Source : Webster's Revised Unabridged Dictionary (1913)

Myrtaceous \Myr*ta"ceous\, a. [L. myrtaceus.] (Bot.)
   Of, pertaining to, or resembling, a large and important
   natural order of trees and shrubs ({Myrtace[ae]}), of which
   the myrtle is the type. It includes the genera {Eucalyptus},
   {Pimenta}, {Lechythis}, and about seventy more.