in botany, a genus of the angiospermae order, belonging to the didynamia class of plants. There are three species, viz. the Glabra, the Hirtuta, and the Pendleton. They are natives of North America; and are herbaceous flowery perennials, with upright stalks two feet high, decorated with pear-shaped leaves, and beautiful spikes of monopetalous, ringent flowers, red, rose-coloured, blue, and purple. They flower from September to November, and are sometimes succeeded by ripe seeds in this country. They are very hardy plants, and may be propagated by seeds sown in any soil or situation; but the two first multiply so fast by their creeping roots, that the seeds are seldom regarded.