Anatomia foliar de espécies de Pleroma D. Don ‘linhagem Svitramia’ (Melastomataceae): Implicações taxonômicas e xeromorfia

Abstract

Pleroma “Svitramia lineage” includes endemic Cerrado species occuring in a rupestrians fields in Minas Gerais, Brazil. Its species are recognized by the presence of a persistent calyx and anther without pedoconectivo among the others of the genus, with anatomical descriptions non-existent for vegetative organs. Therefore, here we present anatomical descriptions of the leaves of the eight species of Pleroma “Svitramia lineage”. Plant material was collected in Cerrado areas in the Serra da Canastra National Park, Minas Gerais, Brazil. Samples of P. bandeirae, P. canastrense, P. gertii P. integerrimum, P. minus P. petiolatum, P. viscosa and P. wurdackianum were processed and analyzed according to usual techniques light microscopy and scanning electron microscopy protocols. Leaves presents claviforms trichomes, non-glandular and glandular emergences and distinct patterns of epicuticular waxes, dorsiventral and isobilateral mesophyll, and vascular system with collateral vascular bundles in leaf blade, and bicollateral in midrib and petiole. P. petiolatum is the only one in the lineage that has a petiole. The anatomical diversity of Pleroma “Svitramia lineage” was correlated to taxonomic implications and to xeromorphy.