Scleria angusta

Goetghebeur, P. & Larridon, I., 2019, A revision of Scleria (Cyperaceae) in Madagascar, Blumea 64 (3), pp. 195-213 : 207-208

20. Scleria angusta Nees ex Kunth

Scleria angusta Nees ex Kunth (1837) 346. — Type: Drège 4246 (lectotype designated here: P00462002; isolectotypes P00462000, P00462001, K000363518, K000363519), Madagascar, Cap. b. Spei., 1 Mar. 1832 .

Scleria angustata Steud. (1841) 542. — Type: not located.

Perennial. Culm 1–2.5 m by 3–4 mm, triangular, mainly glabrous, sheath occasionally puberulent. Leaves 30–40 by 1.2–2 cm, largely acuminate, pleated when pressed, pseudopraemorse. Medium leaves closely arranged, sheaths completely covering the culm; antrorse-hairs usually present along margins and distal third of the central nerves on the abaxial side; contraligule triangular, rounded, puberulous, purplish. Inflorescence a panicle with leafy bracts, pyramidal, terminal, 7–12 cm long, laterals solitary and at least the most basal shorter than the internode ( Fig. 1c ); peduncle only visible in the basal panicles, generally less than 5 cm long. Spikelets unisexual or subandrogynous; rachilla pale brown to greenish, sometimes reddish, flattened; prophyll, rachilla and bracts of the spikelet glabrous, sometimes hairy; glume bearing male flower 3–4 mm long, female 3 mm, shortly mucronate, straw-coloured, mucronate, ciliate at the base. Nutlet ovoid to piriform, 2–2.5 mm long, 1.5–2 mm diam, white to purple, smooth, shiny; hypogynium heart-shaped, laciniate, especially on the lobes ( Fig. 2m –n ).

Distribution — South Africa and Madagascar. South Africa: patchy distribution along the coast of Natal. Madagascar: along the east coast, and more rarely in the Central region.

Habitat & Ecology — In swamp forest ( Gordon-Gray 1995), in wetlands, more rarely close to rivers and lakes, alt. 0–1000 m.

Conservation — Scleria angusta is native to Madagascar and found also in South Africa. This is a widespread species, which is found in the Mananara Nord and Isalo protected areas. The estimated of EOO is much larger than the threshold for a threatened category. Furthermore, there are no major threats which affect this species. Hence, it is assessed as Least Concern.

Additional specimens. MADAGASCAR, L’Ouest de l’Isalo , 30 July 1928, H. Humbert 5055 (K, P0189809, TAN001250 ); ibid., 700–800 m, Mar. 1934, H. Humbert 13750 (P01898854) ; Antananarivo, Oct.1882, R. Baron 1435 (K, P01707789) ; Antsiranana, Daraina,Antsahabe Forest , 550 m, 11 Jan. 2004, L. Nusbaumer LN916 (K) ; Toamasina, Tamatave , 26 July 1912, K. Afzelius s.n. (K) ; Toliara, Tôlanaro, Ste. Luce, 10 m, 20 Oct. 1989, R. Rabehovitra 2062 (K, MO); Soomierana , 10 Oct. 1932, R. Decary 10768 (K) .

Note — The niche of this species is the same in Madagascar and South Africa. Therefore, it probably diversified in Madagascar, along with the rest of Abortivae group, and dispersed to South Africa.

Figures

Fig. 1 Main types of inflorescences of Scleria from Madagascar. a. Inflorescence of S. rosea; b. inflorescence of S. trialata; c. inflorescence of S. angusta; d. truncated panicle of S. melanomphala; e. truncated panicle of S. greigiifolia; f. truncated panicle of S. foliosa; g. spicate-glomerulate inflorescence of S. distans; h. panicle of S. hilsenbergii; i. inflorescence of S. lithosperma (a: Ramandimbimanana & Randimbiarison 460; b: Lance 30; c: Mogg 288898; d: Brummit & Singe 232; e: Bosser 15031; f: Raynal 7664; g: Croat 29582; h: Rajaonary 45; i: Frontier-Tanzania Coastal Programme Research Forest 412; all K). — Scale bar: a = 7 cm, b–h = 5 cm, i = 4 cm.

Fig. 2 Nutlets of Scleria species occurring in Madagascar. a–b. S. madagascariensis; c–d. S. trialata; e. S. baronii; f. S. perpusilla; g–h. S. rosea; i–j. S. hilsenbergii; k–l. S. rutenbergiana; m–n. S. angusta; o. S. andringitrensis (a–b: Rakotozafy 2741; c–d: Lance 30; e. Hoffman 221; f. Decary 7695; g–h: Ranarivelo 282; i–j. Rajaonary 45; k–l: Wilkin 941; m–n: Boivin s.n.; o: Perrier de la Bâthie 14385; all K).