Plants annual. Culms (5)10-30(55) cm tall, usually with 2-4 nodes.
Auricles small but distinct, glabrous; blades 1.5-5.5 mm wide, involute, abaxial (lower) surface glabrous or hairy, adaxial (upper) surface scabrous, often with hairs over the veins.
Inflorescences spikelike, 1-6 cm long, with 4-24(28) nodes, with 2(3,4) spikelets per node; rachis not disarticulating at maturity, terminating in a node.
Spikelets with 2 (3) florets, only the lowest bisexual, the other(s) strongly reduced. Glumes connate at the base, equal, 15-80 mm long, awnlike, divergent from the rachis. Lemmas 5.5-8 mm long, not keeled, scabrous, sometimes hairy, awned, awn (30)60-130 mm long, flattened. Lodicules 2, sometimes with an indistinct lateral lobe, ciliate, especially on the margins. Anthers about 1 mm long.
Caryopses adherent to the lemma and palea.
According to Frederiksen (1986), there is one species, T. caput-medusae with three subspecies in Taeniatherum. The subspecies have sometimes been treated as species.
Taeniatherum is native from Portugal and Morocco east to the Pamirs. It has also become established as a weed in other parts of the world.
Humprhies (1978) recognized only two subspecies, possibly because he scored awn curvature, the primary differentiating character, as a two state character.
Taeniatherum caput-medusae (L.) Nevski
Frederiksen, S. 1986. Revision of Taeniatherum (Poaceae). Nordic Journal of Botany 6: 389-397.