Genista growing wild in the garrigue with its bright yellow flowers and rich honey scent in May is one of the great experiences of the Mediterranean. It also grows well here and is particularly useful for informal hedging and edging on dry slopes and next to dusty roads.
But the more cultivated forms of Cytisus (Broom) are also worth bearing in mind for the garden: the range of colours is very wide (reds, oranges and pinks as well as yellow) and the ability to flourish in poor soil, even pure sand, is not to be dismissed lightly. The plants can get leggy after a while and the RHS advises trimming the dead flowers and about 2/3 of the previous year's growth to keep them nice (how to tell what grew last year?). My only attempt at this resulted in the loss of the whole plant so be careful - perhaps better to just replace the plants every few years.