Cephalocarpus martinhae S.M.Costa, 2024

Costa, Suzana Maria, Thomas, William Wayt & Amaral, Maria Do Carmo Estanislau Do, 2024, Four new species from Venezuela and identification key to Cephalocarpus (Cryptangieae, Cyperaceae), Phytotaxa 670 (2), pp. 119-126 : 122-124

3. Cephalocarpus martinhae S.M.Costa , sp. nov. ( Figures 1C , 2C , 3C )

Similar to Cephalocarpus angustus by the densely pubescent, shiny and light green leaves. C. martinhae differs by its visibly shorter female spikelets ((1.8) 2–3.5 long in C. martinhae and 5.8–6.9 mm long in C. angustus ) and dark-brown to blackish glumes (instead of paleaceous glumes in C. angustus ).

Type specimen:— VENEZUELA. Amazonas: Rio Negro, Neblina Massif , 500–700 m, 0°50’N 66°06’W, 15 July 1984, G. Davidse 27378 & J. S. Miller ( NY! – holotype; MO! – isotype) .

Monoecious herb: sexes mostly at separate paracladia (male at basal and female at apical ones), monomorphic. Caudex ~ 1–2 mm (2–7 mm including fibrous sheaths remains and adventitious roots). Leaf: sheath glabrous, dark brown; blade (8) 20–25 × 0.2–0.3 cm, linear-lanceolate, margin sparsely pubescent, generally concolorous, light green to green. Inflorescence panicle-like, (5) 8–12 paracladia; culm (20) 45–60 × (0.06) 0.09–0.15 cm, compressed, glabrous. Paracladia (lowermost) up to 12 cm long, 3–4 orders; peduncle – 8.5 cm long, compressed, glabrous. Involucral bract (lowermost) leaf-like or reduced to sheath: sheath 1–2 cm long, glabrous, dark-brown; blade 1–3 × 0.07 cm, “V”- shaped, glabrous, dark-brown. Male spikelet 3–5.5 × 0.8–1.1 mm, 7–9 glumes, 4–5 flowers,1–2 each cluster; glume (outermost) ~ 1.5–3.7 mm long, glabrous, mucronate (mucron ~ 0.3–1.5mm long), dark-brown; stamens 4, connective projection short-conical with short trichomes. Female spikelet (1.8) 2–3.5 × (0.45) 0.6–0.8 mm, 4–5 (7) glumes; glume (outermost) ~ 1.9–3mm long, glabrous, mucronate (mucron ~ 0.3–0.5 mm long), dark-brown; stigma 3. Fruit 3–5.5 × 0.8–1.7 mm, oblong-elliptic, smooth, ciliate to pubescent apex, main body continuous to the beak; hypogynous scales 1–1.4 mm long, elliptic, trichome 0.7–1 mm long; beak 1–2.5mm long, narrow-conical, ciliate or pubescent especially at base.

Etymology:—This species is named in honor of my friend Marta Regina Silva Pereira (a.k.a. Martinha), an enthusiastic bryologist, an exciting biology teacher and captivating person. Despite all the obstacles, she enjoys the good opportunities of life and always has a smile and a hug for everyone.

Distribution:—It is known from Cerro de la Neblina (Amazonas, Venezuela).

Taxonomic notes:— Cephalocarpus martinhae morphologically resembles C. angustus (N.E.Brown)(1901:73) S.M. Costa (2021a:48), but it is quite different due to the narrower and less pubescent leaves, the shorter female spikelets, and the fruit with pubescent beak. It is possible to notice a gradual increase of pubescence and lowermost male glume size and decrease of the leaf length at higher altitudes at this species. As it is registered at the Venezuelan side of Serra da Neblina it probably also occurs at Brazilian areas in this tepui.

Examined Material (additional):— VENEZUELA. Amazonas: Rio Yatua, 11 December 1957, B. Maguire 42341 & J. J. Wurdack & C. K. Maguire ( NY!) ; Cerro de la Neblina, slope N of Rio Mawarinuma, 500–700 m, 0°50’N 66°05’W, 25 April 1984, B. A. Stein 1671 & A. Gentry ( NY!, MO) ; Cerro de la Neblina camp 2, Neblina Massif, 2100 m, 0°49’40”N 65°59’W, 15 April 1984, B. A. Stein 1572 & A. Gentry ( NY!, MO) ; Rio Negro, Cerro de La Neblina above Puerto Chimo Camp on Rio Mawarinuma , 150–500 m, 00°50’N 66°07’W, 14 February 1984, R. Liesner 15902 ( NY!, MO) .

Figures

FIGURE 1. Male and female spikelets and fruits of Cephalocarpus spp. nov. A. C. chimantensis S.M.Costa; B. C. marahuacensis S.M.Costa; C. C. martinhae S.M.Costa; D. C. pyramidalis S.M.Costa (black bars = 1 mm; drawings of SMC).

FIGURE 2. Currently known distribution maps of Cephalocarpus spp. nov. A. C. chimantensis S.M.Costa; B. C. marahuacensis S.M.Costa; C. C. martinhae S.M.Costa; D. C. pyramidalis S.M.Costa.

FIGURE 3. Holotypes of Cephalocarpus spp. nov. A. Cephalocarpus chimantensis S.M. Costa; B. Cephalocarpus marahuacensis S.M. Costa; C. Cephalocarpus martinhae S.M. Costa; D. Cephalocarpus pyramidalis S.M. Costa. (images from the NYBG C.V. Starr Virtual Herbarium).