Cephalocarpus chimantensis S. M. Costa 2024, sp. nov.

1. Cephalocarpus chimantensis S.M.Costa, sp. nov. (Figures 1A, 2A, 3A). Similar to Cephalocarpus longibracteatus and C. rigidus, regarding the arrangement of leaves and inflorescence, but differs from both species by the developed peduncle of the spikelets, fruits (up to 0.6 mm long) with truncate apex and short conical beak without narrow neck between main body and beak. Type specimen:— VENEZUELA. Bolívar: Piar, Macizo del Chimantá, Sección oriental del Chimantá-tepui, cabeceras del afluente derecho superior del río Tirica (“ Caño del Grillo ”), 2450 m, 5°18’N 62°03’W, 7-9 February 1983, J. A.Steyermark 128931 & O. Huber, V.Carreño (NY! – holotype; VEN?) Monoecious herb: sexes intermingled at paracladia, monomorphic. Caudex ~ 1.3 mm diam. (4–5 mm diam. including sheaths remains and adventitious roots). Leaf: sheath pubescent, greenish or brown; blade 3–4.5 × 0.13–0.15 cm, linear-lanceolate, margins and midrib glabrous or sparsely pubescent, concolorous, greenish to reddish-brown after drying. Inflorescence panicle-like, with 2 paracladia; culm 3 –4.5 × 0.05 –0.07 cm, compressed, glabrous or with rare trichomes. Paracladia (lowermost) up to 1 cm long, 1 order; peduncle up to 0.6 cm long, compressed, glabrous to sparsely ciliate. Involucral bract (lowermost) leaf-like: sheath up to 3 mm long, pubescent, reddish-brown; blade 10–13 mm long, “M”-shaped, pubescent, reddish-brown to brownish-green. Male spikelet 3.5–4.5 × 0.7–0.9 mm, 5–6 glumes, 1–2 flowers; glume (outermost) – 2.5 mm long, mucronate (mucron up to ~ 0.1 mm long); stamens 2, connective projection not observed. Female spikelet ~4 × ~ 1 mm, 4–5 glumes; glume (outermost) – 2.5 mm long, mucronate (mucron up to ~ 0.1 mm long); stigmas 3. Fruit 1.3– 1.5 × 0.4–0.6 mm, obtriangular, smooth, short ciliolate at apex, reddish-brown, with truncate apex; hypogynous scale ~ 0.3 mm long, elliptic to orbicular, trichomes <0.01 mm long (sparse); beak ~ 0.3 mm long, short conical, glabrous. Etymology:—The name of the species refers to the type locality, the Chimantá Massif (Bolívar, Venezuela). Distribution:—This species is known only from its type locality, in the Chimantá Massif (Bolívar, Venezuela), at altitudes above 2450 m high. Taxonomic notes:— Cephalocarpus chimantensis is morphologically similar to C. longibracteatus Gilly ex Gleason & Killip (1939: 153) and C. rigidus Gilly ex Gleason & Killip (1939: 152), but differs from both by the presence of a peduncle up to 0.6 mm long below the spikelets (sessile in the other two species), and the fruit with a short conical beak and lacking the narrow neck between the beak and the main body. Examined Material (additional):— VENEZUELA. Bolívar: Piar, Macizo del Chimantá, Seccion oriental del Chimantá-tepui, cabeceras del afluente derecho superior del rio Tirica (“ Caño del Grillo ”), 2450 m, 5°18’N 62°03’W, 7– 9 February 1983, O. Huber 7183 & J. A.Steyermark (NY!); Chimantá Massif, east-south portion of summit of Apacará tepui, 2450–2500 m, 21–22 June 1953, J. A. Steyermark 75933 (F! – 2 sheets).