巨早熟禾 ju zao shu he

Poa juncifolia Scribner, Bull. Div. Agrostol., U.S.D.A. 11: 52. 1898; P. ampla Merrill.

Plants bluish. Perennials, densely tufted, sterile shoots intra- and extravaginal. Culms erect, 40–120 cm tall. Leaf sheath smooth or scabrid, uppermost closed for 1/15–1/5 of length; blade flat or folded, papery to thickly papery, up to 25 cm × 1–3(–4) mm, adaxially scabrid; ligule 0.5–3 mm, abaxially scabrid, truncate to acute, of tillers all truncate, collar glabrous. Panicle narrow, dense, 10–15 × 1–3 cm; branches steeply ascending, scabrid angled, with spikelets from the base. Spikelets narrowly lanceolate, weakly compressed, 8–10 mm, florets 4–7; vivipary absent; glumes broad, subequal, lower glume 3–3.5 mm, upper glume 4–4.5 mm, nearly as long as lower lemma; lemmas weakly keeled, 4–6 mm, apex obtuse to acute, glabrous, abaxially scabrid; callus glabrous; palea keels scabrid. Anthers 1.5–3 mm. Fl. and fr. May–Jul. 2n = 62, 63, 64, 65, 68, 70, 71, 97.

Introduced in China [India, Pakistan; SW Asia (Iran), Australia; native to North and South America].

Poa secunda subsp. juncifolia was introduced to China for forage and rangeland stabilization under the name P. ampla. A few vouchers exist from experimental stations, but whether or not it occurs outside of cultivation in China was not verified. Poa secunda subsp. secunda has acute to acuminate ligules, softer foliage, and crisply puberulent lemma surfaces.