.
| Genus | |
|---|---|
| Macadamia F.Muell. | |
|   | Macbridea Elliott ex Nutt. | 
| Machairophyllum Schwantes | |
|   | Mackaya Harv. | 
|   | Mackinlaya F.Muell. | 
|   | Macleaya R.Br. | 
|   | Maclura Nutt. | 
|   | Macrocarpaea (Griseb.) Gilg | 
|   | Macrozamia Miq. | 
| Maerua Forssk. | |
|   | Maesa Forssk. | 
|   | Magnolia Plum. ex L. | 
|   | Maianthemum F.H.Wigg. | 
| Maierocactus E.C.Rost | |
|  | Maihuenia (Phil. ex F.A.C. Weber) K. Schum. | 
|  | Maihueniopsis Speg. | 
| Maireana Moq. | |
|   | Malachra L. | 
| Malagasia L.A.S.Johnson & B.G.Briggs | |
|   | Malephora N.E.Br | 
| Malotigena Niederle | |
|   | Malva Tourn. ex L. | 
|  | Mammillaria Haw. | 
|  | Mandragora L. | 
| Manekia Trel. | |
| Mangenotiella M.Schmid | |
|   | Manihot Mill. | 
| Mankyua B.Y.Sun, M.H.Kim & C.H.Kim | |
|   | Mannia Corda | 
|   | Mapania Aubl. | 
| Marattia Sw. | |
|   | Marcgravia Lour. | 
|   | Marchantia L. | 
|   | Marlothistella Schwantes | 
|   | Marrubium L. | 
|   | Marsdenia R.Br. | 
|   | Marshallia Schreb. | 
|   | Martellidendron (Martelli) Callm. & Chassot | 
|   | Massonia Thunb. ex Houtt. | 
| Mastixiodendron Melch. | |
|   | Matelea Aubl. | 
|   | Mathiasella Constance & C.L.Hitchc. | 
|   | Matonia R.Br. ex Wall. | 
|   | Matthiola W.T.Aiton | 
| Mattiastrum Brand | |
|  | Matucana Britton & Rose | 
|   | Mayaca Aubl. | 
|   | Maytenus (Speg.) Lourteig, O'Donell & Sleumer | 
|   | Meconopsis Vig. | 
|   | Medeola Gronov. ex L. | 
|   | Medicago L. | 
|   | Medinilla Gaudich. | 
| Megacorax Elizondo et al. | |
| Megahertzia A.S.George & B.Hyland | |
| Megaleranthis Ohwi | |
|   | Melaleuca Mant. | 
|   | Melampyrum L. | 
|   | Melanocalyx (Fed.) Morin | 
| Melanortocarya Selvi, Bigazzi, Hilger & Papini | |
|   | Melastoma L. | 
|   | Melittis L. | 
|   | Melocactus (L.) Link & Otto | 
|   | Melpomene A.R.Sm. & R.C.Moran | 
|   | Memecylon L. | 
| Mendoncia Vell. ex Vand. | |
|   | Menodora Humb. and Bonpl. | 
|   | Mentzelia Plum. ex L. | 
|  | Menyanthes L. | 
|   | Meriania Sw. | 
|   | Merremia Dennst. ex Endl. | 
|   | Mertensia Roth | 
| Merwilla Speta | |
|   | Mesembryanthemum L. | 
|   | Mesosphaerum P.Browne | 
| Mestoklema N.E.Br. ex Glen | |
| Metanemone W.T.Wang | |
|   | Metrosideros Banks ex Gaertn. | 
| Meyerophytum Schwantes | |
|   | Michauxia L'Hér. | 
|   | Miconia Ruiz & Pav. | 
|  | Micranthes Haw. | 
|   | Micranthocereus Backeb. | 
|   | Microchirita (C.B.Clarke) Yin Z.Wang | 
| Microconomorpha (Mez) Lundell | |
|   | Microcycas (Miq.) A.DC. | 
|   | Microgramma C.Presl | 
|   | Micromeria Benth. | 
| Micropleura Lag. | |
|   | Microsorum Link | 
|   | Microsteris Greene | 
|   | Microtropis E.Mey. | 
|   | Mikania Willd. | 
| Mikaniopsis Milne-Redh. | |
| Mila Britton & Rose | |
|   | Milla Cav. | 
|   | Millettia Wight & Arn. | 
|   | Milligania Hook.f. | 
|   | Mimetes Salisb. | 
|   | Mimosa L. | 
|   | Mimulus L. | 
|  | Miqueliopuntia F. Ritter | 
| Mirabella F. Ritter | |
|   | Misodendrum Banks ex DC. | 
|   | Mitchella L. | 
|   | Mitella L. | 
|   | Mitragyna Korth. | 
|   | Mitrasacme Labill. | 
| Mitrastemon Makino | |
|   | Mitreola L. | 
|   | Mitrephora Hook.f. & Thomson | 
| Mitrophyllum Schwantes | |
|   | Mohavea A.Gray | 
|   | Moltkia Lehm. | 
|   | Monanthes Haw. | 
|   | Monarda L. | 
|   | Moneses Salisb. ex Gray | 
|   | Monilaria (Schwantes) Schwantes | 
|   | Monnina Ruiz & Pav. | 
| Monochoria C. Presl | |
|   | Monocostus K.Schum. | 
|   | Monolluma Plowes | 
| Monoon Miq. | |
| Monoporus A.DC. | |
|   | Monotropa L. | 
|   | Monotropsis Schwein. ex Elliott | 
| Monsonia L. | |
|   | Monstera Adans. | 
|   | Montiopsis Kuntze | 
|   | Monttea Gay | 
|   | Mora Schomb. ex Benth. | 
|  | Moraea Mill. | 
|   | Morchella Dill. ex Pers. | 
|   | Moricandia DC. | 
|   | Morina L. | 
|   | Moschopsis Phil. | 
| Mossia N.E.Br | |
| Muehlbergella Feer | |
| Muehlenbeckia Meisn. | |
| Muilla S.Watson ex Benth. | |
| Muiria N.E.Br | |
| Mulguraea N.O'Leary & P.Peralta | |
|   | Mundulea Benth. | 
|   | Muraltia Neck. | 
|   | Murdannia Royle | 
|  | Murraya J.Koenig ex L. | 
|   | Musa L. | 
|   | Muscari Mill. | 
| Muscarimia Kostel. ex Losinsk. | |
|   | Musella (Franch.) C.Y.Wu ex H.W.Li | 
| Musgravea F.Muell. | |
|   | Musineon Raf. | 
| Mutellina Wolf | |
|   | Mutisia L.f. | 
|   | Myoschilos Ruiz & Pav. | 
|   | Myosotidium Hook. | 
|   | Myosotis L. | 
|   | Myricaria Desv. | 
|   | Myrmecodia Jack | 
| Myrsine L. | |
| Myrtgerocactus Moran | |
|   | Myrtillocactus Console | 
|   | Mystropetalon Harv. | 
| Mytilaria Lecomte |