Plants annual; cespitose. Culms 20-120 cm, erect to decumbent, often rooting at the lower nodes, branching above the bases. Leaves not aromatic; sheaths open; auricles absent; ligules membranous, ciliate. Inflorescences terminal and axillary, solitary, 2-sided rames, these some¬times fascicled and partially enclosed in subtending leaf sheaths at maturity; disarticulation in the rames, beneath the sessile spikelets. Spikelets in heterogamous sessile-pedicellate pairs. Sessile spikelets hemispherical, partly embedded in the rame axes; lower glumes as long as the spikelets, indurate, alveolate, indistinctly 7-11-veined, not keeled, margins involute; upper glumes chartaceous, 3-veined, usually adherent to the rame axes; lower florets sterile; upper florets bisexual; anthers 3. Pedicels adnate to the rame axes, concealed by the sessile spikelets. Pedicellate spikelets as long as or longer than the sessile spikelets, ovate; lower glumes dorsally compressed, 5-9-veined; upper glumes laterally compressed, 5-7-veined; lower florets sterile; upper florets staminate; anthers 3. x = 7 (probably).
Distribution
Puerto Rico, Miss., Tex., La., Md., Mo., Ala., Pacific Islands (Hawaii), Ga., Ariz., Fla., N.Mex.
Discussion
Hackelochloa is treated here as a monospecific genus that is widely distributed in warm regions of the world, often as a weed. Veldkamp et al. (1986) combined it with Coelorachis Brongn., Heteropholis C.E. Hubb., Ratzeburgia Kunth, and Rottboellia formosa R. Br. in Mnesithea Kunth. The traditional treatment for Hackelochloa is retained here.