Description from Flora of China
Shrubs or trees, evergreen [or woody vines in E North America]. Leaves spirally arranged or pseudoverticillate [or in whorls of 3 in NE Asia], petiolate; leaf blade leathery, margin entire to strongly toothed. Inflorescences terminal or axillary, paniculate or racemose. Pedicels ± pubescent and with glandular hairs. Flowers 5-merous. Calyx valvate, abaxially glandular, adaxially pubescent. Corolla white, urceolate to tubular-urceolate, shortly 5-lobed. Stamens included; filaments swollen at base, straight or geniculate; anthers on back with a pair of spurs at anther-filament junction, dehiscing by introrse-terminal and elliptic pores. Ovary superior, with many ovules per locule. Stigma truncate. Capsule loculicidal, with 5 unthickened sutures. Seeds small.
Seven species: E Asia, Caribbean Region, E North America; three species (one endemic) in China.
(Authors: Fang Ruizheng (方瑞征 Fang Rhui-cheng); Peter F. Stevens)