Originally (more fully "spotted persicaria"): a common Eurasian weed, Persicaria maculosa (formerly Polygonum persicaria), of the family Polygonaceae, which has spikes of small pink flowers and lanceolate leaves often bearing a dark blotch (also called redshank). In later use, usually with distinguishing word: any of the plants constituting the genus Persicaria (commonly treated as a section of the genus Polygonum); specifically the garden plant P. orientalis, a tall annual with dense spikes of rose-pink flowers, native to South-East Asia. Also (in form Persicaria): the genus (or section of the genus Polygonum) containing these plants.