Type. Gleasonia duidana Standi. Bremekamp (Meded. Bot. Mus. Utrecht 141: 361-364. 1957) placed this genus in a separate subfamily Gleasonioideae on the basis of its exalbuminous seeds and large cotyledons of the embryo. He lends great weight to the character of the type of testa cells of the seeds of Gleasonia as differing fundamentally from those of the various other subfamilies of Rubiaceae.