Bistorta amplexicaulis (synonym Persicaria amplexicaulis), the red bistort or mountain fleece, is a species of flowering plant in the buckwheat family, native to China, the Himalayas, and Pakistan. It is a damp-loving herbaceous perennial growing to 1.2 m (4 ft) tall and wide, with heart-shaped pointed leaves, downy beneath, and narrow spikes of rose-red or white flowers in summer. Numerous cultivars have been developed for garden use, including 'Firetail'.