Ambrosia

(am-bro' '-zhe-ah). A genus of coarse composite-flowered herbs. A. artemisicefolia, common hogweed of North America; is stimulant, tonic, antiperiodic, and astringent. A. trifid a, of the United States, has similar properties. The pollen of these plants is by some regarded as a cause of hayfever. Unof.