Description :

• Annual, small, tufted
• Leaf blade expanded or folded, almost filiform; ligule a hyaline, unfringed membrane
• Inflorescence a panicle, open or rarely contracted, primary branches often paired; spikelets solitary, pedicelled
• Spikelet small, shorter than 4 mm, laterally compressed, disarticulating above glumes; glumes persistent, ± equal, similar, ± as long as spikelet, ovate or elliptic, delicately membranous, acute, keeled, 1-nerved, awnless
• Florets 2, bisexual; lemma firmer than glumes, lanceolate or ovate-lanceolate, rounded on back, obscurely 5-nerved, glabrous or hairy with hairs sometimes in tufts, acute, sometimes acuminate, often minutely 2-lobed, dorsally awned from below middle or awnless, awn geniculate or slightly bent, sometimes upper lemma awned and lower awnless; palea slightly shorter than lemma, narrow, 2-lobed, membranous or subhyaline
• Lodicules 2, delicate
• Stamens 3
• Ovary glabrous; styles plumose
• Caryopsis ellipsoid
• x = 7 (polyploidy)

Nomenclature:

• *Aira L.
  • Linnaeus: 63 (1753)
  • Stapf: 463 (1899)
  • Chippindall: 86 (1955)
  • Clayton: 84 (1970)
  • Launert: 79 (1971)
  • Tutin: 227 (1980)
  • Clayton & Renvoize: 131 (1986)
  • Gibbs Russell et al.: 35 (1990)
  • Watson & Dallwitz: 85 (1994)

Distribution & Notes:

• Global : Species 8, Europe and Mediterranean to Iran; most species widespread weeds
• Southern Africa : Species 2, Free State, Drakensberg area of KwaZulu-Natal to southern and southwestern regions of the Cape