Erect annual, 15–50 cm. high or more. Leaf-blades linear, 3–30 cm. long and up to 3.5 mm. wide. Panicle ovate, 7–30 cm. long, open, divaricate. Spikelets purple or purplish-brown; glumes linear-lanceolate, subequal or unequal, distinctly awned (awn up to 2.5 mm. long), puberulous or at least with a scabrid keel; lower glume shorter than the upper, 3.5–6 mm. long; upper glume strongly bidentate, 5–8 mm. long; lemma subterete, 5–7 mm. long, shorter than the glumes, coarsely scabrid in the upper part or at least on the keel, passing into the awn without column or articulation; callus linear, 0.5 mm. long, narrowly obtuse at the tip; awns 1–2 cm. long, scabrid.
Notes
(for species as a whole). Distinguished from A. adscensionis by the awned glumes overtopping the lemma.
