Gethyllis and Apodolirion are two unifloral genera with fused spathe bracts that retain the ovary inside the bulbs until the fruit matures.

[2] Gethyllis was one of the two Hamantheae genera to be described (Linnaeus 1753),[4] and in 1829 Dumortier placed it in a monotypic higher taxon, tribe Gethyllideae,[1] and hence is given as the authority, a practice followed by Salisbury.

[8] Traub recognised the distinct features of these two genera, for which he created the tribe Gethylleae in his 1963 monograph on the Amaryllidaceae, based on the type genus Gethyllis.

[10] Later molecular phylogenetic research has shown that these two genera, while forming a monophyletic subclade, is situated as one of three subtribes of Haemantheae, since forming a separate tribe renders Haemantheae paraphyletic.

Although the two genera are resolved in this process as distinct sister groups, the possibility that they may eventually be considered a single genus remains.