Geranium malviflorum

A less common but much better relative of the familiar G.tuberosum - this has much larger flowers of a rich violet mauve. Like G.tuberosum it comes up in winter, flowers in mid spring and disappears again in summer - ideal ground-cover for summer-growing herbaceous plants and deciduous shrubs.
Drought tolerant but good even on retentive heavy soils.  
1L square pots ~ £5