Cosmarium protuberans var. semicircularis
Cosmarium protuberans var. elevatum
Cosmarium protuberans var. guyanense
Cosmarium protuberans var. minus
Cosmarium protuberans var. scrobiculatum
Cosmarium protuberans var. sumatranum
Cosmarium protuberans var. transiens
Cosmarium protuberans f. groenbladii