NEW APPROACHES IN THE FERN GENUS PTERIS (PTERIDACEAE) FROM BRAZIL.

Background and aims: Pteris is widely distributed with ca. 65 species in the Tropics. In Brazil, 24 species were recognized and five of them are endemic to the Atlantic Forest. The objective of the present paper is to re-evaluate the taxonomy of Pteris occurring in Brazil, based on new morphological evidence of old and recent specimens deposited in herbaria, analysis of types, and observations in the field. M&M: The new approaches are based on morphological data such as SEM images of the spores and from the examination of herbarium collections mainly from SP and RB Herbaria. Results: Four species are being recognized in the present paper (P. lata, P. organensis, P. praealta, and P. sericea). For two of them, two new combinations into Pteris are presented: P. organensis and P. praealta. A key to distinguishing the newly recognized species and its relative taxa, as well as descriptions, illustrations, and comments are presented in this paper. Conclusions: By reviewing herbarium materials, mainly observing the morphology of the spores, and collecting more specimens in the field, it was possible to recognize three species (Pteris lata, P. organensis, and P. praealta) in Brazil and also verify the correct application of the name Pteris sericea to the Brazilian plants. All these names had been previously synonymized in previous studies. After this study, 27 species of Pteris are recognized in Brazil. [ABSTRACT FROM AUTHOR]