Abstract
The floral development of 47 epidendroid and vandoid orchids was studied by means of scanning electron microscopy, paying special attention to the early development of the gynostemium (column) and its appendages. The following main conclusions are drawn: the lateral appendages of the adult gynostemium are homologous with the two lateral stamens of the inner whorl; their primordia are present even in species which lack prominent appendages in the adult gynostemium (incorporation of the sta‐minodial primordia into the gynostemium during development). Ventral appendages observed in some species are supposed to be vestiges of the adaxial stamens on account of their early initiation. It is confirmed that the rostellum is the upper part of the median stigma lobe and that the lip corresponds to the inner median tepal. The affinities of the epidendroid and vandoid orchids are briefly discussed.

This publication has 13 references indexed in Scilit: