​ PELLITORY, in botany, the common name for a small hairy perennial herb which grows on old walls, hedge banks and similar localities, and is known botanically as Parietaria officinalis (Lat. paries, a wall). It has a short woody rootstock from which spring erect or spreading stems 1 to 2 ft. long, bearing slender leafy branches, and axillary clusters of small green flowers. It belongs to the nettle order (Urticaceae), and is nearly allied to the nettle, Urtica, but its hairs are not stinging.