is a perennial herb found in grasslands; stems grow straight upward,
without branching, to 40-80cm in height. Leaves are of opposite
phyllotaxis, in the shape of an oval to oblong, 6-14cm in length.
Flower buds appear in masses from leaf axils on upper parts and
bloom in the way of one- to plural-layered groups - the flowers are
dark brown-purple. Bloom time: June.