Fls 4-merous; sep lance-linear to ovate; cor salverform or funnelform to subrotate; stigmas 2; capsule partly to wholly inferior, with several to many seeds in each of the 2 locules, loculicidally dehiscent across the top; mostly herbs with small, opposite lvs and rather small to minute fls. (Houstonia, Oldenlandia) 300, cosmop., especially in warm regions. Spp. 1-4 apparently hybridize.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.