The Collaborative International Dictionary of English v.0.48:

martagon \mar"ta*gon\, n. [Cf. F. & Sp. martagon, It.
   martagone.] (Bot.)
   A lily (Lilium Martagon) with purplish red flowers, found
   in Europe and Asia.
   [1913 Webster]

WordNet (r) 3.0 (2006):

martagon
    n 1: lily with small dull purple flowers of northwestern Europe
         and northwestern Asia [syn: Turk's-cap, martagon,
         Lilium martagon]