Also known as C. mauritanicus, this tender rock bindweed is a native of north Africa and a popular trailing subject (strictly, prostrate climbing) for warm sunny positions. It has become a familiar ingredient of hanging baskets and containers, but was grown in the past as a summer subject for rock gardens, where the stems could bake on the stones and root wherever they touched the soil. By late summer the bushy plants are smothered in clear, soft blue trumpets. The Royal Horticultural Society has given it its Award of Garden Merit (AGM).
Bush Morning Glory is a glowing presence in the garden. The soft, silvery foliage forms a perfect rounded mound that brings a strong architectural form to the landscape. The color looks amazing contrasted with bright flowers or dark-leaved plants. In late spring the plant is literally covered with white trumpet-shaped flowers that look similar to Morning Glory flowers. Incredibly carefree; this plant thrives in poor soil, heat, and dry conditions too.
Sources: http://www.bbc.co.uk/gardening/plants/plant_finder/plant_pages/212.shtml
https://www.mygardenlife.com/plant-library/2614/convolvulus/cneorum