Erinus alpinus, the fairy foxglove, alpine balsam, starflower, or liver balsam, is a species of flowering plant in the family Plantaginaceae (previously in the family Scrophulariaceae), native to Central and Southern Europe and also to Morocco and Algeria.
|Erinus alpinus flowering in a crack in mortar|
It is popularly grown in rockeries or alpine gardens; and occasionally becomes naturalised outside its native range, especially on old stone walls, shown from a well-known location for this species on the old Carrbridge Packhorse Bridge in the Highlands of Scotland 
In folk belief of Northumberland edit
Fairy foxglove is a small, purple flower which grows intermittently on stone walls in north-east England. Local tradition says that it only grows where Roman soldiers have trod. And certainly it is to be found in the village of Wall (which is, of course, located near Hadrian's Wall in Northumberland).
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