Cyperaceae Juss.

Gemma Bramley, Anna Trias-Blasi & Richard Wilford (2023). The Kew Temperate Plant Families Identification Handbook. Kew Publishing Royal Botanic Gardens, Kew

Recognition

Characters of similar families: Juncaceae: stems rounded, flowers mostly hermaphrodite, minute and regular, perianth of 6 tepals, fruit a capsule with 3–many seeds. Poaceae: culms rounded or flattened and always hollow and noded, leaves 2-ranked, lemma and palea present in floret, fruit a caryopsis. Restionaceae: plants mostly dioecious, leaves usually reduced to sheaths, flowers mostly unisexual, minute and regular, perianth of 6 tepals, fruit a 1–3-locular capsule or nutlet.

Morphology General Habit

Herbs, rhizomatous to stoloniferous, or annual-Culms mostly 3-sided, solid, rarely noded

Morphology Leaves

Leaves, mostly 3-ranked toward base of culm, usually linear, grass-like, sometimes broader with a pseudopetiole, sometimes reduced to a sheath; ligule often present

Morphology Reproductive morphology Inflorescences Bracts Involucre

Involucral bracts 1–several, leaf-like or glume-like

Morphology Reproductive morphology Inflorescences

Inflorescence terminal, sometimes pseudolateral, simple or branched, umbel-like or paniculate, with 1–many partial inflorescence units (spikelets or spicoids)

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets comprising 1–many, spiral or 2-ranked glumes, each subtending 1 minute flower or sterile; spicoids comprising a female flower, 2–12 scale-like bracts, the outermost 2 bracts opposite and keeled, the spicoid subtended and usually hidden by a glume-like bract

Morphology Reproductive morphology Flowers Perianth

Perianth absent or bristle- or scale-like

Morphology Reproductive morphology Flowers Gynoecium Stigma

Stigmas 2–3

Morphology Reproductive morphology Fruits

Fruit a hard, 1-seeded, 2–3-sided nutlet, smooth or patterned, sometimes enclosed by a sac-like utricle (perigynium) or with a basal cup-like disk.

Distribution

91 genera and c. 5,500 species. Worldwide except Antarctica. Carex is the largest temperate genus.

Ecology

Particularly common in open wetlands but also found in a range of other habitats, including grasslands and forests.

Note

Rhizomatous, stoloniferous, or annual herbs. Culms 3-sided. Leaves grass-like. Inflorescence with 1–many partial inflorescences (spikelets or spicoids). Flowers minute. Fruit a hard, 1-seeded, nutlet, sometimes enclosed by a sac-like utricle.

Description Author

David A. Simpson & Martin Xanthos

Cyperaceae, Miss S.S. Hooper. Flora of West Tropical Africa 3:2. 1972

Morphology General Habit

Annuals or caespitose (tufted), rhizomatous, occasionally tuberiferous perennials (Microdracoides is pseudo-arborescent); underground stems bearing scales which grade into the culm leaves; culms generally leafy only at, or towards the base and generally unbranched below the inflorescence, solid, triquetrous, round, flattened or 5-angled; leaves with a distinct cylindrical sheath, closed (except in Coleochloa), generally without a ligule, prolonged at the apex on the side opposite the blade (antiligule) in species of Scleria and Afrotrilepis, and a generally linear blade (reduced to an apiculus in Eleocharis and elsewhere), not articulated with the sheath as in grasses, though deciduous in Coleochloa

Morphology Reproductive morphology Flowers

Flowers small, simple, often consisting only of stamens or pistil or both within a subtending glume, sometimes with accompanying hypogynous bristles, hairs or squamellae, arranged in bisexual or unisexual (Microdracoides, Carex, some Sclerieae) spikelets

Morphology Reproductive morphology Inflorescences

Spikelets sometimes solitary (always so in Eleocharis), more often aggregated into capitula, spikes or glomerules which in turn may be solitary or variously arranged, often in 1–3 times compound, unequally rayed umbels, subtended by 1-several, more or less leaf-like, bracts

Morphology Reproductive morphology Flowers Androecium

Stamens 1-numerous, often 3, anthers basifixed with two pollen sacs often with sterile tips and crest, opening lengthwise by a slit, often protandrous

