embryo well differentiated, or rudimentary at the time of seed release (Rhynchosporoideae). Cotyledons when detectable, 1. Embryo achlorophyllous (doubtfully — 2/2). Testa without phytomelan. Seedling. Hypocotyl internode absent. Mesocotyl present (e.g. Isolepis), or absent. Seedling collar not conspicuous. Cotyledon hyperphyll compact; non-assimilatory. Coleoptile present. Seedling cataphylls absent. First leaf dorsiventral. Primary root ephemeral. Physiology, biochemistry. Not cyanogenic. Alkaloids present (occasionally, simple indole), or absent. Proanthocyanidins present (more commonly, and more abundantly, than in Gramineae), or absent; when present, cyanidin (usually), or cyanidin and delphinidin (Isolepis). Flavonols present (more commonly than in Gramineae), or absent; quercetin. Ellagic acid absent. Saponins/sapogenins absent. Aluminium accumulation demonstrated. C3 and C4, or C3-C4 intermediate. C3 physiology recorded directly in 103 genera: see Bruhl database. C4 physiology recorded directly in 27 genera: see Bruhl database. C3-C4 intermediacy in Eleocharis spp. Anatomy C4 type (27 genera), or non-C4 type (103 genera). Geography, cytology. Holarctic, Paleotropical, Neotropical, Cape, Australian, and Antarctic. Frigid zone to tropical. Cosmopolitan, predominating in moist habitats. Chromosomes with diffuse centromeres. Taxonomy. Subclass Monocotyledonae. Dahlgren et al. Superorder Commeliniflorae; Cyperales. APG 3 core angiosperms; Superorder Lilianae; commelinid Monocot; Order Poales. Species about 5400. Genera about 110; Abildgaardia, Acriulus, Actinoschoenus, Afrotrilepis, Alinula, Androtrichum, Anosporum, Arthrostylis, Ascolepis, Ascopholis, Baeothryon, Baumea, Becquerelia, Bisboeckelera, Blysmopsis, Blysmus, Bolboschoenus, Bulbostylis, Calyptrocarya, Capitularina, Carex, Carpha, Caustis, Cephalocarpus, Chorizandra, Chrysitrix, Cladium, Coleochloa, Costularia, Courtoisina, Crosslandia, Cyathochaeta, Cyathocoma, Cymophyllus, Cyperus, Desmoschoenus, Didymiandrum, Diplacrum, Diplasia, Dulichium, Egleria, Eleocharis, Eleogiton, Epischoenus, Eriophoropsis, Eriophorum, Erioscirpus, Evandra, Everardia, Exocarya, Exochogyne, Ficinia, Fimbristylis, Fuirena, Gahnia, Gymnoschoenus, Hellmuthia, Hemicarpha, Hymenochaeta, Hypolytrum, Isolepis, Kobresia, Kyllinga, Kyllingiella, Lagenocarpus, Lepidosperma, Lepironia, Lipocarpha, Lophoschoenus, Machaerina, Mapania, Mapaniopsis, Mariscus, Mesomelaena, Microdracoides, Micropapyrus, Monandrus, Morelotia, Neesenbeckia, Nemum, Nelmesia, Oreobolopsis, Oreobolus, Oxycaryum, Paramapania, Phylloscirpus, Pleurostachys, Principina, Pseudoschoenus, Ptilanthelium, Pycreus, Queenslandiella, Reedia, Remirea, Rhynchocladium, Rhynchospora, Rikliella, Schoenoplectus, Schoenoxiphium, Schoenoides, Schoenus, Scirpodendron, Scirpoides, Scirpus, Scleria, Sphaerocyperus, Sumatroscirpus, Syntrinema, Tetraria, Tetrariopsis, Thoracostachyum, Torulinium, Trachystylis, Trianoptiles, Trichoschoenus, Tricostularia, Trilepis, Tylocarya, Uncinia, Vesicarex, Volkiella, Websteria. Recent family treatments: Goetghebeur (1986); Bruhl (1995). For interactive identification and information retrieval, and comprehensive html generic descriptions, see J.J. Bruhl (1998), ‘Genera of Cyperaceae’, available online at HTTP://biodiversity.uno.edu/delta/caes/. Economic uses, etc. Some noxious weeds, otherwise of little economic importance — Cyperus papyrus is of historical interest in connection with papermaking, and that genus furnishes a few watergarden ornamentals; Cyperus esculentus has edible rhizomes. Illustrations. Quotations The gentle Severn’s sedgy bank You nymphs, called naiads, of the winding brooks, Nut-grass is not Grass |
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