Rotundanthus fulvidus is a species of flowering plant in the dogbane family, Apocynaceae.

It is the sole species in genus Rotundanthus.

It is a liana native to southeastern Mexico and Central America, ranging from the Mexican state of Chiapas to Guatemala, Belize, Honduras, Nicaragua, and Costa Rica.

[1] The species was first described as Gonolobus fulvidus by Francis Ballard in 1940.

In 2015 Gilberto N. Morillo renamed it Rotundanthus fulvidus, placing it in its own monotypic genus.