There are about 15 species from the campanulaceae, or bellflower family in the British Isles. They have alternate, undivided leaves, and (usually) blue or purple flowers with a five-lobed calyx, a five-lobed, tubular or bell-shaped corolla, and five stamens. Most species produce relatively large flowers, in open panicles or racemes, but some are smaller, part of a dense, flowerhead-like cluster.