tarweed Meaning, Definition & Usage

  1. noun any of various resinous glandular plants of the genus Madia; of western North and South America
  2. noun any of various western American plants of the genus Grindelia having resinous leaves and stems formerly used medicinally; often poisonous to livestock
    rosinweed; gumweed; gum plant.

WordNet

Tar"weed` noun
Definitions
  1. (Bot.) A name given to several resinous-glandular composite plants of California, esp. to the species of Grindelia, Hemizonia, and Madia.

Webster 1913