Description: Woody, climbing or sometimes creeping perennial vines, occasionally shrubby.
Leaves opposite or whorled; margins entire; usually with interpetiolar stipule present.
Inflorescence of solitary axillary flowers, axillary or terminal pairs or clusters to large compound cymes. Flowers bisexual, 5-merous. Calyx free; glabrous or ciliate. Corolla funnel-shaped; lobes imbricate in bud. Stamens inserted at base of corolla tube; anthers sagittate; exserted; glabrous. Ovary 2-locular, ovules many per locule; stigmas with 4 papillose lobes.
Capsule septicidal or loculicidal; 2-valved. Seeds flat, outline irregular; wing thin (often at one end of seed) or absent.
Distribution and occurrence: World: 3 species, SE North America, C America & Asia. Australia: 1 species (doubtfully naturalized).
Text by B. J. Conn