A New Species of Miconia (Melastomataceae) from Serra da Canastra National Park, Minas Gerais, Brazil

Abstract

A new species of the genus Miconia sect. Cremanium from highland campo rupestre vegetation of the Serra da Canastra National Park, Sao Roque de Minas, is described and illustrated. It is distinguished from other species in this section by the 4-celled ovary with glabrous apex and leaves lanate below. This new species of Miconia was discovered during a floristic survey carried out by the Herbarium Uberlandense (HUFU) from the Universidade Federal of Uberlandia in the Serra da Canastra National Park, southwestern Minas Gerais state. Miconia angelana R. Romero & R. Goldenberg, sp. nov. TYPE: Brazil. Minas Gerais: Sao Roque de Minas, Parque Nacional da Serra da Canastra, vale da nascente do rio Sio Francisco, lado das matas, beira do c6rrego, 1100 m, 46?15'-47000'W, 20o00'-20o30'S, 20 Nov. 1996, R. Romero & J. N. Nakajima 3773 (holotype, HUFU; isotypes, K, MO, RB, UEC, US). Figures 1-5. Arbor parva ca. 2 m. Lamina oblongo-lanceolata, apice acuto vel acuminato, basi rotundata, margine remote undulato-denticulato, subtus dense lanato. Panicula elongata; flores 5-meri, sessiles, ramis inflorescentiae in glomerulo denso verticillato-congestis. Antherae oblongae vel cuneatae, ad apicem truncatae, 2-porosae. Ovarium 4-loculare, apice glabro. Small tree, ca. 2 m tall, the stem, branches, petioles, lower leaf surface, inflorescence, and hypanthium densely covered with dendritic hairs with long and slender arms, canescent to yellowish brown; young branches slightly flattened, older branches terete and striate. Petioles 1.2-2.2 cm long, striate; leaf blade 5.5-14.0 x 1.5-4.0 cm, oblong-lanceolate, apex acute to shortly acuminate, base narrowly rounded, margin slightly and remotely denticulate, hyaline, above covered with dendritic hairs, soon becoming glabrous, 3-nerved, with an additional tenuous marginal pair, below with the primaries, secondaries, and transverse veins prominent, impressed above. Panicle 7.513.5 cm long, the sessile, 5-merous flowers capitate-congested on very short lateral branchlets; bracts 0.6-1.0 cm long, linear, bracteoles 3.0-3.5 mm long, linear, persistent. Hypanthium 2.3-3.0 x 2.5-3.3 mm, campanulate. Calyx lobes 0.8-1.4 mm long, triangular, apex acute to rounded, external teeth inconspicuous and hidden by the indument. Petals 2.0-2.5 x 1.8-2.0 mm, obovate, apex retuse and asymmetrical, margins and abaxial side papillose. Stamens 10, subisomorphic; filaments 2.0-2.3 mm long, geniculate, glabrous; connective dorsally thickened and prolonged 0.3-0.6 mm below the thecae, with two ventral short lobes and one dorsal short spur; anthers 1.3-1.6 mm long, oblong to cuneate with truncate apex, biporose. Ovary 1.2 mm long, lower half adherent to the hypanthium, 4-locular, apex elongated, papillose, glabrous, 2-3 ovules per locule; style 3.5-4.0 mm long, filiform, glabrous, stigma truncate. Berry 2.5-3.0 x 3.0-3.5 mm, globose, blackish, surface smooth and glabrescent. Seeds 1.2-1.7 mm long, 10-15 per fruit, narrowly to broadly ovoid, surface smooth. This species grows on the margins of small rivers in rocky soil of the highlands of the Rio Sao Francisco headwaters; it was collected with flowers in November, with fruits in December. The section Cremanium Bentham & Hooker, which has eight species in Brazil, occurs mainly in the southeastern region. The new species is placed in this section based on the presence of cuneate and biporose anthers (Cogniaux, 1891). The 4celled ovary with glabrous apex, seeds 1-1.7 mm long, and leaves lanate below distinguish M. angelana from M. hyemalis A. St. Hilaire & Naudin ex Naudin, to which it is certainly most closely related. The latter differs in having a 3-celled ovary with a stellate puberulent apex, longer seeds (22.6 mm), and leaves stellulate-tomentose below. Miconia angelana also resembles M. lymanii Wurdack, endemic to Santa Catarina (Wurdack, 1962), which has a 3-celled ovary with puberulous apex and leaves stellulate-furfuraceous below. The specific epithet was chosen in honor of AnNOVON 9: 98-100. 1999. This content downloaded from 157.55.39.223 on Wed, 24 Aug 2016 05:41:08 UTC All use subject to http://about.jstor.org/terms Volume 9, Number 1 1999 Romero & Goldenberg Miconia angelana from Brazil 99