Little knowledge has been gathered on ferns and lycophytes occurring in the semi-arid region of Brazil known as the Caatinga, perhaps due to the widespread idea that a semi-arid climate would be incompatible with environmental demands of ferns and lycophytes (high humidity and shade). Ferns and lycophytes are represented in the semi-arid region of Brazil by at least 41 species, 20 genera and 11 families, distributed in the northeastern states (except Maranhão) and Minas Gerais. In this region, most of the species were recorded in moist, shaded microhabitats: cracks in rocks, ravines in shaded areas, springs, temporary lakes or areas with temporarily flooded soil. Although the majority of species recorded are widely distributed throughout Brazil, the high representation of aquatic species and low representation of epiphytes demonstrate the unique identity of the fern and lycophyte flora of the semi-arid region.
Caatinga; pteridophytes; flora; Northeastern Brazil
