100. Hordeum Linnaeus, Sp. Pl. 1: 84. 1753.
大麦属 da mai shu
Plants annual or perennial. Culms usually erect. Leaf sheath of cauline leaves split almost to base; ligule membranous or leathery-membranous; auricles present or absent; leaf blade usually flat. Spike dense, usually without a terminal spikelet; rachis short, brittle, rarely flexible. Spikelets usually 3 per node, in regular rows, with 1(or 2) florets; lateral spikelets usually pedicellate, rarely sessile, often reduced and much smaller than central spikelet; central spikelet usually sessile, rarely pedicellate, perfect. Glumes narrow, subulate-setaceous, sometimes lanceolate dilated at base, inconspicuously 1–3-veined, not keeled. Lemma subrounded abaxially, leathery, rarely leathery-membranous, 5-veined, not keeled, awned or awnless. Palea almost equaling lemma, glabrous, scabrous, or ciliate along keels. Lodicules broadly lanceolate or lanceolate-ovate. Caryopsis usually adnate to lemma and palea, rarely free, oblong, concave furrowed on inner side, apex hairy. x = 7.
Between 30 and 40 species: temperate regions, also on subtropical mountains; ten species (one endemic, two introduced) in China.
In addition to the species treated below, Hordeum bulbosum Linnaeus has been recorded as cultivated in China (FRPS 9(3):30. 1987).
All species when young are used for forage.