The Collaborative International Dictionary of English v.0.48:

checkerbloom \checkerbloom\ n.
   a perennial purple-flowered wild mallow of West North America
   (Sidalcea malviflora) that is also cultivated.

   Syn: wild hollyhock, Sidalcea malviflora.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Sidalcea malviflora
    n 1: perennial purple-flowered wild mallow of western North
         America that is also cultivated [syn: checkerbloom, wild
         hollyhock, Sidalcea malviflora]