Abstract. P. Delforge.- Contribution to the knowledge of the Orchids of the department of the Gers (Midi-PyrŽnŽes, France) [Natural. belges 77 (Orchid. 9) (1996): 171-190]. Research in the South-West of France, department of Gers (32), in June 1981, 1995, and 1996 has revealed 25 orchid species, of which 4 seem new for the department: Cephalanthera rubra, Limodorum abortivum, Ophrys aegirtica (sp. nova) and Serapias cordigera. Three interspecific and 2 intergeneric hybrids have also been found. An updated list of species is provided as well as the list of 200 localities prospected.

Key-words: Flora of France, department of Gers (32); Orchidaceae.