Muellera leptobotrys M.J.Silva & A.M.G.Azevedo, 2011

Silva, Marcos José Da & Tozzi, Ana Maria Goulart De Azevedo, 2011, Three new endemic species of Muellera (Fabaceae, Papilionoideae) from Brazil, Phytotaxa 29, pp. 41-50 : 44-46

Muellera leptobotrys M.J.Silva & A.M.G.Azevedo , sp. nov. ( Fig. 2 )

Species haec Muellera virgilioide et Muellera nitenti proxima , a quarum pseudoracemis pendulis, floribus irregulariter dispositis acranthis, bracteolis oblongo-elipticis, oppositis ad apicem pedicellis disposita sub finem anthesis, fructis chartaceis latissime ellipticis usque obovatis-ellipticis, seminis oblongo-reniformis hylis subterminalis recedit.

Type:— BRAZIL. Minas Gerais: Mun. Itaobim, BR 116 , após Ponto dos Volantes, 08 November 2000, C. V .

Mendoça Filho & R. Belinello 620 (holotype UEC!, isotype BHCB!).

Treelets to trees 5.5–20.0 m. Bark gray, glabrous. Branches cylindrical, when young usually pendulous, dark brown, glabrescent to shortly hyaline-pubescent or yellowish, lenticels small; when mature, glabrous, fissured or tuberculate basally. Leaves 5(–7)-foliolate; pulvinus 1.9–2.0 mm long, sparsely ferrugineoustomentose, transversally rugose; petiole 1.8–3.2 cm long, rachis 1.3–1.9 cm long, both conspicuously subquadrangular, strongly canaliculate above and hyaline-pubescent to ferrugineous, petiolule 2–3 mm long, subcylindrical, rugose transversally rugose, canaliculate above, glabrous to glabrescent; stipules caducous. Leaflets 3.0– 6.2 cm long, 2.0– 3.8 cm wide, opposite to rarely subopposite (1 st pair), the basal ones, ovate to ovate-elliptic or broadly orbicular, the medial ones elliptic to elliptic-obovate, and the terminal ones broadly elliptic to obovate; base oblique to cuneate, apex obtuse and shortly acuminate, chartaceous, adaxial surface glabrous, abaxial surface glabrescent to shortly hyaline-pubescent along the midrib; venation brochidodromous, secondary veins impressed on both surfaces, each forming an angle of 35–45 o with the midvein; tertiary veins reticulate. Pseudoracemes axillary, solitary or sometimes 2–3 in the termination of the branches leafless, multiflorous, lax, flowers aggregate or discontinuous along the rachis, peduncle 0.7–2.0 cm long, rachis 6.5–7.8 cm long, both angulate to subcylindrical, slender to robust, shortly ferrugineoustomentose and with linear secretory cavities; primary bracts, caducous, secondary bracts 0.6–0.7 mm long, 1.2–1.3 mm wide, depressed-trullate, apex obtuse, caducous from the floral buds, tertiary bracts 0.9-1.0 mm long, ovate; bracteoles 0.9–1.0 mm long, oblong-elliptic, apex obtuse, caducous, opposite, situated at the apex of pedicel. Bracts and bracteoles ferrugineous-tomentose externally and with secretory cavities. Flowers pink to lilac, calyx with secretory cavities from the base to more than half its length; pedicel 3.2–4.5 mm long, subcylindrical, shortly rusty-sericeous; calyx 4.9–5.0 mm long, 4.9–5.0 mm wide, campanulate, slightly gibbous on the upper side, rusty-sericeous externally, base cuneate to obtuse; vexillary lobe subtruncate, the 3 carenal lobes, shallowly triangular, unequal, acuminate at the apex, subcoriaceous; standard 10.0– 10.5 mm long, 11.9–12.0 mm wide; broadly ovate, apex discreetly emarginate, base attenuate, sericeous on the centralapical region of the dorsal face, claw 1.9–2.0 mm long; wings 9.9–10.0 mm long, 4.3–4.9 mm wide, ovate, apex obtuse, base sagittate on the vexillary margin, sericeous on the central-apical region of the dorsal surface, claw 4.4–4.5 mm long; keel petals 7.8–8.0 mm long, 3.3–3.4 mm wide, falcate, umbonate above the claw, apex obtuse, base attenuate on the vexillary margin, sericeous on the central-apical region of the dorsal face, claw 5.0– 5.1 mm long; staminal tube 7.8–8.0 mm long, 2.6 mm wide, membranaceous, glabrous, slightly bicallose, the free portion of the filaments indumented; anthers 0.8–0.9 mm long, oblongoid to lanceoloid, sericeous basally, apiculate; ovary 6.0– 6.2 mm long, ca. 1.8 mm wide, lanceolate, slightly curved, sericeous on the margin; style 3.9–4.0 mm long, sparsely sericeous; stigma punctiform, stipe 3.0– 3.2 mm long, ovules 6–7, reniform, hypanthium 0.9–1.0 mm long, asymmetrical. Fruit 4.5–6.0 cm long, 2.2–2.5 cm wide, 1- or more rarely 2-seeded, glabrescent, broadly elliptic to elliptic-obovate, chartaceous, base broadly obtuse to suboblique, apex obtuse to acuminate, vexillary margin nerviform, discreetly reticulate, light brown, stipe 0.7–0.8 cm long. Seeds 9–10 mm long, 7–9 mm wide, sub-oblong, flattened, light dark, smooth, and hilum subterminal with margin convolute on the upper third.

