The Collaborative International Dictionary of English v.0.48:
Snakeroot \Snake"root`\, n. (Bot.)
Any one of several plants of different genera and species,
most of which are (or were formerly) reputed to be
efficacious as remedies for the bites of serpents; also, the
roots of any of these.
Note: The Virginia snakeroot is Aristolochia Serpentaria;
black snakeroot is Sanicula, esp. Sanicula
Marilandica, also Cimicifuga racemosa; Seneca
snakeroot is Polygala Senega; button snakeroot is
Liatris, also Eryngium; white snakeroot is
Eupatorium ageratoides. The name is also applied to
some others besides these.