Original: Other studies go as far as 55 species  including the domesticated Orchard Apple, or Table apple as it was formerly called (M. domestica, derived from M. sieversii, syn.
Simplified: Other studies go as far as to say it includes 55 species  including the domesticated Orchard Apple, or Table apple as it used to be called (M. domestica, derived from M. sieversii, syn.