parietaria . ( Of the lat. )( parietaria ). 1. f. herbaceous annual, the family of the Urticáceas, with reddish, stems erect, four to six decimetres, simple or with very short branches, the leaves are alternate, entire, petiolate, rough and lanceolate, flowers in axillary groups, small and greenish, and dry fruit, enveloped by the perigone. It grows ordinarily next to the walls and it has been used in poultices.