This hardy perennial which began to flower in spring is still going strong though it has become so tall (35cm) that it is due for a severe cut back .The great thing about this plant is that you can cut it off at ground level and it will grow straight back up and start to flower again. This variety has very loud coloured foliage and flowers. The clump of grassy leaves are bright yellow or lime green and the flowers are vivid purple or dark blue. The flowers are sun sensitive however so you only see them in the early morning or on dull overcast days. There are some more subdued cultivars of this plant including the soft blue grey "Osprey" as well as pure white, pale mauve ,pink and a double flowering blue.It is a very hardy plant across a range of climates and will grow in full sun or light shade.2017 update: I still grow this though I am currently out of stock.