Foliar anatomy of Rhynchosia spp. (Leguminosae, Papilionoideae) from Roraima state, northern Brazilian Amazon

ABSTRACT Comparative studies on the structure of foliar anatomy in four species of Rhynchosia from Roraima state (northern Brazilian Amazon) were carried out to identify additional morphological characters to support the definition of the systematic boundaries among the species. Fully expanded leaves, including the petioles, were collected from the upper nodes of a plant’s stem. Anatomical characters were observed in cross-sections of the middle portion of leaflets and petiole segments. Presence and distribution of glandular trichomes, continuity of sclerenchyma around the vascular bundles in leaflet blades and the conformation of the area between the two ridges of petioles were important characters to distinguish among the species of Rhynchosia. For the first time we report a distinct multicellular gland-like structure which we found in the petioles of three species.