A compact, upright, bushy, borderline hardy, deciduous perennial with aromatic, lance-shaped, deeply veined, dark green leaves and, from midsummer into autumn, slender, whorled spikes of tubular, two-lipped, violet-blue flowers with reddish-purple calyces.
Height 60cm (2ft), Spread 50cm (1.5ft), 2-5 years to maturity.