Bistorta affinis 'Superba' (knotweed 'Superba') is a matforming herbaceous perennial from the Polygonaceae family, suited to boggy conditions. It is a semi-evergreen plant that grows to a height of 0.1 to 0.5 metres and spreads between 0.5 and 1 metre, reaching full size over 5 to 10 years. This cultivar thrives in full sun or partial shade and is adaptable to all garden aspects and exposure levels. It prefers moist but well-drained or poorly-drained soils, including clay and loam, across a range of pH levels from acid to alkaline. It is notable for its interest during the winter season.

Knotweed 'Superba' (Bistorta affinis) is a semi-evergreen, mat-forming perennial ideal for boggy soils, providing winter interest in full sun or partial shade.

Bistorta affinis 'Superba'

Knotweed 'Superba' | Bistorta affinis 'Superba'

Bistorta affinis, the Himalayan bistort, fleece flower, or knotweed, is a species of flowering plant in the family Polygonaceae, native to the Himalayas.

Persicaria affinis 'Darjeeling Red' is a hardy perennial ideal for borders and groundcover, thriving in full sun to partial shade with attractive foliage.

https://en.wikipedia.org/wiki/Bistorta_affinis

Bistorta is a genus of flowering plants in the family Polygonaceae. As of February 2019 about 40 species are accepted.

Persicaria affinis 'Darjeeling Red'

Persicaria affinis 'Donald Lowndes' is a hardy perennial groundcover ideal for borders and rock gardens, thriving in full sun or partial shade.

Persicaria affinis 'Donald Lowndes'

Persicaria affinis 'Superba' is a mat-forming perennial in the Polygonaceae that forms dense clumps roughly 25 cm high and 60 cm across. It bears cylindrical spikes of pale pink to rose-red flowers from June to August. Leaves are produced mainly at ground level, creating a close carpet beneath the flowering stems.

Persicaria affinis 'Superba' is a mat-forming perennial that flowers from June to August.

Persicaria affinis 'Superba'

Himalayan Bistort | Persicaria affinis 'Superba'

Bistorta amplexicaulis, the red bistort or mountain fleece, is a species of flowering plant in the buckwheat family Polygonaceae, 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.

Persicaria amplexicaulis 'Alba' is a damp-loving herbaceous perennial ideal for borders and cottage gardens, thriving in full sun or partial shade with H5

https://en.wikipedia.org/wiki/Bistorta_amplexicaulis

Persicaria amplexicaulis 'Alba'

Persicaria amplexicaulis 'Blackfield' is a damp-loving herbaceous perennial, hardy to H5, ideal for borders and cottage gardens with summer flowers.

Persicaria amplexicaulis 'Blackfield'

Persicaria amplexicaulis 'Fat Domino' is a hardy herbaceous perennial growing to 1.2m, ideal for borders and cottage gardens in full sun or partial shade.

Persicaria amplexicaulis 'Fat Domino'

Red bistort (Persicaria amplexicaulis 'Inverleith') is a hardy herbaceous perennial ideal for borders and cottage gardens, thriving in full sun or partial

Persicaria amplexicaulis 'Inverleith'

Persicaria amplexicaulis 'JS Calient' is a hardy herbaceous perennial for borders and cottage gardens, thriving in damp soil with full sun or partial shade.

Persicaria amplexicaulis 'JS Calient'

Red bistort (Persicaria amplexicaulis 'Rosea') is a hardy herbaceous perennial for borders and cottage gardens, thriving in full sun or partial shade.

Persicaria amplexicaulis 'Rosea'

Red bistort (Persicaria amplexicaulis 'Taurus') is a hardy herbaceous perennial for borders and cottage gardens, thriving in full sun or partial shade.

Persicaria amplexicaulis 'Taurus'

Bistorta officinalis, known as bistort, common bistort, European bistort, or meadow bistort, is a species of flowering plant in the dock family Polygonaceae native to Europe and northern and western Asia. Other common names include snakeroot, snake-root, snakeweed, and Easter-ledges.

Persicaria bistorta 'Superba' is a hardy perennial ideal for borders and damp areas, thriving in full sun to partial shade with attractive summer blooms.