The palm community in a forest of central Amazonia clearly shows three zones according to the hydromorphic condition of the soil: well-drained soils of the upland forest, poorly-drained soils of a transition zone, and water-logged soils of the seasonal swamp forest. The community is remarkable in three aspects: its size (with 2122 palms/ha, and the highest density on water-logged soils); its great diversity (32 species/1.2 ha), which also depends on the hydromorphic condition of the soil; and its variety of biological forms with characteristic acaulescent palms in the understory, monocaulous and multiple-stemmed palms in the upper understory, and arborescent palms only reaching the canopy in the seasonal swamp forest. PALMS ARE AN ABUNDANT and characteristic component of the forests of central Amazonia. They are found in all levels of the forest, from the understory to the canopy, on all soils and topographic sites, and exhibit a variety of growth forms. However, as Moore (1973a) lamented, our ignorance of the biology and ecology of palms is almost complete. Corner's marvelous book (1966) represents the cornerstone of our knowledge of the family in these ways. Several early works dealt specifically with the palm flora of Amazonia. In fact, since the early studies of this subject (Poiteau's (1822) history of palms in French Guiana; Wallace's famous book (1853); Spruce's works (1871, 1908); the numerous publications of Martius (18231853)3, Drude (1876-1908)3, Barbosa-Rodrigues (18751907)3, and Burret (1928-1956)3, only Macbride's work (1960) in Peru and Wessels-Boer's (1965) and (1971) in Suriname and Venezuela, respectively, have contributed significantly to the taxonomy of amazonian palms. Recently, Balick and de Silva (1982) established the state of systematic collections in regional herbaria and showed the necessity to intensify them. Works relating to the ecology of palms are even rarer (see Discussion). Thus, we initiated a series of ecological investigations on Amazonian palms in 1980 at the National Institute for Amazonian Research (INPA). This paper presents a community-level study of palms in central Amazonia and describes the distribution and abundance of the most important species in relation to topography and soils.