Cyperaceae A. L. de Jussieu
Sedge family.
Cyperaceae, sedge family.
Vegetative morphology. Plants perennial herbs; caespitose, or not caespitose; grass-like, or rush-like with solid, often triangular stems cespitose, loosely tufted or matted. Taproot absent. Roots colourless, or yellow (tomentose), or pallid-brown, or red-brown, or black. Ground-level or under-ground stems horizontal, or not developed horizontally or vertically; rhizomatous, or stoloniferous; elongate, or compact. Scales present, or absent. Aerial stems erect, or decumbent; filiform, or not filiform; triangular in cross-section, or circular or oval in cross-section; glabrous, or sparsely hairy, or scabrous. Leaves in a basal tuft, or distributed along the stems; existing for a single season or less. Petioles absent. Sheaths persisting, or breaking down into fibres; forming a conspicuous build up at the base of the plant, or not forming a conspicuous build up at the base of the plant; greyish brown, or brown, or green, or reddish; with the margins fused to the apex; glabrous; collars absent. Ligules present; membranous; glabrous; ovate-oblong, or transversely oblong; apices acute, or obtuse; entire. Blades appressed to the stem, or spreading; herbaceous; straight, or somewhat curled; linear; circular in cross section, or triangular in cross section, or flat, or bristle-like, or strongly keeled, or involute, or revolute, or folded, or caniculate; veins parallel; midvein conspicuously larger than the lateral veins, or midvein similar in size to other veins in the leaf; septate nodulose, or not septate nodulose. Blades adaxial surface dull; glabrous. Blade margins entire; scabrous, or glabrous. Leaf apices acuminate.
Reproductive morphology. Plants monoecious, or dioecious, or bisexual. Flowering stems present. Flowering stems shorter than the leaves, or about as high as the leaves, or conspicuously taller than the leaves; with leaves, or without leaves, or without leaves in the upper half; uppermost leaf arising below the middle of the stem, or arising above the middle of the stem; glabrous. Flowering culm nodes not exposed. Leaf or reduced bract closely associated with the base of the inflorescence present, or absent; conspicuous and leaf-like, or reduced, or scale-like; exceeding the inflorescence, or similar in length to the inflorescence, or shorter than the apex of the inflorescence; with sheath longer than the blade, or with sheath shorter than the blade, or sheathless; persistent. Inflorescence spicate, or head-like; dense; linear, or oblong, or lanceolate, or ovate, or globose or subglobose, or obovate. Pedicels present (term used to describe branches at the top of the flowering stem that subtend individual groups of flowers (spikes)); glabrous, or scabrous. Inflorescence a single spike, or multispicate; lateral spikes sessile, or lateral spikes borne on pedicels. Individual spike(s) erect, or ascending, or divergent, or pendent. Bisexual spike(s) with empty bracts at the base, or without empty bracts at the base. Terminal spike staminate at the base, or wholly staminate, or staminate at the apex, or with both sexes in each floret, or pistillate. Cladoprophyll present at the base of the peduncle of lateral spikes, or absent. Flowers small, less than 5 mm in diameter or length; actinomorphic. Staminate flowers inconspicuous, or conspicuous. Floral scales shorter than the perigynium in fruit, or as long as the perigynium in fruit, or longer than the perigynium in fruit; brown, or black, or orange brown, or green, or pale grey; with margins the same colour as the body of the scale, or with margins, and sometimes midvein paler in colour than the adjacent area of the scale, or with margins darker in colour than the midvein, or with margins paler than body of scale; reflexed, or not reflexed; obtuse, or cuspidate, or acute; falling early, or not falling early; glabrous, or hairy all over. Floral bracts ovate, or lanceolate, or obovate. Perianth absent, or represented by bristles; bristles silky white, or translucent, or dull white or yellowish, or inconspicuous. Flowers unisexual, or bisexual. Stamens 3. Carpels syncarpous. Styles base an enlarged bulge, separated from the top of the achene, or base not enlarged, continuous with the achene (Eleocharis); thick and short, or slender, not extending beyond the beak, or slender, extending beyond the beak, or long and thick. Placentation basal. Fruit surrounded by a perigynium, or not surrounded by a perigynium. Perigynia open on one side, or with a slit running down the beak on the abaxial side through which the style protrudes, or fused to the apex except for a small aperture through which the style protrudes; globose, or subglobose, or lanceolate, or broadly ovate, or obovate, or elliptic; contracted at the base into a stipe-like structure, or sessile; erect or ascending, or reflexed, or spreading at maturity; black, or straw-coloured, or golden brown, or brown, or green, or whitish; membranous; surface glossy, or surface dull; glabrous, or hairy, or scabrous; tuberculate, or papillose; strongly nerved, or faintly nerved, or appearing nerveless; inflated, or not inflated; not keeled, or with 2 keels, or with 3 keels; apices beaked with a long beak, or beaked with a short beak, or merely conical or rounded; apex oblique, becoming slightly bidentate, or deeply bidentate, or not bidentate or oblique. Fruit an achene.
Cite this publication as: ‘S.G. Aiken, M.J. Dallwitz, L.L. Consaul, C.L. McJannet, L.J. Gillespie, R.L. Boles, G.W. Argus, J.M. Gillett, P.J. Scott, R. Elven, M.C. LeBlanc, A.K. Brysting and H. Solstad. 1999 onwards. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 29th April 2003. http://www.mun.ca/biology/delta/arcticf/’. Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993, 1995, 2000) should also be cited (see References).