Ultrastructural Aspects of the Nectary Spur of Limodorum abortivum (L) Sw. (Orchidaceae)

Abstract

The ultrastructure of the nectary spur of Limodorum abortivum (L) Sw. was examined before and after anthesis. In cross section the nectary spur shows an internal epidermal layer of thin-walled cells bordering the secretory cavity and 10–12 layers of parenchyma cells. The ultrastructure of the secretory cells suggests the involvement of ER, Golgi and plastids in nectar secretion. The nectar accumulated in the sub-cuticular space is released into the nectariferous cavity by rupture of the outer layer of the cuticle.