The Collaborative International Dictionary of English v.0.48:

Redroot \Red"root`\ (r?d"r?t`), n. (Bot.)
   A name of several plants having red roots, as the New Jersey
   tea (see under Tea), the gromwell, the bloodroot, and the
   Lachnanthes tinctoria, an endogenous plant found in sandy
   swamps from Rhode Island to Florida.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Bloodroot \Blood"root`\, n. (Bot.)
   A plant (Sanguinaria Canadensis), with a red root and red
   sap, and bearing a pretty, white flower in early spring; --
   called also puccoon, redroot, bloodwort, tetterwort,
   turmeric, and Indian paint. It has acrid emetic
   properties, and the rootstock is used as a stimulant
   expectorant. See Sanguinaria.
   [1913 Webster]

   Note: In England the name is given to the tormentil, once
         used as a remedy for dysentery.
         [1913 Webster]

WordNet (r) 3.0 (2006):

redroot
    n 1: perennial woodland native of North America having a red
         root and red sap and bearing a solitary lobed leaf and
         white flower in early spring and having acrid emetic
         properties; rootstock used as a stimulant and expectorant
         [syn: bloodroot, puccoon, redroot, tetterwort,
         Sanguinaria canadensis]