With the purpose to contribute to the knowledge of the phytophysionomy of transition in a area in Campo Maior province, recover for a vegetation denominated Complex of Campo Maior, utilized the Quadrants Method considering all stem diameter of > 3cm at the soil level. They were allocated 100 points in each area, Alto do Comandante and Baixão da Cobra, located in Lourdes' Farm. Were showed 46 species in Alto do Comandante and 44 in Baixão da Cobra, in a total of 68 species. The density values and of basal area were 2,730 and 2,799ind ha-1 and 38.22 and 38.58m² ha-1, respectively. The species with major rate of importance value (IVI) in Alto do Comandante were Casearia ulmifolia Vahl. ex Vent., Aspidosperma subincanum Mart., Combretum leprosum Mart. and Bauhinia ungulata L. The first position of C. ulmifolia was in consequence of three relative parameter. Only three species of major IVIs contributed with the majors rate of covering value (IVC). In Baixão da Cobra, the specie of major IVI was Aspidosperma subincanum Mart, also in consequence of three relative parameters values. Combretum mellifluum Eichler, Bauhinia pulchella Benth. and Buchenavia capitata (Vahl.) Mart. also stood out. The four species with major IVI corresponded with that ones of major IVC. The rates of diversity of Shannon (H') was 3.20 and 3.09nats ind-1 to Alto do Comandante and Baixão da Cobra, this values can be considered high when compared with the values found in works developed an Caatinga, Carrasco and Cerrado Brazilian Northeast.
phytosociology; ecotone; Campo Maior; Piaui State; Brazil
