Plants annual or perennial; synoecious; tufted, cespitose, or sprawling. Culms 2-30 cm. Sheaths open; ligules membranous; blades flat. Inflorescences terminal, racemelike, 1-sided panicles, usually exceeding the upper leaves; branches 0.4-0.8 mm, not appressed to the rachis, with 3 spikelets, bases sharply curved, strigose, axes not extending beyond the distal spikelets; disarticulation at the base of the branches. Spikelets with 1 floret; lateral spikelets pedicellate, staminate or sterile, varying from rudimentary to as large as the central spikelet; central spikelets sessile or pedicellate, laterally compressed, bisexual. Glumes exceeded by the florets, cuneate, truncate to bilobed, 1-veined, awned from the midveins, sometimes also from the lateral lobes; lemmas 3-veined, central veins and sometimes the lateral veins extended into awns, central awns always the longest; paleas almost as long as the lemmas, 2-keeled, 2-awned; lodicules 2; anthers 3; styles 2. Caryopses about twice as large as the embryos; hila punctate. x = 10. Name from the Greek aix, goat, and pogon, beard, alluding to the fascicles of the awns of the spikelets.
