Cladium P.Browne (Browne 1756: 114)

Rasaminirina, Fitiavana & Larridon, Isabel, 2023, The genera of Cyperaceae of Madagascar, Plant Ecology and Evolution 156 (3), pp. 276-310 : 276

Cladium P.Browne (Browne 1756: 114)

Type species.

Cladium jamaicense Crantz [= Cladium mariscus subsp. jamaicense Kük.]

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.

Figures

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).