Cultivars
'Little Luna'
This perennial grows from 200 mm (8 in) to 300 mm (12 in) tall with spreading silver green pubescent foliage forming a mounded habit.  It produces single bright yellow tube-shaped flowers from spring to summer and grows in well-drained moderately fertile sandy to clay soils. 

It prefers an open sunny position tolerating heat and drought but is frost tender. This perennial may be used as an annual and is planted in rockeries or mixed with other perennials in garden borders and planted in patio pots or planter-boxes. It grows in USDA zones 9-11.

'Tenacity'
This plant has a low prostrate habit up to 1.5m (5ft) wide and produces yellow flowers throughout the year in warm climates and tolerating light frosts. It grows in most well drained slightly acidic soils in a sunny position.