Parietaria judaica, with common names spreading pellitory or pellitory of the wall, is a species of herbaceous perennial plant in the family Urticaceae. The plant's pollen is highly allergenic. In Australia it is also known as asthma weed, due to the high incidence of allergy.
Pellitory is mildly toxic to humans, causing skin irritation when plant hairs cling to clothing, and allergic reactions through the pollen which is produced throughout the year but copiously in spring. Reactions include asthma, conjunctivitis, hay fever and severe skin irritation.
