Hooked Bristlegrass

This is an easy species to recognize because of its clinging, retrorsely barbed bristles.

Very similar to Setaria viridis (with which it hybridises), differing mainly in the direction of the barbs on the bristles, and prefering warmer parts of the World. It is eaten by cattle when young, but avoided once the spikes appear.

Annuals; clum usually 20-100 cm high, geniculate. Blade 5-18 mm wide, thin, with nimutely tubercle- based hairs; sheath hairy or glabrous, margins ciciate; ligule a ring of hairs, ca. 1 mm long. Panicle contracted, cylindrical, 2-10 cm long, branches interrupted. Spikelets 1.8-2 mm long, subtended by 1-4 bristles, these 4-16 mm long, flattened in lower part, margins with barb like hairs directed downwards; lower glume ca. 1 mm long; upper glume as long as spikelet, 5-veined; lower lemma equaling spikelet, rarely with a minute lower palea; upper lemma finely and transversely rugose; anther ca.0.7 mm long.

Annual. Culms tufted, much branched, ascending, 20–100 cm tall, glabrous. Leaf sheaths thin, glabrous or papillose-pub-erulous, margins ciliolate; leaf blades broadly linear, flaccid, 5–20 × 0.4–1.8 cm, usually glabrous, base subrounded, margins scabrous, apex long acuminate; ligule 0.5–1 mm. Panicle densely spikelike, or lobed with short lateral branches on vigorous specimens, 4–15 cm, spikelets subtended by 1–4 bristles; axis shortly hispidulous; bristles green or brownish, 3–8 mm, retrorsely barbed and often becoming entangled. Spikelets elliptic, 1.8–2.4 mm, green with obvious darker veins, obtuse; lower glume 1/3–1/2 as long as spikelet, obtuse; upper glume boat-shaped, as long as spikelet, 7-veined; lower floret neuter; lower palea much reduced; upper lemma dorsally compressed, finely rugose. Fl. and fr. Jun–Sep. 2n = 18, 36.

Loosely tufted annual; culms 10-100 cm high or more, geniculately ascending. Leaf-blades broadly linear, 5-30 cm long, 4-16 mm wide, flaccid, glabrous to loosely pilose; sheaths glabrous to pubescent. Panicle spiciform, linear to untidily lobed, 2-15 cm long, often entangled, the rhachis hispidulous; bristles 3-8 mm long, retrorsely barbed, tenaciously clinging. Spikelets ellipsoid, 1.5-2.5 mm long; lower glume one-third to half as long as the spikelet; upper glume as long as the spikelet; lower floret barren, the palea minute; upper lemma finely rugose.

Tropics & temperate regions of Old World, introduced in America.

Tropical and temerate regions of the Old World. Taiwan, common in open and waste places.

Nei Mongol, Taiwan, Yunnan [tropical and warm-temperate regions of the Old World; introduced in America].

Distribution: Pakistan (Sind, Baluchistan, Punjab, N.W.F.P. & Kashmir); tropical and warm temperate regions generally.

300-800 m

Fl. & Fr. Per.: throughout much of the year.

Roadsides, open weedy places; 300–1000 m.

Panicum verticillatum L., Sp. Pl. ed. 2. 82. 1762.

Panicum verticillatum Linnaeus, Sp. Pl., ed. 2, 1: 82. 1762; Chaetochloa brevispica Scribner & Merrill; C. vertici-llata (Linnaeus) Scribner; Chamaeraphis italica (Linnaeus) Kuntze var. verticillata (Linnaeus) Kuntze; C. verticillata (Linnaeus) Porter; Panicum asperum Lamarck; Pennisetum verti-cillatum (Linnaeus) R. Brown; Setaria brevispica (Scribner & Merrill) K. Schumann.