Fls 5-merous; cal deeply lobed; cor campanulate, lobed to about the middle; stamens 5, included; anthers subglobose, opening longitudinally; pistil as long as the stamens; stigma capitate; ovary 2-3-locular; capsule ovoid, subtended by the persistent cal, septicidal, each of the 2-3 valves eventually 2-cleft. Monospecific.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.