Nectary morphology of Leguminosae senso lato in areas of dry seasonal forest in Brazil

Abstract

Extrafloral nectaries (Efns) are nectar secreting glands found in many species of Angiosperms, including Leguminosae. These structures have various forms (elevated, embedded; stalk present or not; different colors) and positions on the plants (on the rachis, on the petiole), and these characteristics are relevant to taxonomy and morphology studies. This work analyses the morphological diversity of Efns in Leguminosae from a priority conservation area of caatinga in Pernambuco state. The 35 Leguminosae species studied were collected in Mirandiba municipality, a semi-arid region of Pernambuco and submitted to the usual techniques of anatomy and morphology analyses. Among these species, Efns with primary (non-substitutive) and secondary (substitutive) origin were characterized. Two different kinds and eleven distinct Efns forms were found. A large variety of placement, color, shape, and size are reported here. An identification key and illustrations are also provided. Our data increased the number of species studied with Efns in the family, and also confirm the taxonomic and ecological importance of this structure for legumes from the semi-arid region of Brazil.