XVI International Botanical Congess

The cerrado biome in Brazil covers the central plateaux. In the North- astern border there is a transitional zone between the Cerrado and the Caatinga vegetation. The cerrado consists of savannah types going from grasslands to dense woodlands plus gallery forests and veredas (swampy palm dominated sites). The Caatinga includes dry, thorny, deciduous forests occurring under a semi-arid climate. The objective of this work was to study the floristics of this zone. Four collecting stations were chosen at extremes and intermediate points of the study- rea. Field trips were conducted in the dry and wet seasons for two years. Voucher specimens were deposited at the IBGE Herbarium. A total of 890 species in 445 genera and 113 families were found. The richest families were Leguminosae, Gramineae, Rubiaceae, Compositae, Euphorbiaceae, Melastomataceae, Malpighiaceae, Bignoniaceae, Cyperaceae and Sapindaceae. Ten families, contained 51.7 % of species.