Shrubs or herbs; branches often quadrangular; leaves simple, opposite or whorled, often aromatic-spicy; stipules none; flowers solitary or in verticillasters, these in racemes, spikes, heads, or panicles; flower subtended by bract(s); calyx 5-lobed, bilabiate; corolla 4 5-lobed, bilabiate; stamens 4 or 2, inserted on the corolla; ovary superior, 4-lobed, 2-carpellate, cells 1-ovulate (carpel bicelled), style usually gynobasic; stigma bilobed; fruit usually of 2 or 4 dry nutlets, rarely drupaceous. About 160 genera and 3000 species, cosmopolitan, but chiefly of temperate or arid regions. No native species in Guam, but 11 exotic species in five genera are present.