The Collaborative International Dictionary of English v.0.48:

Colicroot \Col"ic*root`\, n.
   A bitter American herb of the Bloodwort family, with the
   leaves all radical, and the small yellow or white flowers in
   a long spike (Aletris farinosa and Aletris aurea). Called
   sometimes star grass, blackroot, blazing star, and
   unicorn root.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Aletris aurea
    n 1: colicroot with yellow-bracted racemose flowers; smaller
         than Aletris farinosa; southeastern United States [syn:
         yellow colicroot, Aletris aurea]