Drosera graomogolensis (Droseraceae), a New Species from the Campos Rupestres of Minas Gerais, Brazil

Abstract

Drosera graomogolensis T. Silva sp. nov. is described from the region of Grao-Mogol, Minas Gerais, Brazil. The species is included in section Drosera and is related to D. villosa A. St. Hilaire. The morphological characters that distinguish it from other species in the section are discussed, together with details of habitat. According to Silva (1994), the genus Drosera in Brazil has a short stem, 0.5-1.0 cm (rarely long); spatulate leaves (rarely linear), with stipules (rarely without); two to many flowers located on cyme inflorescences; a gynoecium with 3 or 5 carpels, with 3 bipartite styles nearly to the base or 5 whole styles, and 5 or 6 lobed, two-lipped, clavate or fimbriate stigmas. The fruits are capsules with 3 or 5 valves, containing numerous seeds with reticulate or papillose testa. In the course of floristic studies of the Brazilian campos rupestres (savanna-like vegetation that occurs at elevations over 600 m in the Brazilian states of Bahia, Goids, and Minas Gerais), collections were made in the municipality of Grao-Mogol, in the northern part of the mountain range known as the Cadeia do Espinhago, State of Minas Gerais. A study of the species in the genus Drosera for the Florula of Grao-Mogol confirmed one species to be distinct from all other known species in the genus in its vegetative and floral characteristics. Drosera graomogolensis T. Silva, sp. nov. TYPE: Brazil. Minas Gerais: Grao-Mogol, C6rrego da Bonita on the way up to the Morro Jambeiro, 7 Sep. 1990, T R. S. Silva et al. CFCR 13506 (holotype, SPF; isotype, RB). Figure 1. Herba 15.0-34.0 cm alta. Caules elongati, 3.0-7.0 cm longi. Folia rosulata, vinacea, matura pendentia, oblonga, 1.5-3.5 cm longa, 3.0-6.0 cm lata. Inforescentiae 1-2, vinaceae, 14.0-31.0 cm longae; flores 10-16; pedunculi 13.5-18.5 cm longi; ovaria 3-carpellaria, ad 5.5 mm longa; styli 3, ad 4.0 mm longi, profunde 2-partiti; stigmata 6, 2-3-lobata. Fructus capsularis, valvis 3; semina obovoidea, reticulata. Herb, 15.0-34.0 cm tall. Stems elongate, 3.07.0 cm long. Leaves wine-red, spreading with age, forming a rosette, oblong, 1.5-3.5 cm long, 3.0-6.0 cm broad, villous on the upper 2/3 of the upper surface, the glandular tentacles radially symmetrical, glabrous on the lower /3, lower surface villous, the trichomes filamentous; stipules rectangular, membranaceous, 2.0-4.0 mm long, 1.5-2.0 mm broad, the laciniae 1.5-2.5 mm long. Inflorescences 1 or 2, wine-red, 14.0-31.0 cm long, bearing glandular trichomes, flowers 10-16; peduncles 13.5-18.5 cm long; bracts wine-red, linear, lower surfaces papillose with glandular trichomes, caducous; pedicels wine-red, 3.0-4.0 mm long; sepals wine-red, 4.06.0 mm long, united near the base, lower surfaces papillose, with glandular trichomes, laciniae oval, ca. 4.5 mm long, 1.5-2.0 mm broad, acute at the tips; petals unguiculate, 7.5-8.0 mm long; stamens ca. 4.0 mm long, anthers ca 1.5 mm long; gynoecium with 3 carpels, ca. 5.5 mm long, styles 3, ca. 4.0 mm long, bipartite nearly to the base; stigmas 6, 2-3-lobed. Fruits with 3 valves; seeds obovoid, testa reticulate. Drosera graomogolensis is characterized by the elongate stems, the leaves that spread with age, the lobed stigma, and the obovoid seeds. The presence of spatulate leaves with petioles not distinct from the blade differentiates D. graomogolensis from D. intermedia Hayne, D. cayennensis Sagot ex Diels, D. communis A. St. Hilaire, D. roraimae (Klotsch ex Diels) Maguire & Laundon, D. capillaris Poiret, and D. brevifolia Pursh, all of which possess evident petioles. Drosera graminifolia A. St. Hilaire has linear leaves, and D. montana A. St. Hilaire has leaves pressed close to the ground, a short stem, and inflorescences with up to 8 flowers. Drosera sessilifolia A. St. Hilaire belongs to section Thelocalyx, which is characterized by possessing a gynoecium with 5 carpels and 5 styles with fimbriate stigmas. Drosera graomogolensis is similar to D. villosa A. St. Hilaire, but the latter has short stems, a bilabiate stigma, and fusiform seeds (Fig. 2), while the leaves are pressed close to the ground. Drosera graomogolensis is placed in subgenus Drosera sect. Drosera (Diels, 1906). Drosera graomogolensis is found in sizable popNovoN 7: 85-87. 1997. This content downloaded from 157.55.39.126 on Mon, 29 May 2017 17:45:35 UTC All use subject to http://about.jstor.org/terms