[2] Reynoutria sachalinensis is a herbaceous perennial plant growing to 2–4 m (79–157 in) tall, with strong, extensively spreading rhizomes forming large clonal colonies.

The species is closely related to the Japanese knotweed, Reynoutria japonica, and can be distinguished from it by its larger size, and in its leaves having a heart-shaped (not straight) base and a crenate margin.

It came prominently into notice about 1893, when a drought in western Europe caused a decided shortage in forage for cattle.

[8][9] Rhizome of R. sachalinensis is the source of lactoperoxidase peroxidation cycle substrates, which can act as activators and inhibitors of the antimicrobial properties of that system.

[10] The species has been cultivated as an energy crop for biomass production, particularly in Germany in its commercial variety 'Igniscum', and it has shown a high productivity even in Northern latitudes, reaching a dry matter yield from 5.4 to 27.8 oven dry metric tons per hectare (2.4 to 12.4 short ton/acre), annually.