LEWISIA

These brightly coloured, early spring-flowering alpine plants are perfect for rock and crevice gardens or tumbling down a stone wall

- RICHARD WILFORD

Lewisias, also known as cliff maids, are plants that grow in cracks and crevices and will thrive in gaps in a stone wall, displaying colourful flowers in spring and early summer. Low-growing perennials, they form a rosette of fleshy leaves. The flowers are held singly or in a branched inflorescence and can be incredibly vibrant, especially in the strains and hybrids selected to highlight the bright colours found in wild species.

Lewisia is a genus of around 16 species from the western side of North America, particularly the Rocky Mountains, Cascade Range and Sierra Nevada. They are usually found on rocky slopes, screes or in crevices on vertical cliffs, where the summers are dry. The genus is named after Captain Meriwether Lewis, who along with William Clark, led an expedition across America from St Louis, Missouri, to the Pacific Ocean in the years 1804 to 1806. Among the specimens collected was the plant later named Lewisia rediviva in 1813 by Frederick Pursh in his Flora Americae Septentrionalis (Flora of North America).

Lewisia rediviva, the state flower of Montana, is one of the most beautiful in the genus. This is one of the deciduous species, going dormant in summer, but in spring it produces wide, almost stemless, solitary, soft-pink flowers, up to 7.5cm across with up to 19 petals. Bitterroot is another common name for lewisias and it comes from this plant, referring to the taste of the fleshy rootstock, which is eaten by indigenous Americans. This remarkable plant has been known to regrow from pressed herbarium specimens but although very tough, it will not survive a wet summer outside. The evergreen species, and the hybrids derived from them, are much more amenable to outdoor cultivation, as long as the soil drains freely.