Bulbostylis amazonica Prata & M.G.López, 2017

1. Bulbostylis amazonica Prata & M.G.López View in CoL , sp. nov.

Type:— BRAZIL. Amazonas: Rio Negro, Temedauí, river bank 2 hours below Tapuruquara , 04 September 1979, K. Kubitzki, Calderón & H.H. Poppendieck 79–120, (holotype MG! , isotypes INPA , EAFM ). Figures 1 View FIGURE 1 and 2 View FIGURE 2 .

Bulbostylis amazonica has anthelate inflorescences with the spikelets united in fascicles similar to those found in B. fasciculata Uittien and B. vestita (Kunth) C.B. Clarke. Bulbostylis amazonica differs from these two species in having hispid leaves and scapes and 3–9 fascicles, each on a developed branch, with each fascicle having 2–10 spikelets.

Perennial, cespitose, 10–35 cm tall, the base pale castaneous and not thickened. Leaves 6–18 × 0.02 cm, 1/2 the length of the scape; sheaths 1.5–3 cm long., membranaceous, glabrous except for the oblique and densely ciliate apex, the trichomes white; blade erect, setaceous, glabrous, the adaxial surface concave, the abaxial surface slightly canaliculate, the margins thickened, antrorsely-scabrous. Scape 0.6 mm diam., cylindrical, longitudinally linear, glabrous. Involucral bracts 3–5, sub-erect, leaflike, glabrous the basal bract 1–2 cm long, much shorter than the inflorescence, sometimes slightly exceeding the inflorescence, the base dilated, the margins ciliate. Inflorescence 0.5–2 × 0.5–1.5 cm, anthelate, simple, with 3–9 fascicles on each developed branch, each fascicle with 2–10 spikelets, some more developed than others. Spikelets 4–5 × 1–2 mm, ovoid, with 3–9 flowers. Glumes 1–1.3 × 0.6–0.8 mm, deciduous at maturity, leaving a scar on the spikelet axis, lanceolate, navicular, membranaceous, pale castaneous, trinerved, the apex acute, the mucro excurrent and straight, the surface papillose and pubescent, the margins hyaline, lacerate and ciliate. Flowers with 3 stamens, the anthers 0.4 mm long, linear; the style trifid 0.5 mm long, the branches 0.3 mm long. Achene 0.4–0.6 × 0.3–0.4 mm, obovoid, trigonous, trilobate, the base attenuate, dark castaneous at maturity, the surface reticulate, shiny, formed by pentagonal to hexagonal cells, silica bodies plane in superficial view, the stylopodium persistent, pyramidal, dark castaneous, 1/8 the length of the achene.

Habitat and distribution: — Venezuela and Brazil (Amazonas, Pará and Mato Grosso). Non-flooded (terra firme) forests, open savannas (campinas), white-sand savannas (campinaranas). In sandy soil.

Paratypes:— BRAZIL. Amazonas: Rio Cuieiras, 50 km, 01 April 1974, Ongley, J.C. & Ramos, J.F.P21765 ( NY) . Rio Cuieiras, 2 km do Rio Cuieiras a 2 km below mouth of Rio Bracinho , 14 November 1973, Prance, G.T. 17927 et al. ( NY) . Estrada Terra Preta Km 2, ramo Manaus Manacapuru, 5 km de Cacau Pereira , 18 July 1975, Prance, G.T. 23516 et al. ( NY) . Barcelos: 14 km ao NW da ponta SW da Serra de Aracá , 00°48’N, 63°21’W, July 1985, Huber, O. 10715 et al. ( NY) GoogleMaps . Manaus: Igarapé do Passarinho , 2 November 1961, Rodrigues, W. 3252 & Coelho, L. ( NY) . Km 63, Estrada Manaus Itacoatiara , 17 November 1968, Prance, G.T. 9065 et al. ( NY) . Estrada Manaus Itacoatiara, Rio Urubu , 5 April 1967, Prance, G.T. 4792 et al. ( NY) . Estrada Manaus-Caracaraí, km 62, Reserva INPA , 5 February 1974, Steward, W.C. P20218 & Ramos, J.F. ( NY) . Ponta Negra: Banks of Rio Negro , 22 May 1968, Philcox, D. 4832 et al. ( NY) . Ponta Negra, 16–18 km N de Manaus no Rio Negro , 17 December 1974, Gentry, A. 13389 ( NY) . Presidente Figueiredo: Rodovia BR-174, Manaus-Caracas , ao longo da estrada, 14 November 1999, Alves, M. 1674 & Amorim, A. ( NY) . Mato Grosso: Parque Nacional do Xingú, Aldeia dos Camaiurás , 1965, Coelho, D. 15857 ( NY) . Pará: Oriximiná, Rio Mapuera a 30 km da Cachoeira Porteira, margem esquerda a 5 km da margem do rio , 30 June 1980, Cid, C.A. 1216, Ramos J. & Mota C.D. ( NY) . VENEZUELA: Bolívar: Roscio, sabanas y arbustales en el valle del Río Guarí, aprox. 2 km al N de la entrada al Hato “La Divina Pastora”, al W de la carretera Luepa-Santa Elena , 4°43’N, 61°03’W, 900 m, 25 July 1983, Huber, O. 7849 & Alarcon, C. ( NY) GoogleMaps .

Notes:— Bulbostylis amazonica has anthelate inflorescences with the spikelets united in fascicles. These characters are similar to those found in two other South American species: Bulbostylis fasciculata Uittien (1926: 338) and Bulbostylis vestita (Kunth) C.B. Clarke (1900: 87) . Bulbostylis fasciculata differs in having 3–5 spikelets with the central one sessile and the others at the ends of elongate axes versus inflorescence with 3–9 fascicles on developed branch, each fascicle with 2–10 spikelets, located generally in the same length, sometimes any more developed than others. Bulbostylis vestita differs from B. amazonica in having hispid leaves and scapes.

Attempting to identify specimens of Bulbostylis amazonica using the key to species in the Flora of the Venezuelan Guyana ( Kral 1998) results in an identification as Bulbostylis junciformis (Kunth) C.B. Clarke ex Moore (1895: 512) . The latter differs from B. amazonica in having longer achenes (0.7–0.8 mm) and a recurved mucro on the glumes.

In his treatment of Oncostylis junciformis (Kunth) Nees (1842: 86) described several varieties and forms. None of the infraspecific variation described by him matches the morphology of Bulbostylis amazonica , nor does the distribution of any of those taxa match that of the new species. Nevertheless, B. amazonica is similar to B. junciformis in general habit and inflorescence structure. The differences between these two species are presented in Table 1 View TABLE 1 .