- ‘Mabel Blackwell’
- ‘Maculata Superba’
- ‘Madame de Cannart d’Hamale’
- ‘Madame de Strekaloff’
- ‘Madame Haas’
- ‘Madame Lebois’
- ‘Madame Martin Cachet’
- ‘Madame Victor de Bisschop’
- ‘Madge Miller’
- ‘Maestosa’
- ‘Magic Moments’
- ‘Magnoliiflora’
- ‘Maiden’s Blush’
- ‘Maiden’s Blush’
- ‘Man Size’
- ‘Marchesa d’Ambra’
- ‘Margaret Crozier’
- ‘Margaret Davis’
- ‘Margaret Rose’
- ‘Margaret Short’
- ‘Margaret Waterhouse’
- ‘Margarete Hertrich’
- ‘Margherita Coleoni’
- ‘Marguerite Gouillon Rose’
- ‘Marian Mitchell’
- ‘Mariann’
- ‘Marianna Gaeta’
- ‘Marie Bracey’
- ‘Marjorie Magnificent’
- ‘Marjorie Waldegrave’
- ‘Mark Alan’
- ‘Maroon and Gold’
- ‘Mars’
- ‘Martha Brice’
- ‘Mary Alice Cox’
- ‘Mary Christian’
- ‘Mary Costa’
- ‘Mary J. Wheeler’
- ‘Mary Larcom’
- ‘Mary Phoebe Taylor’
- ‘Mary Williams’
- ‘Masayoshi’
- ‘Masquerade’
- ‘Masterpiece’
- ‘Mathotiana Alba’
- ‘Mathotiana Rosea’
- ‘Mathotiana Rubra’
- ‘Mathotiana Supreme’
- ‘Matterhorn’
- ‘Mattie Cole’
- ‘Maud Messel’
- ‘Mercury’
- ‘Mercury Variegated’
- ‘Mermaid’
- ‘Merry Christmas’
- ‘Michael’
- ‘Midnight’
- ‘Midnight Magic’
- ‘Midnight Serenade’
- ‘Mignonne’
- ‘Mikenjaku’
- ‘Mildred Veitch’
- ‘Milo Rowell’
- ‘Mimosa Jury’
- ‘Minato-no-akebono’
- ‘Mine-no-yuki’
- ‘Ming Temple’
- ‘Minnie Maddern Fiske’
- ‘Mirage’
- ‘Miss Charleston’
- ‘Mississippi Beauty’
- ‘Miss Lyla’
- ‘Miss Tulare’
- ‘Miss Universe’
- ‘Moira Reid’
- ‘Momijigari’
- ‘Mona Lisa’
- ‘Monarch’
- ‘Monica Dance’
- ‘Monsieur Faucillon’
- ‘Monte Carlo’
- ‘Monticello’
- ‘Moonlight’
- ‘Moonlight Bay’
- ‘Moonlight Sonata’
- ‘Moshe Dayan’
- ‘Moshio’
- ‘Mrs Anne Marie Hovey’
- ‘Mrs Bell’
- ‘Mrs Derlacquer’s Beauty’
- ‘Mrs D.W. Davis’
- ‘Mrs D.W. Davis Descanso’
- ‘Mrs Lyman Clarke’
- ‘Mrs Swan’
- ‘Mrs T Brockhouse’
- ‘Mrs Tingley’
- ‘Mrs William Thompson’
- ‘Muskoka’
- ‘Mystique’