Source : Webster's Revised Unabridged Dictionary (1913)

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.

Source : WordNet®

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