Murainagrass

Annuals or (in ours) perennials. Inflorescence terminal or axillary, of paired (occasionally single or digitate) racemes; racemes interlocked back to back, thereby simulating a single raceme, lacking homogamous pairs and usually exserted, but sometimes enclosed within, a spatheole; internodes and pedicels clavate to inflated, usually exposed on the back of the raceme as a U- or V-shaped segment. Sessile spikelet dorsally flattened; callus obtuse, inserted in the concave top of the internode; lower glume chartaceous to coriaceous, convex (concave in I. afrum), 2-keeled or rounded on the back, entire or 2-lobed; upper glume with or without an awn; lower floret male; upper lemma 2-fid with a glabrous awn from the sinus. Similar in appearance to Andropogon, Ischaemum may technically be separated by the male lower floret and the U-shaped appearance of the internode and pedicel.