Raciborskanthos, Genus – synonym of Cleisostoma, Genus
Ranorchis, Genus – synonym of Pterostylis, Genus
Rhachidibulbon, Section (Malaxideae)
Rhamphidia, Genus – synonym of Hetaeria, Genus
Rhizobium, Section (Dendrobium)
Rhizocaulon, Section – synonym of Polymeres, Section (Bulbophyllum)
Rhizophyllum, Section (Phreatia)
Rhodochilus, Section (Calanthe)
Rhynchanthera, Section (Taeniophyllum)
Rhynchanthera, Genus – synonym of Corymborkis, Genus
Rhynchophreatia, Genus – synonym of Thelasis, Genus
Rhytionanthos, Genus – synonym of Bulbophyllum, Genus
Ridleya, Genus – synonym of Thrixspermum, Genus
Ritaia, Genus – synonym of Ceratostylis, Genus
Roptrostemon, Genus – synonym of Nervilia, Genus