senecio doronicum

from The Collaborative International Dictionary of English v.0.48

leopard's bane \leop"ard's bane`\ (l[e^]p"[~e]rdz b[=a]n`) n.
   (Bot.)
   A name of several harmless plants, as {Arnica montana}
   ({Arnica acaulis} syn. {Doronicum acaule}), {Senecio
   Doronicum}, and {Paris quadrifolia}.

   Syn: leopardbane, leopard's-bane.
        [1913 Webster +PJC]