174 



Gramineae 



58. DIPLACHNE Beauv. HamagayaZoku 



Culms sometimes branched; leaf-blades linear, with involute margins; inflorescence a panicle or compound spike; spikelets 

 short-pedicelled, somewhat laterally flattened, narrowly oblong, 3- to 8-flowered, rather densely arranged in 2 rows on the 

 branches, articulate below the florets; glumes membranous, slighdy folded, unequal, 1-nerved, shorter than the lemmas; lemmas 

 oblong, keeled, chartaceous, 3-nerved, 2- to 4-toothed at apex, the midrib often shordy excurrent at apex; callus short; rachilla 



glabrous; palea as long as the lemma, 2-keeled; stamens 3; ovary glabrous; caryopsis free within the lemma and palea. 



Cosmopolitan, with many species in warmer and tropical regions. 



1. Diplachne fusca (L.) Beauv. Festuca fusca L.; 

 Bromus polystachyus Forsk.; Leptochloa fusca (L.) Kunth; D. 

 fascicularis sensu auct. Japon., non Beauv.; Leptochloa jascicu- 

 laris sensu auct. Japon., non A. Gray; D. pojystachya (Forsk.) 

 Backer Hamagaya, Mitsubagaya, Takao-baeengaya. An- 

 nual; culms erect or decumbent, branched at base, 30-60 cm. 

 long; leaf-blades rather flat, 20-30 cm. long, 2-5 mm. wide, 

 glaucous-green; ligules hyaline, 3-4 mm. long, denticulate, 

 smooth, glabrous; panicles 15-25 cm. long, narrowly ovate, 

 rather dense, pale green, sometimes lead-gray, rarely dull red, 

 the branches 5-10 cm. long, numerous, nearly simple; pedicels 



short, appressed to the branch; spikelets lanceolate, 7-10 mm. 

 long, densely 8- to 14-flowered; glumes unequal, broadly lan- 

 ceolate, acuminate, the lower about 2 mm., the upper 3-3.5 

 mm. long; lemmas narrowly oblong, minutely appressed- 

 puberulent on the margin below the middle, the midrib ex- 

 current into an awn 1-2 mm. long; anthers elliptic, about 0.3 

 mm. long; caryopsis lanceolate, biconvex, about 2 mm. long. 



^Near seashores; Honshu (Ise, Totomi, and Kazusa Prov.), 



Kyushu (Chikuzen Prov.) ; rare. Formosa, China, Malaysia, 



India, Australia, and Africa. 



59. LEPTOCHLOA Beauv. Azegaya Zoku 



Annuals or perennials; leaf-blades linear; panicles with an elongate axis and nearly simple branches; spikelets sessile or short- 

 pedicelled, crowded in 2 rows on side of the rachis, 2- to 7-flowered, rather flat, articulate below the florets; florets bisexual; 

 glumes 2, membranous, 1-nerved; lemmas small, membranous, obtuse or nearly so, folded, usually awnless, 3-nerved, appressed- 



puberulent; callus minute; rachilla glabrous; palea 2-keeled; caryopsis smooth, glabrous, ovate, obsoletely rugose. Widespread 



in temperate and warmer regions. 



lA. Leaf-sheaths glabrous; spikelets 5- to 7-flowered, 2.5-3 mm. long; lemmas 1-1.2 mm. long 1. L. chinensis 



IB. Leaf-sheaths sparsely papillose-pilose with long hairs; spikelets 2- or 3-flowered, about 1.5 mm. long; lemmas 0.6—0.8 mm. long. 



2. L. panicea 



1. Leptochloa chinensis (L.) Nees. Poa chinensis L.; 

 L. eragrostoides Steud.; L. tenerrima sensu auct. Japon., non 



Roem. & Schult. Azegaya. Annual; culms ascending 



from branching base, 30-70 cm. long; leaf-blades membranous, 

 green and slightly glaucous, 7-15 cm. long, 3-8 mm. wide, 

 rather flat; ligules about 1 mm. long; panicles at length ex- 

 serted, narrowly ovate, 15-40 cm. long, the branches rather 

 numerous and simple, irregular on the main-axis, spreading, 

 4-10 cm. long, filiform, compressed-triangular, scabrous, spike- 

 let-bearing from near base; spikelets short-pedicelled, appressed 

 or erect, pale green and slighdy reddish; glumes broadly lan- 

 ceolate, acute, the first 1-nerved, 0.7-1 mm. long, the second 

 3-nerved, 1.2-1.5 mm. long; lemmas membranous, 1-1.2 mm. 

 long, obtuse to rather rounded at apex, with sparse, short, ap- 

 pressed hairs; anthers minute, 0.15-0.2 mm. long; caryopsis 

 ellipsoidal, 0.8 mm. long, dorsiventrally slightly compressed, 

 with obsolete, linear-lanceolate areolae caused by minute 



longitudinal striations and short transverse lines connecting 

 them. Aug.-Oct. Honshu, Shikoku, Kyushu; rather com- 

 mon. China, Formosa, Malaysia, India, and Australia. 



2. Leptochloa panicea (Retz.) Ohwi. Poa panicea 



Retz.; L. filiformis sensu auct. Japon., non Beauv. Ito-aze- 



gaya. More slender than the preceding; culms 50-100 cm. 

 long from ascending base; leaf-blades 10-20 cm. long, 3-6 mm. 

 wide, flat, thin, with spreading, long, whitish hairs callose at 

 base; sheaths sparingly long-pilose; ligules hyaline, truncate, 

 0.5-1 mm. long; panicles at length exserted, 20-30 cm. long, 

 the branches spreading, slender, 5-10 cm. long; spikelets about 

 1.5 mm. long, rather flat; glumes unequal, 1-nerved, mem- 

 branous, broadly lanceolate, 0.7-1 mm. long; lemmas ovate, 

 0.6-0.8 mm. long, white puberulent; anthers about 0.1 mm. 

 long, elliptic; caryopsis ovoid, obsoletely rugulose, about 0.5 

 mm. long. Kyushu; rather rare. Ryukyus, China, For- 

 mosa, and tropical Asia. 



60. TRIPOGON Roth Torikogusa Zoku 



Densely tufted perennials; leaf-blades very narrow, often filiform with involute margins; culms slender, often delicate; in- 

 florescence a simple terminal spike; spikelets somewhat flattened laterally, in 2 rows on one side of the axis, nearly sessile, 3- to 

 10-flowered, jointed below the florets; glumes 2, unequal, 1-nerved or the upper 3-nerved, narrow, rather membranous; lemmas 

 3-nerved, thinly chartaceous, narrow, truncate, keeled, the midrib excurrent into a straight or geniculate awn, the lateral nerves 

 ending in a short tooth or mucro; callus obtuse, short-hairy; rachilla glabrous; palea as long as the lemma, 2-keeled; stamens 3; 

 caryopsis glabrous. With more than a dozen species in warm regions. 



lA. Glumes 1-nerved; lemma with a geniculate awn extending from the midrib; anthers 1-1.5 mm. long 1. T. japonicus 



IB. Glumes unequal, the first 1-nerved, the second 3-nerved; lemma with a short straight awn extending from the midrib; anthers 0.7—1 

 mm. long 2. T. chinensis var. coreensis 



