The results of the first detailed botanical inventory in the region of the Cristalino State Park, Mato Grosso, Brazil, are presented, including an annotated checklist. A total of 1366 species of vascular plants, representing 626 genera and 151 families, were recorded. The most species-diverse families included Leguminosae, Rubiaceae, Melastomataceae, Malvaceae (sens. lat.) and Moraceae. The flora includes at least seven new species and several endemics from the Serra do Cachimbo, as well as many new records for the State of Mato Grosso and several for Brazil. Further studies are likely to increase the number of species significantly. The region does not show high alpha-diversity by Amazonian standards but is ecologically diverse, resulting in high levels of beta-diversity. Considering this biological richness, its situation within the important yet relatively poorly studied ecotone of the Amazonian margin, and its strategic position at the advancing frontier of deforestation pushing northwards into the basin, Cristalino is a high priority for conservation.
floristic; inventory; Amazon; Mato Grosso; Cristalino River; conservation
