A compact, clump-forming, half-hardy, deciduous to semi-evergreen perennial with broad, strap-shaped, mid-green leaves, and, in summer, sturdy, erect stems bearing rounded umbels of star-shaped, pale blue to blue flowers with a dark violet-blue stripe down the centre of each petal.
Height 60cm (2ft), Spread 30cm (1ft), 2-5 years to maturity.