Anatomy and ultrastructure of spur nectary of Gymnadenia conopsea (L.) Orchidaceae

The anatomy and the ultrastructure of spur nectaries of Cymnadenia conopsea at different developmental stages were investigated. The secretory epidermis surrounded the inside of spur and formed many unicellular papillae, which significantly enlarged the secretory surface. At the activity stage the epidermal cells contained characteristic plastids with well developed intraplastidal membrane system and numerous osmiophillic globules. The contact of plastids and endoplasmic reticulum indicates a possibility of the involvement of these structures in the secretory processes. The cell wall and the cuticle did not form a barrier for the secreted nectar and no pores or cracks were visible in the cuticle covering secretory papillae