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
Leaves all reduced to tightly sheathing scales on the culm below the inflorescence bracts. Culms slender, rigid, up to 70 cm high. Inflorescence 15–80 mm long. Spikelets few, sessile, on short branches. Glumes acute, with ciliate keels. Nut ovoid, obtuse. Widespread. Swamps and lake sides Baumea juncea
Either leaves with distinct long laminas or reduced to sheathing scales at the base of the culm