A rarely offered rock plant which is near enough herbaceous and emerges in early spring with small shoots which expand to produce the dense mats of green foliage. This is quite small but covers the ground very well. Each leaf is approximately 3 cms long or so and serrated. Flowers are very attractive and a deep violet-blue colour, bell-shaped and produced in rapid succession. Flowering period is mainly in mid to late summer and is good for extending the colour in a border or rock garden later in the season.