The Collaborative International Dictionary of English v.0.48:

fire-on-the-mountain \fire-on-the-mountain\ n.
   1. poinsettia (Euphoria cyathophora) of the U. S. and
      eastern Mexico; often confused with Euphoria
      heterophylla.

   Syn: painted leaf, Mexican fire plant, Euphoria
        cyathophora.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

fire-on-the-mountain
    n 1: poinsettia of United States and eastern Mexico; often
         confused with Euphorbia heterophylla [syn: fire-on-the-
         mountain, painted leaf, Mexican fire plant, Euphorbia
         cyathophora]