The Collaborative International Dictionary of English v.0.48:

phlox \phlox\ (fl[o^]ks), n. [L., a kind of flower, fr. Gr.
   flo`x flame, fr. fle`gein to burn.] (Bot.)
   A genus of American herbs, having showy red, white, or purple
   flowers.
   [1913 Webster]

   Phlox worm (Zool.), the larva of an American moth
      (Heliothis phloxiphaga). It is destructive to phloxes.


   Phlox subulata, the moss pink. See under Moss.
      [1913 Webster]

WordNet (r) 3.0 (2006):

phlox
    n 1: any polemoniaceous plant of the genus Phlox; chiefly North
         American; cultivated for their clusters of flowers