Ibidium, Genus – synonym of Spiranthes, Genus
Ichtyostomum, Genus – synonym of Bulbophyllum, Genus
Iebine, Genus – synonym of Liparis, Genus
Imitatores, Section (Bulbophyllum)
Intervallatae, Section (Bulbophyllum)
Ione, Genus – synonym of Bulbophyllum, Genus
Iridorchis, Genus – synonym of Cymbidium, Genus
Iridorchis, Genus – synonym of Oberonia, Genus
Iridorkis, Genus – synonym of Oberonia, Genus
Ischnocentrum, Genus – synonym of Glomera, Genus
Ischnopus, Section – synonym of Macrouris, Section (Bulbophyllum)
Itaculumia, Genus – synonym of Habenaria, Genus