Belongs to the monotypic genus; Subfamily: Periplocoideae; Tribe: Gymnanthereae.

Shrub up to 2 m tall. Leaves verticillate, sometimes decussate. Inflorescences axillary, monochastic-branched cyme, 1-7 flowers. Follicles usually paired; seeds smooth. It differs from other Apocynaceae by its straight and vertical reddish branches and grass-like leaves. Phylogenetically, Ischnolepis forms a robust clade with the Malagasy Apocynaceae Camptocarpus and Pentopetia (Ionta & Judd, 2007).