Another glorious plant from the Himalayas (as high as 15,000ft) with rosettes of narrow, bristly, sword-shaped leaves, and bearing in summer, either from the upper leaf axils or directly from the base, beautiful rich blue flowers as much as 5½ins across and containing anything from four to nine petals. 3ft (90cm)

This genus contains some of the most exquisitely beautiful of all flowering plants. Not the easiest of plants to grow, they do best in moderately rich, woodland soil; moist yet with perfect drainage. However, do try them - we guarantee that when you succeed in flowering them, there will be celebrations and the neighbours will be invited in to see for themselves.