Cal at anthesis small, 5-lobed, the tube enlarging promptly thereafter, becoming membranous and strongly veiny, loosely but completely enclosing the fr, often 5-angled and often retuse at base, its lobes connivent in fr and scarcely enlarged; cor broadly funnelform or campanulate, shallowly lobed to entire, usually yellow or yellowish, often with 5 large dark spots within, seldom white; stamens inserted near the base of the cor, opening longitudinally; berry pulpy, many-seeded; mostly herbs, commonly widely branching, with alternate or seemingly opposite lvs; fls solitary or less often 2+ at the nodes on drooping pedicels. 90, ±cosmop., but esp. New World.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.