190 



Gramineae 



87. SACCHARUM L. Sato-kibi Zoku 



Usually stout, tufted perennials; culms terete, solid; leaf-blades linear, with a thick midnerve; panicles large, dense, with an 

 elongate axis, pubescent; racemes slender, many-jointed, on numerous branches of panicles; spikelets geminate, one sessile, the 

 other pedicellate, perfect, awnless, disarticulating below the spikelets; callus hairs long; glumes hyaline at tip, the first narrow, 

 the second I- to 5-nerved; sterile lemma hyaline, epaleate; fertile lemma hyaline, obtuse, sometimes reduced; palea minute, 

 nerveless. ^Less than 10 species, in warmer regions of Malaysia, e. Asia, India, and N. Africa. 



1. Saccharum spontaneum L. var. arenicola (Ohwi) 



Ohwi. Saccharum spontaneum sensu auct. Japon., non L. 



Wase-obana. Tufted perennial; culms erect, firm, to 1.5 m. 

 high, 6 mm. in diameter, sheathed at base, long-villous in up- 

 per part; leaf-blades coriaceous, linear, 40-60 cm. long, 4-6 

 mm. wide, gradually long-acuminate, narrowed at base, with 

 recurved margins, glaucous beneath, scabrous on upper sur- 

 face and margins, the midrib thickened toward the base; 



mouth of sheath long-hairy; ligules 1.5-3 mm. long, ciliate, 

 ovate or ovate-deltoid; panicle narrow, erect, about 30 cm. 

 long, the branches erect; racemes many-jointed, the joints 4-6 

 mm. long, sparsely long-hairy toward the apex; pedicels 2-3 

 mm. long; sessile spikelet broadly lanceolate, 4.5-5 mm. long; 



callus with a tuft of silky hairs about 10 mm. long. ^Aug.- 



Sept. Sandy places near seashores; Honshu (s. Kanto and 

 Tokaido Distr.) ; locally common. Ryukyus. 



88. MICROSTEGIUM Nees Ashiboso Zoku 



Slender, branched annuals or perennials, decumbent to ascending at base; leaf -blades thin, lanceolate; inflorescence racemose- 

 corymbose; racemes several, rarely solitary, slender, many-jointed; spikelets geminate, one of them pedicelled, the other sessile or 

 short-pedicelled, lanceolate to narrowly ovate; callus-hairs short; glumes rather coriaceous to herbaceous, the first sometimes 

 with a groove between the 2 keels, the second navicular, with a keel on back; sterile lemma hyaline, sometimes paleate; fertile 

 lemma short, hyaline, bidentate, the awn perfect or imperfect; stamens 1-3. About 30 species, in warmer regions. 



lA. Stamens 2; rachilla-joints slender, glabrous except at both ends; keels of the first glume scaberulous; sterile lemma slightly shorter 

 than the spikelet. 



2 A. One o£ the pair of spikelets sessile, the other pedicelled 1 . M. nudum 



2B. Both of the spikelets pedicelled, the pedicels of different length 2. M. japonicum 



IB. Stamens 3; rachilla-joints usually ciliate on the angles, gradually thickened above; keels of the first glume scabrous above; sterile 

 lemma less than half as long as the spikelet or wanting. 



3A. Cleistogamous spikelets wanting; anthers the same length, linear; spikelets all alike; first glume 2-keeled 3. M. ciliatum 



3B. Cleistogamous spikelets present; anthers of 2 forms, linear in the chasmogamic spikelets, minute in the cleistogamous; chasmogamic 

 spikelets of 2 forms, the pedicelled one compressed laterally, with a keeled first glume 4. M. vimineum var. polystachyum 



1. Microstegium nudum (Trin.) A. Camus. Pollinia 

 nuda Trin.; Leptatherum royleanum Nees; M. mayebaranum 

 Honda; P. arisanensis Hayata Miyama-sasagaya. Slen- 

 der, freely branched perennial without distinct rhizomes; 

 culms 20-40 cm. long, erect from a long decumbent base, the 

 nodes pubescent; leaf-blades 4-8 cm. long, 7-10 mm. wide, 

 glabrous, slightly lustrous; ligules truncate, about 0.5 mm. 

