Contribuição ao conhecimento das Gnetáceas da Amazônia (Gimnospermas)

Abstract

In the present contribution, the author updates the geographic distribution of the six species of the genus Gnetum in the Amazonian region, based on field observations and material of the herbaria INPA, MG and IAN. Some unusual distribution patterns are pointed out for each species. G. paniculatum and G. schwackeanum are restricted to the State of Amazonas and G. urens to Pará. G. nodiflorum is dispersed to the north of the region and less common G. leyboldii is found more to the south. G. venosum is distributed from the estuary, in Pará, up to Manaus. The different kinds of habitats of the species are also discussed, as well as, their economic importance. The taxonomy is treated in species descriptions and a key to identify them. It is suggested that a careful study, based on good and abundant material, would probably reduce the number of species because of the apparent small amount of interspecific variation between some species, presently recognized.