ABSTRACT
A floristic survey of angiosperm species were performed in a gallery forest along the course of the Mandassaia River (an affluent of the Santo Antônio River) in the Municipality of Lençóis, Chapada Diamantina, Bahia State, Brazil (12º33'S x 41º25'W). We intended to describe the flora and examine the potential role of altitude and geographical distance on the flora composition, comparing results with previous surveys of gallery forests at different locations at the same major watershed. The floristic survey identified 116 species, belonging to 96 genera and 51 families. The families with the greatest species richness were Melastomataceae, Fabaceae, Orchidaceae, Asteraceae, Myrtaceae, Euphorbiaceae, and Apocynaceae. Similarity analyses between the arboreal components of the gallery forest of the Mandassaia River and other gallery forests previously examined within the Santo Antonio basin indicated that geographical distance was the most important factor, as closer areas had close similarity values regardless of their altitude. Indicator species for the riparian forests of the Santo Antônio River basin in the Chapada Diamantina include Alchornea triplinervia, Clusia nemorosa, Simarouba amara, Tapirira guianensis, and Vochysia pyramidalis.
Key words:
floristic; Chapada Diamantina; gallery forest