The Collaborative International Dictionary of English v.0.48:

Botanic \Bo*tan"ic\, Botanical \Bo*tan"ic*al\, a. [Cf. F.
   botanique. See Botany.]
   Of or pertaining to botany; relating to the study of plants;
   as, a botanical system, arrangement, textbook, expedition. --
   Bo*tan"ic*al*ly, adv.
   [1913 Webster]

   Botanic garden, a garden devoted to the culture of plants
      collected for the purpose of illustrating the science of
      botany.

   Botanic physician, a physician whose medicines consist
      chiefly of herbs and roots.
      [1913 Webster]