Holcus mollis

Cho, Yanghoon & Lee, Jonghwan Kim and Byoungyoon, 2017, Vascular plants of Poaceae (II) new to Korea: Holcus mollis L. and Aira elegantissima Schur, Journal of Species Research 6 (2), pp. 171-176 : 171-174

1. Holcus mollis L., Syst. Nat. (ed. 10) 2: 1305. 1759.

LT: (LINN-1212.9) LT designated by Cope in Cafferty et al., Taxon 49(2): 251 (2000).

Korean name: Gin-hin-teol-sae (ỨṜnjNj)

Perennial; rhizomatous, creeping to 40-50 cm, forming a dense network near the soil surface. Culms erect or geniculately ascending, usually decumbent at the base, 20-100 cm tall with 4 to 7 bearded nodes, noded; lower internodes glabrous or sparsely pubescent retro-

172 JOURNAL OF SPECIES RESEARCH Vol. 6, No. 2 June 2017 CHO ET AL . - NEWLY RECORDED POACEAE IN KOREA ( II) 173

A B C D E F

A B C D E

versally with node pubescent. Leaves: sheath glabrous or hairy; ligule eciliately membranous, 1-5 mm long, obtuse; blade linear-lanceolate, 4-20 cm long, 3-10 mm wide, surface pubescent at early stage but caducous at age, margins scabrous. Panicles open, oblong, or ovate, loose, 4-10(-20) cm long, 1-3 cm wide; branches pu- berulent or ciliate. Spikelets solitary, elliptic, laterally compressed, 4-6(7) mm long, sterile with sessile or fertile with pedicels, falling entire; pedicels 1-4 mm long, pilose, 0.3 mm long; rhachilla hairy; glumes subequal, exceeding and enclosing the florets, ovate, membranous, whitish green when young, straw-colored with age; lower glume lanceolate, (3.5-) 5-7 mm long, as long as upper glume, chartaceous, 1-keeled, 1-veined with ciliate, surface asperulous, apex acute; upper glume elliptic, (3.5-) 5-7 mm long, 2 times longer than adjacent fertile lemma, chartaceous, 1-keeled, 3-veined with primary vein ciliate, surface asperulous, pubescent, apex acute, mucronate. Floret single per spikelet, internodes elon- gated below; fertile lemma thicker than glume, elliptic, cartilaginous, shiny, (2-) 2.5-3 mm long, keeled above, 5-veined, lateral veins obscure, surface glabrous or pu- berulous, hairy above, apex obtuse; palea as long as lemma. Apical sterile florets 1 in number; male; elliptic; bifid, 2.5-3 mm long; 1-awned; awns subapical; straight; 3.5-5 mm long, exserted. Anthers 3; 1.5-2.5 mm long. Ovary glabrous.

Habitats. Disturbed areas near mountain roadsides.

Distribution. Europe: northern, central, southwestern, southeastern, and eastern. Africa: north and Macarone- sia. Asia-tropical: India. Australasia: Australia and New Zealand.

Specimens examined. Sangcheon-ri, Wicheon-myeon, Geochang-gun , Gyeongsangnam-do N 35°43 ʹ 27.74 ʺ E 127°46 ʹ 46.38 ʺ, 21 Jun. 2014. J. H . Kim and Y. H . Cho 141238 (2 sheets, KB) .

Holcus , a genus of Poaceae , is native to Europe, North Africa, and the Middle East, comprising 10 species ( Lee, 2007). Among members of the genus, two species, H. lanatus L. and H. mollis L. are well known as invasive and troublesome weeds in other continents and thus management controls are needed. In North America, H. lanatus is distributed densely and does not co-exist with other plant species, and thus is controlled for habitat restoration ( DiTomaso and Healy, 2007). In Australia, H. lanatus is thought to be a serious threat to wetland biodiversity and a number of endangered plant commu- nities by densely inhabiting at moist sites such as along watercourses and swamps ( Beddows, 1961). In Korea, H. lanatus have been already introduced and naturalized mostly in southern parts of the Korea peninsula and Jejudo ( Lee et al., 2011; Cho et al., 2016). Another species, H. mollis is native to Europe, the Mediterranean and nearby areas, but the species was naturalized at Australia and North America ( Standley, 2007). In Britain, Holcus mollis is a common and troublesome weed growing in a wide range of moisture and soil conditions ( Hubbard, 1984). In Korea, the grass has been introduced in roadsides of mountain Keumwon-san. The arrival of this grass in such a remote area probably occurred during the development and construction of the forest roads in the 1980’s. Holcus mollis is easily distinguished from the only other member of the genus naturalized in this flora region, H. lanatus L., by the extensive creeping rhizomes (not caespitose), glabrous culm (not villous), a geniculate (not hooked, or curved) awn from the upper lemma and the bearded nodes like hairy knees on the culm.