Plants perennial; cespitose. Culms 5-150 cm, erect. Sheaths open nearly to the base; auricles absent; ligules about as long as wide, membranous, truncate to rounded, ciliate-erose; blades convolute or involute, adaxial surfaces ribbed over the veins. Inflorescences narrow panicles or racemes; disarticulationabove the glumes and beneath the florets. Spikelets laterally compressed, with (1)2-8 florets; rachillas pilose on all sides, terminating in reduced florets. Glumes equaling or exceeding the adjacent lemmas, exceeded by the distal florets, 1-3(5)-veined; calluses acute, strigose; lemmas pilose or glabrous, 3-5-veined, apices acute, toothed, awned from about midlength, awns geniculate, twisted and terete below the bend; paleas shorter than the lemmas, wings more than 1/2 as wide as the intercostal region; lodicules 2, lobed; anthers 3; ovariespubescent distally. Caryopses with a solid endosperm, longitudinally grooved, with a terminal tuft of hairs; hila more than 1/2 as long as the caryopses, linear. x = 7. Name from the Greek helictos, twisted, and trichon, awn, referring to the lemma awn.
Helictotrichon has about 15 species. Most are native to Europe; one is endemic to the Flora region, and one has been introduced as an ornamental. The genus is sometimes interpreted as including Avenula.
SELECTED REFERENCESGervais, C. 1973. Contribution à l'étude cytologique et taxonomique des avoines vivaces. Denkschr. Schweiz. Naturf. Ges. 88:3-166; Hedberg, I.1961. Chromosome studies in Helictotrichon Bess. Bot. Not. 114:389-396.