Odontadenia macrantha is a vine of the family Apocynaceae native to Central and South America.

Flowering takes place all year, with a peak from December to August, while fruiting peaks from April to October; the smooth seed pods are 20–26 centimetres (7.9–10.2 in) long by 3.5–4.5 centimetres (1.4–1.8 in) wide.

[1] It was originally described as Echites macrantha by Austrian botanists Johann Jacob Roemer and Josef August Schultes in 1819 from material from Brazil.

[3] The species name is derived from the Ancient Greek words makros "long" and anther "flower(ing)".

Odontadenia sylvestris, described by Brazil as distinct on a similar basis, is also regarded as a variant of O.