(n) any of various western American plants of the genus Grindelia having resinous leaves and stems formerly used medicinally; often poisonous to livestock, Syn. gum plant, tarweed, rosinweed
The Collaborative International Dictionary of English (GCIDE) v.0.53 Collaborative International Dictionary (GCIDE)
n. (Bot.) (a) The compass plant. See under Compass. (b) A name given in California to various composite plants which secrete resins or have a resinous smell. [ 1913 Webster ]