Contents: Abbreviations,Preface,Acknowledgement,Introduction,General,Morpho-taxonomical,Ecological and anatomical,Material and methods observations,Subfamily cypripedioideae,Tribe cypriedioideae,Subfamily orchidoideae,Tribe neottieae,Tribe orchidae, Tribe eppidendreae, Discussion, General anatomical feartures,Anatomy in relation to ecological,Adaptability of orchids,Impact of anatomy on classification,Summary,Conclusions,Literature cited,Orchids in ancient Indian literature,Medicinal value of the orchids endangered orchids.