Floral anatomy and ultrastructure in Lepanthes calodictyon group

Background : Previous studies revealed that ultrastructure and histochemistry of the flowers give insight to pollination mechanism of the orchid species. The microscopic features of species within Pleurothallidine subtribe is poorly understood. In this study we investigated three Lepanthes species: L. calodictyon , L. saltatrix and L. tentaculata . All of them represent similar flower morphology, distinct from the other representative of the genus. Results : Our analyses revealed presence of features usually associated with myophily. Papillae of lips and petals of the Lepanthes calodictyon group, were rich in lipids and proteins, what was correlated with high metabolic activity. Furthermore, ultrastructural and morphological features are similar to those observed in other fragrance emitting orchid species. Conclusions : Histochemical, ultrastructural and morphological features of the papillae on the surface of the lip and petals of examined taxa indicate that papillae are in fact osmophores.