Pennisetum flaccidum Griseb., Nachr. Königl. Ges. Wiss.

Kim, Chang-Seok, Lee, Jeongran, Lee, In-Yong & Han, Young-Woo, 2013, A newly naturalized species in Korea, Pennisetum flaccidum Griseb. (Poaceae), Journal of Species Research 2 (2), pp. 223-226 : 224-226

Pennisetum flaccidum Griseb., Nachr. Königl. Ges. Wiss. Georg-Augusts-Univ. 3: 86, 1868.

Gymnotrix flaccida (Griseb.) Munro ex Aitch., Cat. Pl.

Punjab Sindh: 163, 1869.

Cenchrus flaccidus (Griseb.) Morrone, Ann. Bot. (Oxford) 106: 128, 2010.

Pennisetum mongolicum Franch. ex Roshev. in B.A. Fedchenko, Fl. Asiat. Ross. 6: 77, 1914, pro syn.

mm

A B C D

Pennisetum centrasiaticum var. qinghaiense Y.H. Wu, Acta Bot. Boreal. -Occid. Sin. 24: 1117, 2004.

Perennial; rhizomatous. Culms tufted and erect; up to 120 cm tall. Leaf sheaths loose, glabrous, margins ciliate, imbricate at base; leaf blades linear with a distinct white midrib, 34-45 cm long, 4-14 mm wide, glabrous, acuminate; ligule 1-2 mm. Inflorescences panicles, terminal, linear, straight or slightly flexuous, loose to moderately dense, 4-22 cm long, 12-28 mm wide; rachises glabrous, scaberulous, bearing deciduous spikelet clusters; bristles numerous, usually pale green, occasionally purple-tinged, soft, slender, primary bristles 12-22 mm long, distinguishably longer than other bristles. Spikelet narrowly ovate-oblong, 4-7 mm; pedicels sessile to subsessile; lower glume usually 1/4 spikelet length or less; upper glume 1/3-2/3 spikelet length, 1-3-veined, acuminate; lower floret staminate, lemma as long as spikelet, 3-5- veined, acuminate-rostrate, palea fully developed; upper lemma acuminate, 5-veined. Anthers 3. Fl. and fr. Jul- Oct.

Common name: Himalayan Fountain Grass, Flaccigrass Korean name: Ga-Neun-Soo-Keu-Ryung (ñṫ÷ĩậ).

Habitats. Hillsides, field margins, roadsides on dry sandy soils, sometimes also on slightly saline alluvial soils on flood plains.

Distribution. Central Asia, Western Asia, China, India, Himalayas westward to Afghanistan.

Specimens examined. Yeobangri, Gunsan-si, Jeonrabuk-do, N 36̊ 00′20.63′′, E 126̊ 47′35.88′′, 30 Aug 2012. C. S. Kim and Y. W. Han (3 sheets, HCCN). Ladak ,

Tibet, India, 1868. T. Thomson (Isotype, image data, Royal Botanic Garden , Edinburgh, UK) .

Pennisetum flaccidum is native to Central Asia ( Allen and Hall, 2007). This is a widespread and rather variable species having tough and spreading rhizomes, a glabrous inflorescence axis, and involucres of soft bristles ( Chen and Phillips, 2006). Although the species produce a few viable seeds, its intensive vegetative reproduction system makes the species potentially invasive in many non-native countries ( Szczesniak, 2011). However, this species is cultivated primarily as an ornamental purpose and good for a forage in some countries because of characteristics of frost and drought resistance ( Chen and Phillips, 2006; Allen and Hall, 2007).

In Korea, it was first found at the roadside of a provincial road near Gunsan IC, Gunsan, Jeonrabuk-do. Many individuals of the species were distributed for about 100 m along a roadside. It could be rapidly spread out to adjacent areas because of its intensive vegetative reproductive system. The occurrence of this species in Korea is probably the result of an accidental introduction.

The species is distinguished from P. alopecuroides var. alopecuroides by subsessile involucres and plumose bristles. Korean name, ‘Ga-Neun-Soo-Keu-Ryung’ was given based on thinner inflorescences than those of P. alopecuroides var. alopecuroides (Soo-Keu-Ryung).