Calyx and corolla gamopetalous or polypetalous and sometimes not well differentiated, rotate, campanulate, urceolate, or tubular.
Calyx lobes, [+-] persistent; corolla sympetalous, urceolate, glabrous.
Calyx lobes small, persistent; corolla sympetalous, urceolate, with long unicellular hairs on the inside, the lobes small.
Calyx lobes l-4(-5), or lacking, variable in size, persistent; corolla sympetalous, urceolate, cylindric, or campanulate, the lobes [+ or -] small, usually persistent.
Calyx lobes variable in size, withering persistent or persistent; corolla sympetalous or choripetalous, rotate to urceolate, campanulate, the lobes small to large.
Calyx lobes usually 4 or 5, variable in size, usually persistent, sometimes fleshy; corolla usually sympetalous, urceolate to cylindrical or campanulate, deciduous, with the usually 4 or 5 lobes small to less commonly large.
Calyx lobes small, persistent; corolla sympetalous, [+ or -] urceolate, the lobes small; stamens 10, the filaments straight, unicellular-pubescent, lacking spurs; anthers slightly roughened, with a white deposit of disintegration tissue dorsally, dehiscing by terminal, slitlike pores.
Corolla rotate to variously tubular (urceolate
to cylindrical; e.g., Ceropegia, Echidnopsis, Stapeliopsis), often fleshy, frequently with fleshy annulus around mouth of tube, often ornamented with papillae, hairs, or cilia; lobes with valvate aestivation, sometimes remaining fused at apices; corolline corona rarely present in sinuses of corolla lobes (Leptadenia).