Muellera nitens 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 : 46-49

Muellera nitens M.J.Silva & A.M.G.Azevedo , sp. nov. ( Fig. 3 )

Species haec Muellera virgilioide et Muellera leptobotrydis proxima , a quarum fructis lanceolatis carthaceis margine superioribus nerviformis, alabastris, bracteis secundariis tertiarisque et bracteolis eglandulatis, alis obovatis et ovariis centraliter glabris recedit.

Type: — BRAZIL. Bahia: Palmeiras, estrada para a Cachoeira da Fumaça a 7 km da cidade, 19 January 2002, Schultz et al. 1328 (holotype UEC!, isotypes K!, NY!) .

Shrubs or small trees 1.7–6.0 m. Bark dark grey to reddish, glabrous. Branches cylindrical, glabrous to glabrescent, striated, and with conspicuous, rounded or linear cream-coloured, lenticels; Leaves 5–foliolate, pulvinus 1.5–1.8 mm long, discreetly striated, glabrescent to rusty-sericeous; petiole 2.0– 3.8 cm long, rachis 0.8–3.0 cm long., both strongly subquadrangular, conspicuously canaliculate above, glabrescent to hyalinepubescent, petiolule 2–3 mm long, subcylindrical, rugose transversally, short-pubescent, trichomes reddish; stipules caducous. Leaflets 3.3–8.5 cm long, 1.5–3.2 cm wide, opposite, the basal ones ovate, the medial ones narrowly elliptic to elliptic-obovate, and the terminal ones broadly elliptic to obovate; base usually oblique, sometimes cuneate, apex conspicuously acuminate, chartaceous, distance between each pair of leaflets 0.9– 1.0 cm long, discolorous, adaxial surface bright green, sparsely pubescent along the veins, abaxial surface pale green, shortly hyaline-sericeous to glabrescent; venation brochidodromous, secondary veins impressed on both surface, each forming an angle of 35–45 o with the midvein; tertiary veins reticulate. Pseudoracemes axillary, solitary, lax; peduncle 0.5–1.2 cm long, rachis 4.6–7.0 cm long, both angulate, robust, shortly ferrugineous-tomentose, without secretory cavities; primary bracts, caducous, secondary bracts 0.8–0.9 mm long, 0.5–0.6 mm wide, ovate, apex obtuse, ciliate, persistent, tertiary bracts 0.6–0.7 mm long, oblong-ovate, apex rounded; bracteoles 0.9–1.0 mm long, ovate, apex acute, persistent, subopposite or alternate and situated on upper third of pedicel. Bracts and bracteoles ferrugineous-tomentose externally, without secretory cavities. Flowers pink, purplish to reddish, calyx sometimes with secretory cavities on the base of lobes, pedicel 8–10 mm long, subcylindrical, slender, shortly ferrugineous-sericeous; calyx 3.8–3.9 mm long, 3.7–4.8 mm wide; broadly campanulate, discretely gibbous on the upper side, base subrounded, ferrugineous-sericeous externally, purplish to reddish, subcoriaceous, vexillary lobe truncate, the 3 carenal lobes, triangular, shallowly triangular, apex obtuse; standard 12.0– 12.1 mm long, 13.7–13.8 mm wide; broadly ovate to orbicular, apex entire to discreetly emarginate, base rounded, not bicallose, ferrugineous-sericeous on the central-apical region of the dorsal surface, claw 3.9–4.0 mm long, 4.9–5.0 mm wide; wings 10.3–10.4 mm long, 5.4–5.5 mm wide, obovate, apex rounded, sericeous on the central-apical region of the dorsal surface, base sagittate on the vexillary margin, claw 4.9–5.0 mm long; keel petals 8.9–9.0 mm long, 4.3–4.4 mm wide, falcate, umbonate above the claw, apex obtuse, base subtruncated on the vexillary margin, sericeous on the central-apical region of the dorsal surface, claw 6.0– 6.1 mm long; staminal tube 9.9–10.0 mm long, submembranaceous, reddish, conspicuously thickened basally, glabrous; anthers 0.5–0.6 mm long, ovoid, glabrous; ovary 7.0– 7.2 mm long, 0.9–1.0 mm wide, lanceolate, slightly curved on the vexillary margin, sericeous except on the central portion; style 6.9–7.0 mm long, glabrous, conspicuously curved; stigma punctiform, stipe 1.4–1.5 mm long, ovules 5, sub-reniform, hypanthium ca. 1 mm long, asymmetrical. Fruit 6.0– 11.3 cm long, 1.2–2.0 cm wide, 1–3-seeded, glabrous, lanceolate, woody, base attenuate, apex obtuse and mucronulate, vexillary margin nerviform, discreetly reticulate, light brown, stipe 0.8–1.0 cm long. Seeds 7.5– 8.2 mm long, 6–7 mm wide, reniform, smooth, elliptic in cross section, light brow, hilum suborbicular, submedial, margin not thickened.

Distribution and ecology: —This species is probably endemic to the states of Bahia and Pernambuco, in the northeastern region of Brazil. In Bahia, it is found in the central part of the state, growing in caatinga vegetation, in rocky outcrops, on clayey soils. In Pernambuco, the species occurs in montane dry forests (“brejos de altitude”; Sales et al. 1998) in the eastern part of the state, at ca 800 m elevation.

Etymology: —The specific epithet nitens refers to the brightness of the leaflets on the adaxial surface.

Phenology: —Flowering in February and fruiting in June.

Relationships and characterization: —This species is morphologically similar to Muellera virgilioides from which it differs by its fruits lanceolate, chartaceous and with superior margin nerviform, bracts and bracteoles without secretory cavities, calyx with triangular vexillary lobe, anthers ovoid and glabrous, ovary glabrous on central portion, beyond seeds reniform, elliptic in cross-section and with orbicular hilum. In M. virgilioides , the fruits are woody, oblong-elliptic to elliptic, conspicuously thickened on the superior margin, and constricted between the seeds, the bracts and bracteoles have secretory cavities, the calyx has rounded vexillary lobes, the anthers are ovate to orbicular and indumented, the ovary is fully indumented, and the seeds are oblong, linear in cross section, and have a elliptic hilum.

Conservation status:—According to IUCN (2001) criteria, the species should be considered “Near Threatened” (NT) because the areas of its occurrence (Caatinga vegetation and montane forests) have been under intense pressure of deforestation for the extraction of timber.

Additional specimens examined (paratypes):— BRAZIL. Bahia: Ipirá , ca. 6 km no ramal ao sul da estrada do feijão na BR 52 , 12º05´S, 40º00´W, 2 February 1993, Queiroz et al. 3125 ( CEPEC, HUEFS, K, NY, UEC) ; Palmeiras, estrada Palmeiras-Vale do Caparão próximo a Rio Preto , 12º31´S, 41º33´W, 900 m, s.d. s.col. ( ALCB 041201 ) . Pernambuco: Floresta, Serra do Umã , 16 May 1971, Heringer et al. 790 ( PEUFR, RB) ; Idem , 29 May 1971, Heringer et al. 941 ( UB) ; Inajá, Reserva Biológica de Serra Negra , 80º36´S, 38º34´15´´W, 9 December 1995, Laurênio et al. 264 ( PEUFR) .

Figures

FIGURE 3. Muellera nitens. 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. R. Schütz et al. 1328; N–O. E.P. Heringer et al. 790)