Taxonomic studies in Cambessedesia DC. (Melastomataceae) / Estudos taxonomicos em Cambessedesia DC. (Melastomataceae)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

A taxonomic re-evaluation of the genus Cambessedesia DC. is conducted, including identification key for all taxa, descriptions, synonymies, list of examined materials, comments about taxonomic affinities based on morphological traits, observations on habitat and distribution, as well as illustrations and distribution maps for all analyzed species. The studies were based on the analysis of 3.000 exsiccatae from 17 national herbaria and 17 herbaria of foreign countries, which was associated with diverse field observations and with inedited scanning electron microscopy examinations of seeds, trichomes, emergencies and stamens. A total of 27 species were identified and two of them were recognized as new The following infrageneric and infraspecific modifications were derived from the taxonomic re-evaluation: Cambessedesia sect. Cambessedesia and Cambessedesia sect. Pyramia are considered synonymies; the epithet C. hilariana was replaced by the epithet fasciculata, because of its priority; C. arenaria and C. tiradentensis were considered synonym of C. corymbosa and C. espora subsp. ilicifolia synonym of C. espora; C. longifolia and C. bahiana were elevated to the specific status. A total of 13 lectotypes and four neotypes were designated. The genus Cambessedesia is characterized by species with opposite leaves, frequently with additional axillary leaves that are small and arranged in brachiblasts, occasionally fasciculate, or verticillate in C. weddellii only. The flowers are 5-(6-) merous with bicolor petals that are red-orange colored and have a yellow base, or that are monochromatic yellow or white-yellowish; stamens 10(-12), 5 in C. semidecandra, and the anther connective is dorsally thickened, often with a calcar at the base, without ventral appendages. The capsules contain oval-depressed seeds that are densely or sparsely tuberculate and, almost always, the anti-raphe is more developed than the raphe. Cambessedesia is endemic to Brazil, where three general patterns of geographic distribution were identified for its species: widely distributed, endemic (Espinhaço Mountains (MG), Chapada Diamantina (BA) and Chapada dos Veadeiros (GO) and disjunct Among the 27 identified species, only C. fasciculata and C. espora are widely distributed. The data in the present work contributes to further understand the systematic of Cambessedesia and are potentially useful for future phylogenetic in this genus.

ASSUNTO(S)

melastomataceae cambessedesia cambessedesia endemic plants plants systematics plantas endemicas campos rupestres melastomataceae taxonomia vegetal

ACESSO AO ARTIGO

Documentos Relacionados