Pilea brasiliensis Gaglioti, Romaniuc & A. K. Monro 2011, sp. nov.

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 brasiliensis Leaf and petiole lengthequal or subequal at the same node Staminate inflorescenceflowers borne in a panicle Achenes0.75–1.00 mm Pilea lippioidesunequal by ratio 1.0:1.5–3.0 at the same nodeflowers borne in a compact head1.20–1.50 mmPublished 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/489411

Data from: Phylogeny of Cecropieae (Urticaceae) and the evolution of an ant-plant mutualism

Ant-plant mutualisms are abundant in the tropics and are popular models for ecological study, but investigating the origin and evolution of such systems requires a phylogenetic framework. A common ant-plant mutualism in the Neotropics involves the genus Cecropia, a group of fast-growing pioneer trees that are important in forest regeneration. Relationships between genera in the tribe Cecropieae (Urticaceae), including Cecropia, Coussapoa, Musanga, Myrianthus, and Pourouma, are unknown and are necessary to investigate the evolutionary history of the Cecropia-ant mutualism. Bayesian phylogenetic analyses of the NADH dehydrogenase (ndhF) chloroplast gene region, the 26S region of nuclear ribosomal DNA, and an exon-primed intron-crossing DNA region support the position of non-myrmecophytic African Musanga within a paraphyletic Cecropia. Neotropical Pourouma and Coussapoa are supported as sister taxa with African Myrianthus as their closest relative. Although it remains uncertain whether myrmecophytism was the ancestral condition of the Cecropia clade, a close relationship between non-myrmecophytic Cecropia sciadophylla and Musanga suggests that the loss of ant associations did not accompany African colonization