The Collaborative International Dictionary of English v.0.48:

cheeseflower \cheeseflower\ n.
   an erect or decumbent Old World perennial (Malva
   sylvestris) with axillary clusters of rosy-purple flowers;
   introduced into the U. S.

   Syn: tall mallow, high mallow, cheese, Malva sylvestris.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

cheeseflower
    n 1: erect or decumbent Old World perennial with axillary
         clusters of rosy-purple flowers; introduced in United
         States [syn: tall mallow, high mallow, cheese,
         cheeseflower, Malva sylvestris]