Agrostis gigantea Roth

This is a widespread and polymorphic species, introduced for pasture or adventive in Australia, North America, and elsewhere. The name Agrostis alba Linnaeus has sometimes been used for this species, but the correct application of that name is uncertain.

Agrostis gigantea, A. capillaris, and A. stolonifera are closely related, widespread weeds, which sometimes hybridize. While the lemma is usually awnless, a small awnlet from at or near the apex may be present in some spikelets.

Very similar to Agrostis stolonifera but distinguished by its rhizomes and lack of stolons and a panicle that remains loose and open after anthesis. It is a more aggressive species than Agrostis stolonifera and can become a troublesome weed. Male-sterile hybrids between the two species are known.

1500-3000 m.

Perennial, rhizomatous; rhizomes tough, scaly, spreading. Culms loosely tufted, ascending to prostrate at base, rooting and branching from lower nodes, up to 130 cm tall. Leaf sheaths smooth or scaberulous; leaf blades linear, flat, 5–30 cm × 3–10 mm, scabrid, apex acuminate; ligule on tillers 1.5–6 mm, as long as or longer than wide, toothed. Panicle oblong or conical in outline, 8–25 cm, contracted at first, open after anthesis; branches 5 or more per node, spreading, very scabrous, bearing branchlets nearly to base, spikelets clustered at the branch apices. Spikelets 2–3 mm, yellowish green or purplish; glumes elliptic-lanceolate, subequal or lower glume slightly longer, scabrid or pilosulous along upper keel and margins, apex acute; callus hairs 0.2–0.4 mm; lemma 2/3–3/4 spikelet length, glabrous, usually awnless, apex obtuse; palea 1/2–3/4 length of lemma. Anthers 1–1.5 mm. Fl. and fr. summer and autumn.

Rhizomatous perennial without stolons; culms 40-120(-150) cm high, erect or geniculately ascending, rooting and branching from the lower nodes, smooth. Leaf-blades 5-20 cm long, 2-8 mm wide, flat, scabrid; ligule 1.5-6 mm long, blunt. Panicle oblong to ovate, 8-25 cm long, loose and open, the branches clustered, spreading, divided above the naked base; inflated tip of pedicel scabrid. Spikelets 2-3 mm long, breaking up at maturity above the persistent glumes; glumes acute, awnless, rough on the keel; lemma 1.5-2.5 mm long, very blunt, usually awnless, rarely with a short awn from near the tip; palea half to two-thirds the length of the lemma; anthers 1-1.5 mm long.

Europe, Himalaya, temperate Asia.

Distribution: Pakistan (Punjab, N.W.FY., Gilgit & Kashmir); Europe and temper-ate Asia; introduced in North America etc.

2900-4000 m

Fl. & Fr. Per.: July-August.

Moist ground, rough grasslands, as a field weed. Anhui, Gansu, Hebei, Heilongjiang, Henan, Hubei, Jiangsu, Jiangxi, Jilin, Liaoning, Nei Mongol, Ningxia, Qinghai, Shaanxi, Shandong, Shanxi, Sichuan, Xinjiang, Xizang, Yunnan, Zhejiang [Afghanistan, NW India, Japan, Korea, Mongolia, Nepal, Pakistan, Russia; N Africa, SW Asia, Europe].

Agrostis stolonifera Linnaeus var. gigantea (Roth) Koch; A. stolonifera subsp. gigantea (Roth) Maire & Weiler; A. sto-lonifera var. ramosa (S. F. Gray) Veldkamp; Vilfa alba (Linnaeus) P. Beauvois var. ramosa S. F. Gray.