The Collaborative International Dictionary of English v.0.48:

Carline thistle \Car"line this`tle\ [F. carline, It., Sp., &
   Pg., carlina. Said to be so called from the Emperor
   Charlemagne, whose army is reputed to have used it as a
   remedy for pestilence.] (Bot.)
   A prickly plant of the genus Carlina (Carlina vulgaris),
   found in Europe and Asia.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Carlina vulgaris
    n 1: Eurasian thistle growing in sand dunes and dry chalky soils
         [syn: common carline thistle, Carlina vulgaris]