Dactylorhynchus, Genus – synonym of Bulbophyllum, Genus
Dactylorhynchus, Genus – synonym of Pelma, Section (Bulbophyllum)
Decaisnea, Genus – synonym of Tropidia, Genus
Dendrobium, Section (Dendrobium)
Dendrocolla, Section (Thrixspermum)
Dendrocolla, Genus – synonym of Thrixspermum, Genus
Dendrolirium, Genus – synonym of Eria, Genus
Diadochanthe, Section – synonym of Stachysanthes, Section (Bulbophyllum)
Dialeipanthe, Section – synonym of Intervallatae, Section (Bulbophyllum)
Diceras, Section – synonym of Uncifera, Section (Bulbophyllum)
Dicerostylis, Genus – synonym of Hylophila, Genus
Didactyle, Genus – synonym of Bulbophyllum, Genus
Dienia, Genus – synonym of Malaxis, Genus
Digomphotis, Genus – synonym of Peristylus, Genus
Dilochiopsis, Genus – synonym of Eria, Genus
Dipera, Genus – synonym of Disperis, Genus
Diphyes, Genus – synonym of Bulbophyllum, Genus
Diphyes, Genus – synonym of Monanthes, Section (Bulbophyllum)
Diplanthera, Genus – synonym of Platanthera, Genus
Diplectraden, Genus – synonym of Habenaria, Genus
Diploconchium, Genus – synonym of Agrostophyllum, Genus
Diplodium, Genus – synonym of Pterostylis, Genus
Diptychanthes, Section – synonym of Stachysanthes, Section (Bulbophyllum)
Dissorhynchium, Genus – synonym of Habenaria, Genus
Distichae, Section (Malaxideae)
Distichis, Genus – synonym of Liparis, Genus
Disticholiparis, Genus – synonym of Liparis, Genus
Distichophyllae, Section (Dendrobium)
Diteilis, Genus – synonym of Liparis, Genus
Dolichodesme, Section (Agrostophyllum)
Donacopsis, Genus – synonym of Arundina, Genus
Drymoda, Genus – synonym of Bulbophyllum, Genus
Dryopeia, Genus – synonym of Disperis, Genus
Dryorkis, Genus – synonym of Disperis, Genus