Berberis calliantha

The spiny edged foliage is glossy green above and white underneath and the flowers are lemon yellow – nothing unusual about any of that - except that the leaves and flowers are bigger than any similar species – the leaves up to 2ins long and the flowers an inch across, and all this on a low compact shrub not more than 3ft tall. At the same time this is as hardy and adaptable as any of the more familiar types. 

Many people dismiss Berberis as just a lot of dull scruffy spikey shrubs, too often planted around carparks (and full of litter) but there are quite a few good, interesting species for the more discerning gardener – and calliantha is one.  
£16