Contribuição à taxonomia de myclaria o. berg (myrtaceae) na Amazônia brasileira

Abstract

Myrtateae Adans. is composed of about 100 genera and 3500 species, being Australia and Central and South America, the main centers of distribution of its species. This taxon is among the largest and most complex groups of plants in the New World. In Brazil, the Myrtaceae present about 1000 species, distributed especially in the Amazon rainforest and Atlantic forest. Among the little studied genera of this family is Myrciaria O. Berg, with a neotropical distribution, occurring from Mexico to Uruguay. In the Brazilian Amazon, the exact number of its representatives is still controversial, with an estimated 9 to 13 species. There is no recent taxonomic treatment on the Amazonian species of this genus. Therefore, this study aims to update the data on the morphology and taxonomy of Myrciaria, based on the collections deposited in the Herbaria IAN, INPA and MG, aiming at an update of the number of its species as well as their relationship with related groups. The study methods were those traditional in plant taxonomy, such as dissection, morphological analysis, description and illustration of the herborized samples. Seven (7) species from the region were studied: Myrciaria amazonica O. Berg, M. dubia (Kunth) McVaugh, M. f/oribunda (H. West ex Willd.) O. Berg, M. /anceo/ata O. Berg, Myrciaria tenella (OC.) O. Berg, M. spruceana O. Berg and M. vismeifo/ia (Benth.) O. Berg. It is believed that four (4) more species occur, but they will be treated in a next stage, since the available material was not yet sufficient to better define them: Myrciaria sp.I, Myrciaria sp.ll, Myrciaria sp.11I and Myrciaria sp.IV. The Myrciaria are shrubs to trees, with opposite leaves, axillary inflorescences with or without developed central axis, 4-6-flowered, the flowers tetramerous, calyx circumcised at the base of the hypanthium, deciduous after anthesis, petals 4; ovary bilocular, ovules 2 per loculus; fruit berry, 1-3 seminate, with circular scar, indicating the fall of the calyx; seeds with invaginated type embryo and sold cotyledons, without evident radicle. The species were illustrated and an identification key was prepared.