Neil Snow

Plants annual. Culms (12)20-125 cm, mostly erect, often strongly compressed, branching; internodes hollow. Sheaths glabrous, smooth to scabrous; ligules 1.5-2 mm, membranous, truncate, erose; blades 25-35(50) cm long, 8-16 mm wide, scabrous on both surfaces. Panicles 8-35 cm, with 50-150 racemose branches; branches (2)5-12 cm, lax, sometimes arcuate, lower branches often remaining enclosed in the upper leaf sheaths. Spikelets 3-4.5 mm, usually tightly imbricate, green but straw-colored when dry, with 2-6 florets. Glumes sometimes mucronate; lower glumes 0.8-1.6 mm, narrowly triangular to lanceolate; upper glumes 1.1-2.1 mm, ovate; rachilla internodes not visible between the florets; lemmas 2.1-2.4 mm, lanceolate to narrowly ovate, membranous, sparsely sericeous along the lateral veins, apices acute, unawned; anthers 0.2-0.4 mm. Caryopses 0.8-1.3 mm long, 0.3-0.5 mm wide, elliptic to obovate, depressed obovate in cross section. 2n = 60.

Dinebra scabra is a neotropical species. It is often confused with Dinebra panicoides but it has more, flexuous to arcuate panicle branches, shorter spikelets, and less prominent lemma veins. It may also be confused with Diplachne fusca subsp. uninervia, from which it differs in its acute lemmas, and with Leptochloa virgata, from which it differs in its hollow, flattened culms and the complete lack of lemma awns. Dispite its similarity to species in two other genera, Peterson et. al. (2012) Annals of Botany 109: 1317–1329 found it to be deeply embedded in their expanded interpretation of Dinebra.