The Collaborative International Dictionary of English v.0.48:

Self-heal \Self`-heal"\, n. (Bot.)
   A blue-flowered labiate plant (Brunella vulgaris); the
   healall.
   [1913 Webster]

WordNet (r) 3.0 (2006):

self-heal
    n 1: decumbent blue-flowered European perennial thought to
         possess healing properties; naturalized throughout North
         America [syn: self-heal, heal all, Prunella vulgaris]