HABIT Annual. Culms geniculately ascending (1), or decumbent (2), or rambling (1); slender (1/1); 18-41.33-80 cm long; wiry; rooting from lower nodes. Lateral branches sparse (1/1). Ligule an eciliate membrane (2), or a ciliolate membrane (1). Leaf-blades linear (1), or lanceolate (2); flaccid. INFLORESCENCE Synflorescence compound; scanty (1), or fasciculate (2). Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; enclosed. Spatheole lanceolate; membranous. Racemes single; bearing few fertile spikelets; bearing 2 fertile spikelets on each. Rhachis fragile at the nodes. Rhachis internodes linear. Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear. STERILE SPIKELETS Companion sterile spikelets well-developed; separately deciduous. Companion sterile spikelet callus oblong. Companion sterile spikelet glumes muticous. FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 3-3.5-4 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pilose; base obtuse; attached obliquely. GLUMES Glumes exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; cartilaginous; without keels. Lower glume surface smooth (2), or asperulous (1); glabrous (2), or hispidulous (1). Upper glume oblong; 1-keeled. FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline; 0 -veined. Fertile lemma oblong. Lemma apex awned; 1 -awned. Principal lemma awn geniculate. Palea absent or minute. DISTRIBUTION Temperate Asia (1), or Tropical Asia.