rattlesnake weed

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of various plants thought to be effective against the venom of rattlesnakes, such as the North American hawkweed Hieracium venosum, or thought to resemble rattlesnakes, such as the betony Stachys floridana, having roots resembling rattles.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a hawkweed with a rosette of purple-veined basal leaves; Canada to northern Georgia and Kentucky