Inflorescence a cylindrical or almost cylindrical spike-like raceme, solitary, subtended by a spathe. Inflorescence a cylindrical or almost cylindrical spike-like raceme, solitary, subtended by a spathe; rachis articulate. Spikelets paired, usually dissimilar, awnless, 1 sessile and 1 pedicellate, sessile and pedicellate spikelets falling together with the adjaceant axis internode. Sessile spikelet sunk in the deeply concave recesses of the rachis; florets 2, the upper bisexual, the lower male or sterile. Glumes 2, the lower papery and closely covering the cavity of the rachis, the upper thinner, often rigid, concave or keeled. Lemmas 2, hyaline; paleas hyaline. Pedicellate spikelet on a closely appressed pedicel, but often spreading, with a male or rarely bisexual floret, or reduced to 1 or 2 empty glumes.
Distribution and occurrence: World: 4 species from the tropics. Australia: 1 species (native).
Derivation: named after C.F. Rottboell.
Text by S. W. L. Jacobs & C. A. Wall