PARIETARIA, PELLITORY of the WALL; a genus of the order of monocotyledons 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 ala of the leaves, in sessile, branched, verticillate clusters, of a greenish colour tinged with red. The antheræ have a great degree of sensibility; for, if irritated with the point of a pin, they fly from the calix 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 stranguary.—The plant laid upon heaps of corn infested with weevils, is said to drive away those destructive insects.