Pilea brasiliensis Gaglioti, Romaniuc & A. K. Monro 2011, sp. nov.
Creators: name: Gaglioti, A. L.
name: Romaniuc, S.
name: Monro, A. K.
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Rosales
Urticaceae
Pilea
Pilea brasiliensis

description: Pilea brasiliensis Gaglioti, Romaniuc & A.K. Monro, sp. nov. (Fig. 1)
A Pilea lippioides similis, sed foliis et petiolis eadem node aequalis aut subaequales longitudine, inflorescentiis staminalibus in panicula, seminibus minoribus, differt.
Type:— BRAZIL. Distrito Federal: Rio Maranhão, Via DF-2 Fazenda Maranhão, 27 February 1979, Heringer et al. 1039 (holotype IBGE!, isotype UEC!).
Perennial herb to 30 cm, terrestrial, epipetric, monoecious. Stem erect, sparsely branched to unbranched, drying brown-green to grey-green, glabrous; cystoliths elliptic; rooting at the base; internodes 8–45 mm, woody stems striate, hollow at 5 mm in diameter. Stipules persistent, 0.8–1.5 × 0.5–1.0 mm, deltate, drying brown-green, membranous, base triangular, apex obtuse. Leaves petiolate, petiole 4–30 mm, of equal or subequal length at the same node, glabrous; laminas of leaves equal or subequal at the same node, 15–55 × 1.5–40.0 mm, ovate to narrowly ovate, elliptic, smaller leaves, 4–10 × 4–8, frequently deltoid to suborbicular, membranous to chartaceous; upper surface drying dark green, green to yellowish green and often translucent, glabrous, lower surface drying dark green, green to yellowish green and often translucent, glabrous, cystoliths fusiform, occasionally appearing V- or Y-shaped, scattered; primary venation pinnate, secondary veins 4–11 pairs, 55°–75° to the midrib, weakly curved to curved; base obtuse to rounded; margin serrate or entire; apex acute. Inflorescences 4–12 per stem, unisexual, peduncular bracts 0.8–1.2 mm, narrowly ovate. Staminate inflorescences 1 or 2 per axil, 6–24 mm, bearing 6–28 flowers in an asymmetrical panicle; peduncle ¼–⅓ of the inflorescence length, glabrous; flowers 1.2–2.5 mm immediately prior to anthesis, drying cream, apically green; pedicels 0.8–1.2 mm, glabrous; tepals 4, 1.5–2.8 mm, glabrous, the subapical appendage 0.5 mm, corniculate. Pistillate inflorescences 1 or 2 per axil, 5–25 mm, bearing 22–85 flowers in an asymmetrical panicle, ¼–½ of the inflorescence length, glabrous; pedicels 0.25–0.5 mm, glabrous; tepals 3, unequal, dorsal tepal 0.5–1.0 mm, oblong, lateral tepals 0.25–0.5 mm, narrowly ovate. Infructescences 10–35 mm, tepals persistent; achenes 0.75–1.00 × 0.50–0.75 mm, compressed, narrowly ovoid to elliptic, greenish brown, glabrous.
Distribution:— Central Brazil. Distrito Federal, Mato Grosso, Minas Gerais and Goiás. Using Google Earth (accessed 13 June 2011) we calculated an Extent of Occurrence of ca 52,000 km 2, at 400 to 1200 m in semi-deciduous forest on limestone outcrops.
Etymology: — Named for the country in which the species is known to occur.
Additional specimens examined: — BRAZIL. Distrito Federal: Brasília, Rio Maranhão, Via DF-2 Fazenda Maranhão, 15°37’20”S, 47°40’38”W, fl. ♂ ♀, 27 February 1979, Heringer et al. 1039 (IBGE, UEC); Catetinho, 15°56’08”S, 48°00’35”W, fl. ♂ ♀, 8 March 1965, Smith A-2 (UB); Fercal, 15°38’01”S, 47°49’01”W, fr., 5 March 1965, Smith 15022 (P). Mato Grosso: Nobres, about 42 km NE (straight) of Nobres, area of Lago Azul, 14°35’00”S, 56°12’00”W, fl. ♂ ♀, 24 May 1997, Souza et al. 17155 (ESA). Minas Gerais: Januária, river valley Peruaçu, Boqueirão da Onça, 15°07’35”S, 44°15’17”W, fr., 24 May 1997, Salino 3086 (RB). Goiás: 50 km N of Corumbá on road to Niquelândia, in valley of Rio Maranhão, 800 m, 15°25’14”S, 48°19’50”W, fl. ♂ ♀, 24 January 1968, Irwin et al. 19106 (MBM).
Discussion: — Pilea brasiliensis belongs to the Dentatae -group of Weddell (1869) and the Fallaces - group of Killip (1936). It represents the first record of the Fallaces -group in Brazil. It is characterised by being glabrous, with toothed pinnately veined leaves, petioles of up to 3 cm long and paniculate inflorescences. Pilea brasiliensis closely resembles P. lippioides Killip (1925: 296), which occurs in the eastern and central Cordillera of Colombia, at elevations between 2400 and 3000 m. The two species may be readily distinguished by leaf and petiole morphology, staminate inflorescence arrangement and achene size as summarized here:Pilea brasiliensisLeaf and petiole lengthequal or subequal at the same nodeStaminate inflorescenceflowers borne in a panicleAchenes0.75–1.00 mmPilea lippioidesunequal by ratio 1.0:1.5–3.0 at the same node flowers borne in a compact head 1.20–1.50 mm
description: Published as part of Gaglioti, A. L., Romaniuc, S. & Monro, A. K., 2011, Pilea brasiliensis: a new species of Pilea (Urticaceae) from Central Brazil, pp. 17-20 in Phytotaxa 26 on page 18, DOI: 10.11646/phytotaxa.26.1.3, http://zenodo.org/record/4894114