Baumea Gaudich.

Nut surmounted by the thickened stylar base scarcely half as long as the body or almost obsolete. Lowermost flower perfect Baumea
Leaves terete or compressed and more than 2 mm wide or even reduced to the sheaths
Either leaves with distinct long laminas or reduced to sheathing scales at the base of the culm
Nut brown, obtusely 3-angular
Either leaves not septate or if septate then the spaces filled with looser tissue (subseptate)
Spikelets at maturity scarcely clustered, arranged on a zigzag ultimate rhachis which is usually visible between them
Spikelets at maturity clustered and obscuring the ultimate rhachis