• Species and lower taxa
• Higher taxa
• Common names

Macdonaldia, Genus – synonym of Thelymitra, Genus

Macodes, Genus

Macrobulbon, Section – synonym of Beccariana, Section (Bulbophyllum)

Macrocentrum, Genus – synonym of Habenaria, Genus

Macrolepis, Genus – synonym of Bulbophyllum, Genus

Macrostylidia, Section – synonym of Brachyantha, Section (Bulbophyllum)

Macrostylis, Genus – synonym of Corymborkis, Genus

Macrotis, Genus – synonym of Ceratostylis, Genus

Macrouris, Section (Bulbophyllum)

Macrura, Genus – synonym of Habenaria, Genus

Malachadenia, Genus – synonym of Bulbophyllum, Genus

Malaxideae, Tribe

Malaxis, Genus

Malleola, Genus

Manobulbon, Section – synonym of Uncifera, Section (Bulbophyllum)

Mariarisqueta, Genus – synonym of Cheirostylis, Genus

Mastigion, Genus – synonym of Bulbophyllum, Genus

Mastigion, Genus – synonym of Cirrhopetalum, Section (Bulbophyllum)

Mecosa, Section (Platanthera)

Mecosa, Genus – synonym of Platanthera, Genus

Mediocalcar, Genus

Medusorchis, Genus – synonym of Habenaria, Genus

Megaclinium, Genus – synonym of Bulbophyllum, Genus

Megaloglossum, Section – synonym of Polymeres, Section (Bulbophyllum)

Menephora, Genus – synonym of Paphiopedilum, Genus

Mesicera, Genus – synonym of Habenaria, Genus

Mesoclastes, Genus – synonym of Luisia, Genus

Mesodactylis, Genus – synonym of Apostasia, Genus

Mesoptera, Genus – synonym of Liparis, Genus

Metachilum, Genus – synonym of Appendicula, Genus

Microbulbon, Section – synonym of Brachyantha, Section (Bulbophyllum)

Micromonanthe, Section – synonym of Polymeres, Section (Bulbophyllum)

Micropera, Genus

Microphytanthe, Section (Dendrobium)

Microstylis, Genus

Microstylis, Genus – synonym of Malaxis, Genus

Microtatorchis, Section (Aeridinae)

Microtatorchis, Genus

Minahassaea, Section – synonym of Stachysanthes, Section (Bulbophyllum)

Minutissima, Section (Bulbophyllum)

Mischobulbum, Genus

Mitopetalum, Genus – synonym of Tainia, Genus

Moerenhoutia, Genus

Molloybas, Genus – synonym of Corybas, Genus

Monanthaparva, Section (Bulbophyllum)

Monanthes, Section (Bulbophyllum)

Monanthes, Section – synonym of Monanthes, Section (Bulbophyllum)

Monanthochilus, Genus – synonym of Sarcochilus, Genus

Monochilus, Section (Zeuxine)

Monochilus, Genus – synonym of Zeuxine, Genus

Monorchis, Genus – synonym of Herminium, Genus

Monosepalum, Section (Bulbophyllum)

Monosepalum, Genus

Monosepalum, Genus – synonym of Bulbophyllum, Genus

Monosepalum, Genus – synonym of Monosepalum, Section (Bulbophyllum)

Montolivaea, Genus – synonym of Habenaria, Genus

Monustes, Genus – synonym of Spiranthes, Genus

Muluorchis, Genus – synonym of Tropidia, Genus

Mycaranthes, Section (Eria)

Mycaranthes, Genus – synonym of Eria, Genus

Myrmechis, Genus

Myrobroma, Genus – synonym of Vanilla, Genus