Source : Webster's Revised Unabridged Dictionary (1913)

Lion's tail \Li"on's tail`\ (t[=a]l`). (Bot.)
   A genus of labiate plants ({Leonurus}); -- so called from a
   fancied resemblance of its flower spikes to the tuft of a
   lion's tail. {L. Cardiaca} is the common {motherwort}.