Light green, perennial tufts to 100 cm, with creeping rhizomes. Leaf-sheath glabrous; basal sheaths sometimes reddish purple. Ligule 0.5-2 mm, truncate, ciliate. Leaf-blade 10-16 cm × 4-9 mm, glabrous; margins finely scabrid. Culm erect, internodes glabrous. Panicle 10-20 cm, open or contracted, erect; rachis slightly compressed, scabrid on angles, branches filiform, finely scabrid. Spikelets 15-25 mm, 3-5-flowered, parallel-sided, compressed, brownish green. Glumes unequal, subobtuse, glabrous, keel minutely scabrid near apex; lower 4-4.5 mm, 1-nerved, upper 6-6.5 mm, 3-nerved. Lemma 8-10 mm, 5-7-nerved, rounded, usually glabrous but sometimes finely pubescent at base, apex obtuse, hyaline; awn 0, or rarely 1-2 mm. Palea ≈ lemma. Callus glabrous. Rachilla finely scabrid or with minute hairs. Anthers 4.3-5.5 mm. Caryopsis c. 7.5 × 2 mm. Chasmogamous.