''Fagopyrum cymosum'', also known as tall buckwheat, is a

domesticated Domestication is a sustained multi-generational relationship in which humans assume a significant degree of control over the reproduction and care of another group of organisms to secure a more predictable supply of resources from that group. A ...

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...

used in

traditional Chinese medicine Traditional Chinese medicine (TCM) is an alternative medical practice drawn from traditional medicine in China. It has been described as "fraught with pseudoscience", with the majority of its treatments having no logical mechanism of action ...

, for animal feed, and as an ornamental plant. It is native to much of China, and to Bhutan, Nepal, India, Burma, and Vietnam.

Chemistry

The flowers are known for their high content of

fagopyrin Fagopyrin is a term used for several closely related naturally occurring substances in the buckwheat plant. Their chemical structure contains a naphthodianthrone skeleton similar to that of hypericin Hypericin is a naphthodianthrone, an anthr ...

, a naphthodianthrone that provokes phototoxic effects known as fagopyrism.

References

cymosum Cereals Crops originating from Asia Flora of Asia Pseudocereals {{Polygonaceae-stub