The semiarid region of Rio Grande do Norte State in the Northeast region of Brazil can be divided into two main geoenvironmental units: Sertaneja Depression and Potiguar Sedimentary Basin. Although the flora of sandy sedimentary basins is usually different from that of crystalline terrains, part of the Potiguar Basin has stony paleo-alluvial deposits, with rolled pebbles, imposing different edaphic conditions t...