O Gênero Marlierea cambess. (Myrtaceae) na Amazônia Brasileira.

Abstract

Myrtaceae Adans., one of the larger and most taxonomically difficult dicotyledonous families, is comprised of about 100 genera and 3,500 species occurring primarily in tropical America and Austrália. Approximately 1,000 species occur in Brazil, about half of which lack modern taxonomic treatment. A morphological study of Marlierea Cambess. occurring in Amazonian Brazil was carried out in order to obtain a better understanding of the morphology and taxonomy of ali species in the region and to provide data to elucidate the taxonomic segregation of Marlierea from the morphologically similar Myrcia DC. ex Guill. Although it was not possible to examine type specimens, only specimens were examined which had been previously identified by Myrtaceae family specialists. In Amazonian Brazil, Marlierea is represented by 11, primarily forest, species {Marlierea bipennis (O. Berg) McVaugh, M. caudata McVaugh, M. ensiformis McVaugh, M. ferruglnea (Poir.) McVaugh, M. mcvaughii B. Holst, M. scytophylla Diels, M. spruceana O. Berg, M. subulata McVaugh, M. summa McVaugh, M. umbratlcola (Kunth) O. Berg, and M. velutina McVaugh). The taxonomically problematic M. obumbrans (O. Berg) Nied. is discussed as a badly knew species. The species are trees cr shrubs with leaves opposite (sometimes alternate in M. velutina)] inflorescences racemose cr paniculate (in panicles, cymes, cr dichasiums), sometimes in fasicles; flower buds generally closed; calyx lobes 4-5, opening irregularly; and petals frequently absent. The states of Amazonas and Pará are the most species-hch. Marlierea spruceana and M. umbratlcola are the most common species, whereas M. bipennis, M. ensiformis, and M. mcvaughii appear to be rare as only one specimen of each, ali from the state of Amazonas, has been collected and deposited in the Museu Paraense Emílio Goeldi herbahum. Marlierea scytophylla occurs primarily in Pará and M. velutina primarily in the state of Rondônia. Additional studies of M. obumbrans, morphologically intermediate between Marlierea and Myrcia, will be untaken in the future in order to establish the correct taxonomic placement of this enigmatic species.