Characters of leaf epidermis in Solanum (clade Brevantherum) species from Atlantic Forest of Northeastern Brazil

摘要

Solanum is the richest and most diverse genus of the Solanaceae and one of the largest among angiosperms. The high number of species in the genus and the morphological plasticity of vegetative organs make the taxonomy of the group quite complex. We carried out an anatomical study of the leaf epidermis of six species of the Brevantherum Clade occurring in the Atlantic Forest of Northeastern Brazil (Solanum asperum, Sol anum maranguapense, Solanum anisocladum, Solanum rugosum, Solanum stipulaceum and Solanum swartzianum), in order to support their taxonomy. Analyses were performed by the usual techniques for leaf anatomy, followed by light and scanning electron microscopy. All species showed leaf epidermis cells with sinuous anticlinal walls, and anisocytic stomata. Anomocytic stomata were also observed in S. asperum, S. anisocladum and S. swartzianum. Except for S. stipulaceum with amphistomatic leaves, the hypostomatic pattern was predominant. A great diversity of stellate trichomes was observed, mainly porrect-stellate and multiangulate, and peltate trichomes were only observed in S. swartzianum. The characters of leaf epidermis and its annexes, mainly the morphology of trichomes, are useful in distinguishing the Solanum species (clade Brevantherum) from Northeastern Brazil