Cal usually 10-nerved, 2-lipped, the lips longer than the broad tube, the lower cleft to its base into narrowly triangular lobes, the upper cleft half length into broadly triangular lobes, the middle lobe the shortest; fruiting cal enlarged, hairy within; cor-tube about equaling the cal, the lips short, shallowly lobed; fertile stamens 2, straight; nutlets globose, areolate; annuals with small fls borne 2 at each node in the axils of small bracts, forming a slender, interrupted terminal spike. (Orthodon) 15, e. Asia.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.