Pellitory of the wall; a genus of the order of monoeica belonging to the polygamia class of plants. There are six species, of which one named the officinalis, is used in medicine. This has a creeping root. The stalk grows erect, is rough to the touch, and adhesive. The leaves are alternate, elliptical, lanceolate, veined, and a little rough. The flowers grow out of the axil of the leaves, in sessile, branched, verticillate clusters, of a greenish colour tinged with red. The anthers have a great degree of tenacity; for, if irritated with the point of a pin, they fly from the calyx with elastic force, and throw out their powder.—The plant has a cooling and diuretic quality. Three ounces of the juice taken internally, or a fomentation externally applied, have been found serviceable in the strangury.—The plant laid upon heaps of corn infested with weevils, is said to drive away those destructive insects.