The Collaborative International Dictionary of English v.0.48:

fiddleneck \fiddleneck\ n.
   hairy annual plant (Phacelia tanacetifolia) of California
   to Mexico with crowded cymes of small blue to lilac or mauve
   flowers.

   Syn: Phacelia tanacetifolia.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

fiddleneck
    n 1: hairy annual of California to Mexico with crowded cymes of
         small blue to lilac or mauve flowers [syn: fiddleneck,
         Phacelia tanacetifolia]