Variation
var. minor
This variation grows to 150 mm (6 in) tall by 200 mm (8 in) wide and has smaller leaves and lavender blue or white flowers.

Cultivars
There are many cultivars and it is advisable to contact your local nursery for available varieties.

'Alba'
This group of perennials grows to 100 mm (4 in) tall by 500 mm (20 in) wide with bright green foliage forming a spreading habit. From spring to summer they produce pure white flowers that may be fragrant and appear above the foliage. They tolerate most well-drained organic rich moist soils and a pH adaptable, growing in an open sunny to partially shaded position in USDA zones 8-10.

'Bowles Black'
This perennial grows to 200 mm (8 in) by 300 mm (12 in) wide with dark green scalloped ovate leaves forming a compact clump. It has velvet textured black flowers with deep purple accents and golden eyes, and appears above the foliage throughout summer. It is planted in small cottage gardens long from borders as a bedding plant or grown in hanging baskets and patio pots. It grows in USDA zones 7-9.

'King Henry'
This perennial grows to 200 mm (8 in) by 300 mm (12 in) wide with dark green scalloped ovate leaves and forms a compact clump. It has deep purple flowers with lavender blue markings and golden eyes, and appears above the foliage throughout summer. It is planted in small cottage gardens long from borders as a bedding plant or grown in hanging baskets and patio pots. It grows in USDA zones 7-9.