 long; sheaths ciliate; inflorescence exserted, the axis 2-3 cm. 

 long; racemes 4-7, slender, pale green, 4-8 cm. long, the joints 

 6-7 mm. long, very slender, about twice as long as the pedicel, 

 with a tuft of short hairs at apex; spikelets geminate, one of 

 them sessile, the other short-pedicelled, about 4 mm. long, 

 lanceolate, rather acute, minutely scabrous, with a broad, shal- 

 low groove above, and a tuft of short hairs at base; awn deli- 

 cate, 15-20 mm. long, flexuous. Sept.-Oct. Woods in low 



mountains; Honshu (Tokaido Distr. and westw.), Shikoku, 

 Kyushu. Formosa, China, Malaysia, India, and the Cau- 

 casus. 



2. Microstegium japonicum (Miq.) Koidz. Pollinia 



japonica Miq.; P. nuda sensu auct. Japon., non Trin. Sasa- 



gaya. Very slender, glabrous, freely branching perennial 

 without distinct rhizomes; culms smooth, 20-70 cm. long, 

 erect from a decumbent base, the nodes glabrous; leaf -blades 

 thin, flat, broadly lanceolate to narrowly ovate, glabrous, 3-7 

 cm. long, 7-10 mm. wide, abruptly acuminate, acute to 

 rounded at the oblique base; sheaths 2-4 cm. long, the upper- 

 most longest; ligules very short; inflorescence long-exserted; 

 racemes 3 to 6, very slender, spreading to deflexed, sessile, 4-6 

 cm. long, many-jointed, green, the joints 3-5 mm. long, 



scaberulous, with a ring of very short hairs at apex; spikelets 

 geminate, 3 mm. long, alike, broadly lanceolate, acute, with a 

 tuft of short hairs at base, the pedicels 1-1.5 mm. and 2.5-3 

 mm. long, respectively; first glume scaberulous, with a broad, 

 shallow groove between the 2 slender keels above, the second 

 as long, 3-nerved, rather acute; fertile lemma about 2 mm. 

 long, with a delicate, minutely scaberulous, flexuous awn 6-8 

 mm. long; anthers 2. Aug.-Oct. Woods in low moun- 

 tains; Hokkaido, Honshu, Shikoku, Kyushu; common. 



s. Korea and China. 



Var. boreale (Ohwi) Ohwi. M. boreale Ohwi Kita- 



sasagaya. Culm-nodes short-pubescent. Shaded places in 



mountains; Hokkaido, Honshu (centr. distr. and northw.). 



3. Microstegium ciliatum (Trin.) A. Camus. Pollinia 

 ciliata Trin.; P. ciliata subsp. wallichiana (Nees) Hack.; 



P. wallichiana Nees O-sasagaya. Culms long-decumbent 



and rooting at base, freely branched, slender, 50-80 cm. long, 

 green, glabrous; leaf-blades flat, broadly linear, 5-8 cm. long, 

 4-7 mm. wide, sparsely pilose above, glabrous beneath, nar- 

 rowed at base; ligules ovate-deltoid, obtuse, reddish brown, 

 hyaline, glabrous, 2-3 mm. long; sheaths glabrous, often with 

 a few long hairs near apex; inflorescence exserted, the axis 

 1-3 cm. long; racemes 4-7, ascending, slender, pale green with 

 a brown hue, 7-10 cm. long, rather densely flowered; rachis 

 joints subterete, 3-4 mm. long, reddish brown ciliate, slighdy 

 thickened above; pedicels about half as long as the joint; 

 spikelets lanceolate, about 3.5 mm. long, those with pedicels 

 barely smaller than the sessile ones; first glume with a distinct 

 groove between the ciliate keels, second glume awn-pointed; 



