The Collaborative International Dictionary of English v.0.48:

Wartwort \Wart"wort`\, n. (Bot.)
   A name given to several plants because they were thought to
   be a cure for warts, as a kind of spurge (Euphorbia
   Helioscopia), and the nipplewort (Lampsana communis).
   [1913 Webster]

WordNet (r) 3.0 (2006):

wartwort
    n 1: not unattractive European weed whose flowers turn toward
         the sun [syn: sun spurge, wartweed, wartwort,
         devil's milk, Euphorbia helioscopia]