5; see text Gigasiphon is a genus of plants in the family Fabaceae.

The genus is circumscribed is defined by "a long-tubular hypanthium, an arborescent habit, and a calyx divided into two lobes.

"[1] It includes five species native to eastern Africa, Madagascar, the Philippines, New Guinea, and Lesser Sunda Islands.

[2] Gigasiphon comprises the following species:[3][4][2] Note:: Gigasiphon gossweileri is now in the African monotypic genus Tournaya