Application of NAA to Cymbidium stigmas induces anthocyanin formation in columns and labella as well as swelling of the former, stigmatic closure, and wilting of sepals and petals. All of these are aspects of post‐pollination behavior by orchid flowers. Anthocyanin formation and wilting, but not swelling of the column and stigmatic closure, can be inhibited by actinomycin D, ethionine and puromycin. This suggests that anthocyanin formation and wilting require de novo DNA‐dependent RNA synthesis and production of new proteins. Swelling of the column and stigmatic closure, on the other hand, are apparently independent of such new synthesis and may be brought about by the activation of pre‐existing compounds.