1.	Staminal filaments inserted at the mouth of the perianth tube, erect and exserted at base, then arching inwards, the anthers held at the level of the tube mouth, or just inside	2
	Staminal filaments inserted deep inside the perianth tube, or (Thismia) in the throat, but filaments never erect or arching near the mouth, anthers held inside the tube	4
2.	Stamens 6, annulus absent; anthers lacking a flat elliptic connective from which the thecae depend	3
	Stamens 3, annulus lamellae present; anther thecae depending from a flat elliptic connective. Africa and Japan	Oxygyne
3.	Inflorescences aerial, with multiple branches and flowers; India	Haplothismia
	Inflorescences at ground level, usually 1-flowered; Ecuador	Tiputinia
4.	Annulus inserted deep inside the perianth tube; stamens inserted below the annulus; anthers adnate to stigma; rhizomes with clusters of spherical tubers. Continental Africa	Afrothismia
	Annulus inserted at mouth of perianth tube; staminal filaments adjacent to annulus; anthers free, not touching stigma; rhizomes tuberous or not, but never with clusters of spherical bulbils. Americas, Asia-Australasia	Thismia