Erect annual herb. Stem subcircular or quadrangular, pubescent or glabrous, mostly with raised angles. Leaves sessile, narrowly linear, acute mucronate or awned, recurved, 8-10 (-12) in a whorl, 15-20 x 1-2 mm, sparsely hairy-glabrous above, mostly shortly and densely puberulous tomentose beneath. Inflorescence terminal, much branched and many flowered, up to 30 cm or more, usually longer than intemodes of the flowering branch; peduncle 2-3 cm long. Flowers yellow, 3-3.5 mm in diameter, pedicel 3-5 mm long, wiry. Corolla lobes lanceolate, acute or shortly apiculate, glabrous, c. 1.25 mm long. Fruit 1-1.5 mm long, globose, glabrous.