Brargentina Morillo et H. A. Keller, a new genus of Gonolobinae (Apocynaceae, Asclepiadoideae), segregated from Gyrostelma E. Fourn., is described and illustrated, and two new combinations, Brargentina bornmulleri (Schltr. ex Malme) Morillo et H. A. Keller, and Gyrostelma oxypetaloides var. grazielae (Fontella) Morillo et H. A. Keller, are proposed. A key to identify Brargentina from related genera is also presented.