1Roots present. Budding pouches 2, basal, lateral, one on either side of the axis. Inflorescence developing from one of the budding pouches, consisting of 1 ♀ and 2 ♂ flowers enclosed by a membranous spathe. Anther bilocular, transversely dehiscent. Stipe present. Raphides present.
1'Roots none. Budding pouch 1, median, never giving rise to an inflorescence. Inflorescence 1, dorsal, consisting of a cavity containing 1 ♀ and 1 ♂ flower, without a spathe. Anther unilocular, apically dehiscent. Stipe not visible to the naked eye. Raphides absent.
2Fronds with a dorsal and a ventral scale, one to many roots and 3-15 nerves. Stipe ventrally attached. Brown pigment cells and druses in the parenchyma.
2'Fronds without dorsal and ventral scales, with one root (rarely none) and 1-3, often indistinct nerves. Stipe marginally attached. Brown pigment cells and druses absent.