An annual herb with many, spreading or ascending stems. Leaves opposite, ovate,obtuse, and hairy, arising immediately below the bract and spreading beyond theinflorescence. Flowers bluish pink, purplish and in terminal spikes. (India) A perennial herbaceous plant reaching 20-30cm in height (Korea) Biennial or perennial herb 20 - 30cm high. Stems quadrangular, pubescent, reddish-violet leaves opposite, entire or slightly toothed. Inflorescence in terminal spike ofnumerous whorls; flowers of two kinds, the small female, the bigger bisexual, paleviolet. Fruit of 4 hard nutlets (Vietnam)