The Collaborative International Dictionary of English v.0.48:

Hermodactyl \Her`mo*dac"tyl\, n. [NL. hermodactylus, lit.,
   Hermes' finger; fr. Gr. ? Hermes + ? finger.] (med.)
   A heart-shaped bulbous root, about the size of a finger,
   brought from Turkey, formerly used as a cathartic.
   [1913 Webster]