The structure of nectary of Platanthera bifolia L. Orchidaceae

Abstract

The anatomy and ultrastructure of floral nectary of Platanthera bifolia were studied. The epidermis inside the nectary spur showed characteristic features of secretory tissue. Many cells of this epidermis were protruded forming unicellular hairs. The protoplasts of secretory cells were characterized by few small vacuoles, a lot of mitochondria and leucoplasts, which stored starch before secretion. Numerous vesicles budded off from the endoplasmic reticulum and the Golgi apparatus were accumulated near plasmalemma and fused with it. This fact probably indicates that these structures are involved in secretory processes. Nectar was released onto the surface through the pores in a ruptured cuticle, which covered the walls of secretory hairs.