What is "parietaria officinalis"

Pellitory \Pel"li*to*ry\, n. [OE. paritorie, OF. paritoire, F. pari['e]taire; (cf. It. & Sp. parietaria), L. parietaria the parietary, or pellitory, the wall plant, fr. parietarus belonging to the walls, fr. paries, parietis a wall. Cf. Parietary.] (Bot.) The common name of the several species of the genus Parietaria, low, harmless weeds of the Nettle family; -- also called wall pellitory, and lichwort.

Note: Parietaria officinalis is common on old walls in Europe; Parietaria pennsylvanica is found in the United States; and six or seven more species are found near the Mediterranean, or in the Orient.

Parietaria officinalis, the eastern pellitory-of-the-wall, also known as upright pellitory and lichwort, is a plant of the nettle family. Its leaves, however, are non-stinging. The plant grows on rubbish and on walls, hence the name.

The pollen is a cause of allergy.