The genera of Cyperaceae of Madagascar Author Rasaminirina, Fitiavana https://orcid.org/0000-0003-0162-7975 University of Antananarivo, Antananarivo, Madagascar Author Larridon, Isabel https://orcid.org/0000-0003-0285-722X Kew Madagascar Conservation Centre, Antananarivo, Madagascar & Royal Botanic Gardens, Kew, Richmond, UK i.larridon@kew.org text Plant Ecology and Evolution 2023 2023-08-29 156 3 276 310 http://dx.doi.org/10.5091/plecevo.98847 journal article http://dx.doi.org/10.5091/plecevo.98847 2032-3921-3-276 BC5E6BD70022518ABF185FC3C18147CE Cladium P.Browne (Browne 1756: 114) Type species. Cladium jamaicense Crantz [= Cladium mariscus subsp. jamaicense Kuek .] Description of the genus. Robust perennials, up to several meters tall; rhizomatous, sometimes with swollen stolons. Culms with few-noded, internodes hollow. Leaves basal and cauline, V-shaped to flat, midribs and margins scabrid, eligulate. Involucral bracts leaf-like, sheathing. Inflorescence terminal or some lateral, paniculate; partial inflorescences anthelate. Spikelets numerous, short stalked or sessile. Glumes few to many, spirally arranged, persistent, increasing in length, with 2-3 upper glumes fertile. Lower floret mostly functionally male, upper florets bisexual. Perianth absent. Stamens 2-3. Style 2-3-fid, with a thickened persistent base. Nutlets ovoid, with a thick corky beak, surface smooth to wrinkled. Embryo small and poorly developed, broadly obovate in outline, with a basal, poorly developed root cap and without a leaf primordium. Distribution and ecology. Cladium is a cosmopolitan genus ( POWO 2022 ). It grows in estuaries, freshwater wetlands, and lake margins up to 1500 m in elevation. In Madagascar, it is only known from the north where a single taxon, i.e. Cladium mariscus subsp. jamaicense (Fig. 5 ), has been recorded in the Sava region of Antsiranana province. Figure 5. Cladium mariscus subsp. jamaicense . A . Habit. B . Inflorescence. C . Plant base, longitudinal section. D . Detail of leaf. E . Nutlet and upper unisexual floret with 2 filaments and rudimentary gynoecium. F . Spikelet. All from Ward 9082 . Scale bars: A = 25 cm; B, C = 5 cm; D = 1 cm; E, F = 2 mm. Drawn by Jane Browning, reproduced with permission from the artist, originally published in Gordon-Gray (1995) .