The Collaborative International Dictionary of English v.0.48:

Erythronium \Er`y*thro"ni*um\, n. [NL., from Gr. ? a kind of
   plant, fr. 'eryqro`s red.] (Chem.)
   A name originally given (from its red acid) to the metal
   vanadium. [R.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

Erythronium
    n 1: perennial bulbous herbs most of northern United States:
         dogtooth violet; adder's tongue; trout lily; fawn lily
         [syn: Erythronium, genus Erythronium]