Liatris aspera is a perennial wildflower in the aster family that bears erect, unbranched stems topped with dense, purple, button-like flower heads. Plants typically reach 0.3–1.8 m tall and carry numerous narrowly lanceolate leaves along the stem. Flower heads open from the top downward and are produced July to September. It is native to central and eastern North America and occurs in prairies, glades and dry savannas.

Rough Blazing Star (Liatris aspera) flowers July to September with purple, button-like heads that attract butterflies and birds.

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

Liatris aspera

Rough Blazing Star (Liatris aspera) | Prairie Perennial

Liatris aspera is a perennial wildflower in the Asteraceae family that is found in central to eastern North America in habitats that range from mesic to dry prairie and dry savanna.

Liatris, commonly known as gayfeather and blazing star is a genus of flowering plants in the tribe Eupatorieae within the family Asteraceae native to North America. Some species are used as ornamental plants, sometimes in flower bouquets.

Liatris aspera 'Alba'

Liatris pycnostachya, the prairie blazing star, cattail gayfeather, Kansas gayfeather, or cattail blazing star, is a perennial plant in the Asteraceae family that is native to the tallgrass prairies of the central United States.

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

Liatris pycnostachya

Liatris scariosa 'White Spire' is a herbaceous perennial cultivar within the Liatris genus, known for its tufted habit and slender, grass-like leaves. This deciduous plant produces upright flower spikes that resemble bottlebrushes, with blooms emerging from the top and progressing downward. It thrives in full sun on south-facing aspects and adapts well to a variety of soil types including chalk, clay, loam, and sand, preferring moist but well-drained conditions. Hardy to UK zone H6, 'White Spire' is suitable for cottage and informal gardens, wildlife gardens, and prairie planting, offering seasonal interest from spring through autumn.

Liatris scariosa 'White Spire' is a hardy herbaceous perennial with upright bottlebrush flower spikes, ideal for full sun in cottage and wildlife gardens.

Liatris scariosa 'White Spire'

Liatris spicata, the dense blazing star, prairie feather, gayfeather or button snakewort, is a herbaceous perennial flowering plant in the family Asteraceae. It is native to eastern North America where it grows in moist prairies and meadows. The plants have tall spikes of purple flowers resembling bottle brushes or feathers that grow 1–5 ft (0.30–1.52 m) tall. The species grows in hardiness zones 3 - 8, stretching from the Midwest to the East Coast, eastern and western Canada. It grows to around 0.5-1 metres tall and 0.1-0.5 metres wide, carrying deciduous foliage. Grow it in full sun and most soil types. It tolerates soil of any pH, moist but well-drained conditions and south-facing aspects.

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

Liatris spicata

Liatris spicata, the dense blazing star, prairie feather, gayfeather or button snakewort, is a herbaceous perennial flowering plant in the family Asteraceae. It is native to eastern North America where it grows in moist prairies and meadows.

Liatris spicata 'Alba'

Liatris spicata 'Kobold' ('Gnome') is a compact perennial that bears upright spikes of deep purple flowers. It grows to about 0.6 m tall with a spread near 0.5 m and flowers from July to September. Plant in full sun on sandy or loamy soils that remain moist but are well drained. It is suited to borders, pollinator plantings and cutting for arrangements.

Dense Blazing Star (Liatris spicata 'Kobold' ('Gnome')) flowers July–September and suits sunny, moist sandy or loamy soils in the UK.