Plants perennial; tufted or not, extensively rhizomatous, tuftes dense to loose, shoots solitary or clustered, green or violaceous; tillers mainly extravaginal or evenly extra-- and intravaginal, cataphylls present. Culms 5--70(100). erect or bases decumbent, not branching above the base, terete or weakly compressed; nodes terete or weakly compressed, 1--2(3) nodes exposed, proximal node (s) usually not exposed. Sheaths terete to slightly compressed, basal most sheaths, bulb absent, glabrous or infrequently sparsely to moderately pubescent, bases of basal sheaths glabrous, closed 1/4--1/2 their length, distal sheaths 1.2--5(6.2) x long as their blades; collars smooth, glabrous; ligules 0.9--2(3.1) mm, smooth or scabrous, apices truncate to rounded, infrequently obtuse, ciliolate or glabrous; cauline blades 0.4--4.5 mm wide, flat or folded, to involute on the margins, soft and lax to moderately firm, abaxially smooth, glabrous, adaxially smooth or sparsely scabrous, frequently with sparse, slender, erect to appressed, curving, sinuous or strait hairs to 0,2--0,8 mm long, broadly prow-tipped or some narrowly prow-tipped; blades subequal, or middle blades longest, uppermost blades 1.5--10 cm. sterile shoot blades of extravaginal shoots like those of the culm, of intravaginal shoots, when present, sometimes distinctly narrower (0.4--1 mm wide), flat to involute. Panicles 2--15(20) cm, narrowly ovoid to narrowly or broadly pyramidal, loosely contacted to open, sparse to moderately congested, with (25)30 to over 100 spikelets; axis with (1)2--7(9) branches per node; branches spreading early or late, terete or angled, smooth or sparsely to moderately densely scabrous, (1)2--9 cm, with 4--30(50) spikelets, spikelets usually fairly crowded in distal 1/2. Spikelets 3.5--6(7) mm long, to 3.5 x long as wide, laterally compressed, not bulbiferous (sometimes bulbiferous in arctic); florets 2--5, infrequently bulbous basally and leaf-like distally; rachilla internodes mostly less than 1 mm, smooth, glabrous; glumes usually distinctly shorter than the adjacent lemmas, unequal to subequal, narrowly lanceolate to lanceolate, infrequently broadly lanceolate, distinctly keeled, keels sparsely to densely, usually moderately, scabrous, infrequently smooth; lower glumes 1.5--4 (4.5) mm, narrowly lanceolate, occasionally sickle shaped and 1--veined, to lanceolate and 3--veined; upper glumes 2--4.5(5) mm, distinctly shorter to nearly equaling lowest lemma, 2--3 mm; calluses webbed, with only a dorsal tuft of hairs only, or with secondary tufts under each marginal vein, hairs wooly, 1/2 to longer than the lemma; lemmas 2--4.3(6) mm, lanceolate, green or strongly purple colored, distinctly keeled, keels and marginal veins long villous, intermediate veins glabrous or infrequently short villous to softly puberulent, between veins glabrous, smooth or finely muriculate, smooth or sparsely scabrous above, intermediate veins prominent, margins narrowly to broadly hyaline, glabrous, apices acute; paleas scabrous, medially sometimes softly puberulent over the keels, intercostal region narrow, glabrous, or rarely very sparsely and minutely hispidulous. anthers infrequently aborted late in development or 1.2--2 mm; caryopses 0.9--2 mm long, trigonous, sulcate, brown. 2n = 28----94 domestic, det. as pratensis 28, 42, 44, 49, 50, 54, 56, 64, ca. 66, 67, 68, 68--69. Genotype: Ph