This is an extremely frost hardy, herbaceous perennial that forms a clump of narrow dark green foliage while producing lovely blue/purple daisy-like flowers with yellow centres from late spring through summer.
Being an alpine plant this will do best in cooler climates though it can withstand short periods of heat (or even fire).
Very good on banks, slopes, rockeries and borders, they are suited well to informal cottage style gardens as well as city courtyards, pots and planters.