Morphology Reproductive morphology Flowers Gynoecium

Ovary superior with one erect anatropous ovule, and generally 2–3 branched style

Morphology Reproductive morphology Fruits

Fruit indehiscent, nut-like (achene) generally lenticular or trigonous

Morphology Reproductive morphology Seeds

Seed erect with a small embryo and abundant mealy or fleshy endosperm

J. Browning, K.D. Gordon-Gray†, M. Lock, H. Beentje, K. Vollesen, K. Bauters, C. Archer, I. Larridon, M. Xanthos, P. Vorster, J. Bruhl, K. Wilson and X. Zhang (2020). Flora Zambesiaca Volume: 14: Cyperaceae. M.Á. García, J.R. Timberlake (Eds). Kew Publish

Morphology General Habit

Annual or perennial herbs, usually tufted with rhizomes or stolons; monoecious or hermaphrodite, rarely dioecious (in Scirpoides)

Morphology Culms

Culms solid or hollow, triangular or less often rounded, 4–6 angular or flattened, sometimes with transverse septa

Morphology Leaves

Leaves basal or cauline, usually 3-ranked with a closed sheath, rarely 2-ranked with an open sheath (in Coloeochloa); blade linear when present

Morphology Reproductive morphology Inflorescences

Inflorescence terminal or pseudolateral, umbellate, anthelate, capitate, spicate, paniculate, corymbose (or combinations thereof); with few to many spikelets, sometimes reduced to a solitary spikelet, or with spikelets aggregating into pseudo-spikelets often surrounded by conspicuous leafy bracts

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets consisting of few to many inconspicuous unisexual or bisexual flowers each subtended by a glume (bract)

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes spirally or distichously arranged, usually all fertile (occasionally only uppermost glume fertile)

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 1–3(6); filaments free, sometimes strongly elongating after anthesis; anthers basifixed, opening lengthwise by a slit

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary solitary and superior, 1-locular, of 2–3 joined carpels; hypogynous scales or bristles absent or 3–6; style 2–3-branched, rarely unbranched

Morphology Reproductive morphology Fruits

Fruit an indehiscent 1-seeded nutlet, sessile or nearly so, sometimes (in Carex, Schoenoxiphium) surrounded by a sac-like utricle.

Distribution

A family of 104 genera and 5000 species, particularly in the tropics and subtropics but with the large genus Carex well-represented in temperate zones.

Ecology

Often found in moist conditions and can be the dominant plants in wetlands.

Note

Recently the genera Alinula, Ascolepis, Kyllinga, Lipocarpha, Pycreus, Sphaerocyperus and Volkiella have been subsumed into the genus Cyperus sensu lato (Larridon et al. in Phytotaxa 166: 33–48, 2014; in Pl. Ecol. Evol. 144: 327–356, 2011; Bauters et al. in Phytotaxa 166: 1–32, 2014). In light of the recent nature of this change, and to ensure consistency with F.T.E.A., we are retaining the original genera here. Larridon et al. (2011, 2014) and Bauters et al. (2014) provided the necessary taxonomic changes to subsume the listed genera into Cyperus. The order of genera below follows that in F.T.E.A., based on Goetghebeur in Kubitzki (1998).

George R. Proctor (2012). Flora of the Cayman Isands (Second Edition). Royal Botanic Gardens, Kew

Morphology General Habit

Grass-like or rush-like herbs (rarely somewhat woody), annual or perennial, often with more or less elongate rhizomes

Morphology Culms

Culms usually erect, solid (rarely hollow), more or less 3-angled (rarely terete)

Morphology Leaves

Leaves linear or nearly so, 3-ranked, with closed sheaths at base, this lacking a ligule or the ligule very small; sometimes lacking a blade, the entire leaf then consisting of a tubular sheath

Morphology Reproductive morphology Inflorescences

Inflorescences simple in heads, or variously compound; flowers bi-sexual or unisexual, arranged in dense or loose spikelets, the individual flowers always solitary in the axils of deciduous or persistent papery scale- like glumes

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets 1–many-flowered, clustered or numerous, rarely solitary

Morphology Reproductive morphology Flowers Perianth

Perianth composed of bristles or small scales, rarely calyx-like, sometimes lacking

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens usually 1–3, the anthers 2-celled

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary superior, 1-celled, with a single erect ovule; style usually 2- or 3-cleft (rarely more divided)

Morphology Reproductive morphology Fruits

Fruit an achene.