Distribution and ecology: —This species is probably endemic to the states of Minas Gerais and Bahia, located in the southeastern and northeastern regions of Brazil. It grows on the edge of seasonally dry tropical forests in clayey soils, and in caatinga vegetation, at 240–671 m of elevation.

Etymology: —The specific epithet leptobotrys is derived from the Greek words “ leptos” (slender) and “ botrys” (bunch of grapes), referring to the long and slender pseudoracemes of the species.

Phenology: —Flowering from September to December, and has been collected with fruits in April.

Relationships and characterization: — Muellera leptobotrys is characterized by its fruits chartaceous, broadly elliptic to elliptic-obovate, pseudoracemes with flowers discontinuous or aggregated along the rachises, flowers short-pedicelate (pedicel 3.2–4.5 mm), staminal tube sparsely indumented, and bracteoles situated on base of the calyx. The vegetative stems and aspect of leaves and leaflets of this species are very similar to M. virgilioides (Vogel) M.J. Silva & A.M.G. Azevedo and M. nitens which occur in the southeastern (Rio de Janeiro), and northeastern (Bahia and Pernambuco) regions of Brazil. More detailed morphological comparisons of these three species are given in table 1.

Table 1. Morphological characters distinguishing Muellera leptobotrys , M. nitens , and M. virgilioides .

Conservation status: —The species is currently known only from the states of Minas Gerais and Bahia, where it grows in seasonally dry tropical forests and caatinga vegetation. Both areas have been under intense threat of deforestation, especially for the extraction of timber and the introduction of cattle ranching. Due to current threats to the habitat of this species, it should be considered “Near Threatened” (NT) according to IUCN criteria ( IUCN 2001).

Additional specimens examined (paratypes):— BRAZIL. Bahia: Itaberaba, Fazenda Leão dos Brejos, 13 November 1983, G. C. Pinto 372 ( CEPEC) ; Itatim, Morro do Agenor , 12º42´S, 39º46´W, 240 m, 29 September 1996, França et al. 1864 ( CTES, ESA, HUEFS, RB) ; Jacobina, Serra da Jacobina , s.d., Blanchet 3421 ( BM, MICH, NY, P) ; Jequié, estrada que liga Jequié a Lafayete Coutinho, 11-17 km a sudoeste de Jequié, 19 November 1978, Mori et al. 11226 ( CEPEC, K, RB) ; Idem, Morro da Torre 13º53´27´´S, 40º7´20´´W, 671 m, 13 April 2007, Queiroz et al. 13016 ( HUEFS) ; Morro do Chapéu , no caminho para a Cidade das Pedras, 11º40´22´´S, 41º00´39´´W, 9 December 2006, Guedes 12894 et al. ( ALCB) ; Paraguaçu, Itaête, Assentamento Baixão , área de loteamento, 13º10´S, 41º2´W, 15 April 2001, Santana 244 et al. ( ALCB, CEPEC) ; Piritiba , ca. 8 km de França na estrada para Piritiba, 11º28´13´´S, 40º36´19´´W, 534 m, 2 November 1997, França et al. 2475 ( HUEFS) ; Rui Barbosa, estrada para Barro Duro , 12º18´4´´S, 40º27´29´´W, 387 m, 14 November 2004, Queiroz et al. 9804 ( HUEFS) . Minas Gerais: Serra de Antonio , November 1882, Glaziou 12592 ( C) .

Figures

FIGURE 2. Muellera leptobotrys. A. Flowering branch. B. Leaflet. C. Floral bud. D. Detail of inflorescence. E. Bracteoles. F. Calyx opened out. G. Standard. H. Wings. I. Keel petals. J. Staminal tube. K. Open staminal tube. L. Anthers (dorsal and ventral views). M. Gynoecium. N. Fruit. O. Seed. (A–M. C.V. Mendonça Filho & R. Belinello 620; N–O. Santana, D.L. et al. 244)