About 400 species of annuals and perennials of cosmopolitan distribution but mainly in the northern hemisphere (145 in Europe). They have square slender stems and simple leaves (mixed with similar stipules) in whorls. The small tubular to bell-shaped flowers, have either four narrow petal lobes in cross-formation, and are carried, in terminal panicles or singly from the leaf axils in summer.
Very few members of this genus are cultivated, probably because they lack a floral impact. However, many species are of local occurrence and seldom seen, and it may be that some of them have horticultural potential. The species from Turkey described below would seem to have promise. Well drained soil and a sunny site will be needed. Propagation by seed or division in early spring, basal cuttings in late spring and also seed when ripe. (all perennial)