Revisão taxonômica das espécies de Virola Aublet (Myristicaceae) do Brasil

Abstract

In this work, the author presents a critical study and revision of the species of Virola Aublet (Myristicaceae) occurring in Brazil, known vernacularly in various regions of the country as "bicuiba", "ucuuba", "urucuba" and, commercially, as "virola". The genus is one of the most important of the american Myristicaceae, not only due to its wealth of species, but also because of the economic and medicinal value that various of its species represent. This work opens with an explanation of why the study was made, followed by an historical sketch of the principal contributions to our knowledge of the genus in Brazil and a brief description of its economic importance. A discussion of the geographic distribution of the genus Virola within Brazil is included, as well as an examination of its morphological, anatomical and palynological aspects. Data on the phenology of a number of principal species, obtained primarily from herbarium material, are presented and discussed. In a more speculative vein, possible generic and evolutionary relationships of Virola are also discussed, based primarily on external morphology, due to the lack of knowledge concerning cytology within the genus. The major portion of this study is devoted to the classification and taxonomic descriptions of the genus and its species. A key for the identification of the neotropical genera of Myristicaceae has been included to show intergeneric relationships and affinities, as well as another key for the species of Virola considered in this revision. The descriptions are accompanied by photographs or original analytical drawings, principally of the leaves, flowers and fruits; in adition, distribution maps for each species have been prepared. A list of the specimens consulted is included at the end of each description. Finally, the author has suplied additional information concerning the common names, uses, phenology and habitat of each species. The groups and sections that have been proposed previously by other botanists are rejected; three binomials are reduced to synonymy; the descriptions of various species are amplified; and the distribution areas of the majority of species are considerably increased. A total of 35 Brazilian species of Virola are recognized as valid in this work.