Lavatera oblongifolia is a member of the Malva genus in the Malvaceae family, sharing the mallow group's characteristic five-petalled flowers and palmately lobed leaves. Plants in this genus range from herbaceous to woody and may be annual, biennial or perennial. It is used in cultivation for summer flowering and is regarded among mallows as a short-lived perennial in garden practice. Flowering runs from June to September.

Lavatera oblongifolia is a mallow-family plant that flowers in the UK from June to September.

Malva is a genus of herbaceous or woody, annual, biennial, and perennial plants in the family Malvaceae. It is one of several closely related genera in the family to bear the common English name mallow.

Lavatera oblongifolia

Malva alcea, the greater musk mallow, is a herbaceous perennial that reaches about 1.2 m and carries upright flowering stems with pink blooms from June to September. It suits full sun and prefers soils that are moist but well drained, from sandy through loam to clay. Fully hardy in the UK (H7), it is long-lived once established. Its stature and summer flowering make it a clear structural plant in mixed plantings.

Greater musk mallow (Malva alcea) is a fully hardy perennial with pink flowers from June to September and prefers full sun and moist, well-drained soil.

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

Malva alcea

Greater musk mallow | Malva alcea

Malva alcea 'Fastigiata' is a perennial mallow that reaches about 1.2 m, carrying upright stems topped with five-petalled pink flowers. It prefers full sun and tolerates sandy, loamy or clay soils provided they are moist but well-drained. Flowering runs from June to September. It is fully hardy in UK conditions (H7).

Malva alcea 'Fastigiata' is a full-sun perennial mallow to about 1.2 m with pink flowers from June to September.

Malva alcea 'Fastigiata'

Greater Musk-mallow | Malva alcea 'Fastigiata'

A perennial herb reaching about 0.8 m, Malva moschata alba produces white summer flowers and foliage with a musky scent. It flowers from June to September. Plant it in full sun on moist but well-drained soil, with tolerance of sandy, loamy or clay types. It is fully hardy (H7) in the UK.

White musk mallow (Malva moschata alba) is a 0.8 m perennial with fragrant foliage and white flowers, flowering June to September in full sun.