Osmophores of the fragrant orchid Gymnadenia conopsea L. (Orchidaceae)

Abstract

Osmophores of Gymnadenia conopsea are located on the adaxial surface of labellum and on distal parts of two lateral sepals. Osmophore cells are characterised with a large nucleus, and dense, granular cytoplasm, which contains numerous membranes of ER and large lipid droplets. Plastids are probably involved in the synthesis of fragrant substances and, contrary to the most of investigated orchid species, they do not contain starch. Numerous secretory vesicles take part in the secretion. Secreted fragrant substance migrates across the cell wall and through the pores in the cuticle. It is not accumulated on the osmophore cell surface.