Developmental studies in orchid flowers III: Neottioid species

The floral development of 19 species of Neottioideae (sensu Rasmussen 1985) was studied by means of scanning electron microscopy, paying special attention to the early differentiation of the organs that constitute the gynostemium. The gynostemium development of the Epipactieae proved to be similar to that of the Epidendroi deae and Vandoideae, in particular in that massive primordia corresponding to inner lateral staminodes are differentiated in early stages and later constitute the lateral appendages of the gynostemium. In the Neottieae a progressive reduction and delayed initiation of these staminodes was observed: the lateral teeth of the gynostemium originate from large staminode primordia in one species ( Corymborkis veratrifolia ), in the remaining species they are initiated in later stages or are missing.