Distribution

A large, world-wide family of about 106 genera and over 5,000 species, some of which are of economic importance.

Recognition

Members of this family are often mistaken for grasses.

Note

Most are wind-pollinated; exceptions include the white-bracted species of Rhynchospora; one of these (R. stellata) commonly occurs in Grand Cayman.

Cyperaceae, K Hoenselaar, B. Verdcourt & H. Beentje. Hypolytrum, D Simpson. Fuirena, M Muasya. Flora of Tropical East Africa. 2010

Morphology General Habit

Herbs, often tufted and with rhizomes or stolons, sometimes at base with very short internodes forming a tuber or corm

Morphology Stem

Stems solid or hollow, triangular or less often rounded or 4–6-angular or flattened, sometimes with transverse septa

Morphology Leaves

Leaves (sub)basal or with a few cauline, usually in 3 ranks, with a usually closed sheath and a linear blade, the lowermost often reduced to a sheath

Morphology Reproductive morphology Inflorescences

Inflorescence terminal (rarely pseudolateral), paniculate, spicate, anthelate or capitate or combinations thereof, with few to many spikelets, sometimes much reduced; often subtended by leafy involucral bracts

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets with few to many flowers, each subtended by a glume (bract).

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes spirally arranged or distichous.

Morphology Reproductive morphology Flowers

Flowers unisexual or bisexual

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 1–3(–6).

Morphology Reproductive morphology Flowers Androecium Stamens Anthers

Anthers basifixed, introrse

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary solitary and superior, 1-locular, of (2–)3 joined carpels; hypogynous scales or bristles absent or 3–6.

Morphology Reproductive morphology Flowers Gynoecium Style

Style most often with 2–3 branches

Morphology Reproductive morphology Fruits

Fruit a 1-seeded nutlet, sessile or nearly so, sometimes (in Carex, Schoenoxiphium) surrounded by a sac-like utricle.

Ecology

Often in moist conditions, and can be the dominant plants in wetlands.

Timothy Utteridge & Gemma Bramley (2020). The Kew Tropical Plant Families Identification Handbook, Second Edition. Kew Publishing Royal Botanic Gardens, Kew

Note

Rhizomatous, stoloniferous or annual herbs; culms 3-sided. Leaves grass-like. Inflorescence with 1–many partial inflorescences (spikelets or spicoids). Flowers minute. Fruit a hard, 1-seeded, nutlet, sometimes enclosed by a sac-like utricle.

Recognition

Characters of similar families: Poaceae: culms rounded or flattened, hollow, noded, leaves 2-ranked, lemma and palea present in floret. Juncaceae: flowers minute, regular, with perianth of 6 tepals, fruit a capsule with 3–many seeds. Pandanaceae: leaves with spines along the lower midrib all the way down to the leaf-base.

Morphology General Habit

Herbs, rhizomatous to stoloniferous, or annual-Culms mostly 3-sided, solid, rarely noded

Morphology Leaves

Leaves, mostly 3-ranked, usually linear, grass-like, sometimes broader with a pseudopetiole, sometimes a sheath only; ligule often present

Morphology Reproductive morphology Inflorescences Bracts Involucre

Involucral bracts 1–several, leaf- or glume-like

Morphology Reproductive morphology Inflorescences

Inflorescence simple or branched and umbel-like, or paniculate, with 1–many partial inflorescence units (spikelets or spicoids)

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets comprising 1–many spiral or 2-ranked glumes, each subtending 1 minute flower or sterile; spicoids comprising a female flower, 2–12 scale-like bracts, the outermost 2 bracts opposite and keeled, the spicoid subtended and usually hidden by a glume-like bract; perianth absent or bristle- or scale-like; stigmas 2–3

Morphology Reproductive morphology Fruits

Fruit a hard, 1-seeded, 2–3-sided nutlet, smooth or patterned, sometimes enclosed by a sac-like utricle (perigynium) or with a basal cup-like disk.

Distribution

106 genera and c. 5,500 species. Worldwide except Antarctica. The greatest generic diversity occurs in the tropics.

Ecology

Particularly common in open wetlands but also found in a range of other habitats including savannahs and forests, up to 5,000 m altitude.

Description Author

David Simpson

Use

Cyperaceae are of economic importance, especially in the tropics; some species are pantropical weeds. Uses include basketry, construction, food, matting, medicine and as ornamentals.