Persicaria tinctoria

Persicaria tinctoria is a species of flowering plant in the buckwheat family. Common names include Chinese indigo, Japanese indigo and dyer's knotweed.^[2][3][4] It is native to Southern China and Vietnam, and has been introduced to other parts of China, as well as Germany, Japan, Korea, Tibet, North and South Caucasus, parts of the Russian Far-East, and Ukraine.^[5]

Persicaria tinctoria
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Order:	Caryophyllales
Family:	Polygonaceae
Genus:	Persicaria
Species:	P. tinctoria
Binomial name
Persicaria tinctoria (Aiton) Spach 1841
Synonyms[1]
Polygonum tinctorium Aiton 1789 Ampelygonum tinctorium (Aiton) Steud. Persicaria tinctoria (Aiton) H. Gross Pogalis tinctoria (Aiton) Raf.

The leaves are a source of indigo dye. It was already in use in the Western Zhou period (c. 1045 BC – 771 BC), and was the most important blue dye in East Asia until the arrival of Indigofera from the south.

See also

• Indigofera tinctoria