金色狗尾草 jin se gou wei cao

Panicum pumilum Poiret in Lamarck, Encycl., Suppl. 4: 273. 1816; Setaria glauca (Linnaeus) P. Beauvois var. dura (I. C. Chung) I. C. Chung; S. lutescens (Weigel ex Stuntz) F. T. Hubbard var. dura I. C. Chung.

Annual. Culms erect or geniculate, 20–90 cm tall, smooth or scabrous just below inflorescence, nodes glabrous. Leaf sheaths keeled, glabrous; leaf blades linear, 5–40 × 0.2–1 cm, abaxial surface smooth, adaxial surface scabrous or pilose at base; ligule ca. 1 mm. Panicle densely cylindrical, 3–17 × 0.4–0.8 cm; branches reduced to a single mature spikelet subtended by 5–10 or more bristles (sometimes an aborted spikelet also present); axis pubescent; bristles gold, brownish gold or sometimes purple, 2–3 times spikelet length. Spikelets broadly ovate, (2.2–)2.5–3.5 mm; glumes ovate; lower glume 1/3–1/2 as long as spikelet; upper glume 1/2–2/3 as long as spikelet; lower floret usually staminate; lower palea hyaline, ovate, matching the upper floret in size and shape, keels narrowly winged; upper lemma broadly ovate, coarsely rugose. Fl. and fr. Jun–Oct. 2n = 18, 36.

Waste places, mountain slopes, roadsides, forest margins. Anhui, Beijing, Fujian, Guangdong, Guizhou, Hainan, Heilongjiang, Henan, Hubei, Hunan, Jiangxi, Ningxia, Shaanxi, Shandong, Shanghai, Sichuan, Taiwan, Xinjiang, Xizang, Yunnan, Zhejiang [originally from temperate and subtropical Asia and Europe, but now widespread].

The name Setaria glauca (Linnaeus) P. Beauvois has been misapplied to this species.

Setaria pumila and S. parviflora are different facets of the same polymorphic complex, and are sometimes regarded as a single, variable species. No character taken on its own is reliable for separating the two species, but the combination of all characters listed in the key will enable most specimens to be assigned to one or the other.

The name Setaria lutescens var. dura refers to a form with the lower lemma hardened and rugose like the upper lemma. This is a rare variant, known from Fujian and Yunnan and also from Korea. Hardening of the lower floret is known to occur occasionally in other genera of Paniceae.

This species is cultivated for forage.