A floristic and phytosociological survey was conducted in a caatinga area in the Agreste (sub-humid) region of Paraíba state. All trees and shrubs <FONT FACE=Symbol>³</FONT> taller than 1m and larger than <FONT FACE=Symbol>³</FONT> 3cm stem diameter found in 30 plots, 10x20m each, were identified and measured. Standing dead plants were also included. A total of 1952 plants were registered, belonging to 22 families, 38 genera and 54 species. Families with most species were Mimosaceae (6 species), Euphorbiaceae (6), Caesalpiniaceae (5), and Rubiaceae (5). Total plant density and stem basal area were 3253 plant ha-1 and 34.77m² ha-1. Maximum diameter and height were 63cm and 15m. About half of the plants (45.7%) had a stem diameter between 3 and 6cm. Thiloa glaucocarpa (Mart.) Eichl. was the most important species (highest IVI value). The flora included mostly species already registered in other caatinga areas but also species which are typical from more mesic formations, specially the humid forests of high altitudes in Northeast Brazil.
Phytosociology; agreste; Paraíba; floristic composition; dry forests