Leaves opposite; calycine colleters present or absent; corolla salveriform; corona absent; corolla-lobe aestivation sinistrorse or dextrorse; style head scarcely differentiated, without basal collar, body uniformly receptive; ovary congenitally syncarpous; disc mostly absent or adnate to ovary.
Calycine colleters few, alternisepalous, or more numerous.
Calycine colleters usually few, alternisepalous, sometimes several and evenly spread across base of sepal.
Calycine colleters few and alternisepalous or numerous and spread across base of sepal inside (rarely absent); corolla salveriform, campanulate, or urceolate; corolla-lobe aestivation dextrorse (sinistrorse in Parameria), rarely valvate; corona, if present, mostly as small pouches in petal sinuses, sometimes lower down on corolla tube behind stamens (Apocynum with alternistaminal appendages near base of corolla tube).
Calycine colleters mostly in alternisepalous groups or in continuous ring, more rarely solitary and episepalous; corolla usually divided into narrow lower tube and expanded upper throat, mostly infundibuliform or tubular campanulate, more rarely tubular or salveriform; corolla-lobe aestivation dextrorse; distinct corona usually absent; stamens mostly inserted at base of throat; lignified guide rails long, well developed; style head with neither basal collar nor upper wreath, with 5 arms, which usually project from lower part (arms forming long ridges for most of length of style head in Mandevilla and Macrosiphonia) to which anthers are attached; stigmatic zone confined to re gion on underside or lower region of style head.