[Wikipedia] Etymology, Distribution, Allergy, Native of Europe, Asia and Africa: 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.[2] In Australia it is also known as asthma weed, due to the high incidence of allergy.[3] It is unrelated to the herb pellitory (Anacyclus pyrethrum). It is easily confused with the very similar species Parietaria officinalis.[4] Etymology Parietaria (Latin): Wall-dweller (a name used by the Roman naturalist and philosopher Pliny). Judaica (Latin): Of Judaea, Jewish, from Palestine.[5] Distribution Parietaria judaica is a native of Europe, central and western Asia and northern Africa.[6] Allergy Causes allergic reactions in some people.[6][7] (link added by Mary Ann Machi)