PANICUM.] GRAMINEJS. 425 



strongly nerved. Fl. glume nerved, hardening and enclosing the palea 

 and fruit. Scales 2, fleshy, truncate. Stamens 3, Ovary glabrous ; stig- 

 mas penicillate, shorter than the style. Fruit compressed or plano-convex. 

 DISTRIB. Chiefly tropical ; species 500. ETYM. The Latin name. 

 SUB-GEN. 1. Digitar'ia, Scop. (gen.). Spikelets unilateral, on digitate 

 spikes. Flowering glume not awiied. 



1. P. gla'brum, Gaud.; spikes about 3, spikelets 1-fld. Digitaria 

 humifusa, Pers. 



Sandy soil in the S.E. counties, from Norfolk to Hampshire, local; a native 

 or colonist, Watson; fl. July- Aug. Annual. Root fibrous. Stems 6-12 in., 

 prostrate or decumbent. Leaves narrow, flat ; sheaths flat, mouth hairy ; 

 ligule short. Spikes 2-Z in. , flexuous, channelled on the face. Spikelets -, 1 , 

 in., in pedi celled pairs, plano-convex, elliptic, purplish ; empty glumes 

 hairy, lower minute appressed or 0. DISTKIB. Most warm climates. 



SUB-GEN. 2. EcMnochlo'a, Beauv. (gen.). Spikelets in racemes or pani- 

 cles. Flowering glume a'.vned or pointed. 

 P. CRUS-GAL'LI, L. ; spikelets panicled 1-fld. 



Fields and waste places in the S.E. of England ; naturalized ; fl. July. 

 Annual. Stems 1-4 ft., stout, ascending. Leaves % in. diam., flat, gla- 

 brous ; edges rough, often waved ; ligule 0. Panicle 3-6 in. ; branches 

 subunilateral ; rachis 3-quetrous, pubescent ; pedicel hairy. Spikelets I in., 

 plano-convex, greenish ; upper empty glume hispid, pointed or rigidly 

 awned ; fl. glume polished. DISTRIB. All temp, and trop. regions. 



2. SETAR IA, Beauv. 

 Sjn'kelets in a dense cylindric spikelike panicle, as in Panicum, but 



awnless, and with stont rough bristles at the base on one side. DISTRIB. 



All warm and trop. regions ; species 20. ETYM. seta, a bristle. 

 1. S. vir'idis, Beauv. ; bristles clustered scabrid. 



Cultivated fields in Norfolk, Suffolk, and Surrey ; a colonist or native, Watson; 

 fl. July-Aug. Annual. Stems suberect, scaberulous above. Leaves flat, 

 smooth, edges rough ; sheaths smooth, edges ciliate ; mouth with a ring of 

 hairs. Panicle 1-3 in., green ; branches whorled, hispid, 3-quetrous ; 

 bristles J-^ in., flexuous, purplish. Spikelets -fa in., elliptic, obtuse ; empty 

 glumes membranous ; fl. glumes shining, punctulate, striate. DISTRIB. All 

 warm climates ; introd. in America. 



S. VERTICILLA'TA, Beauv. ; bristles single or in pairs barbed. 

 Cultivated fields, Norwich, Surrey, and Middlesex ; fl. July-Aug. Habit of 

 S. viridis, but panicle usually narrower, and the bristles truly barbed, their 

 asperities pointing downwards. DISTRIB. As of S. viridis. 



3. NAR'DUS, L. MAT- WEED. 



Spikelets solitary, sessile, secund, in a simple unilateral spike, placed 

 obliquely and in excavations of the slender rachis, 1-fld. Empty 

 glumes 0. Fl. glume 1, slender, concave, keeled, shortly awned, per- 

 sistent. PaleM linear, entire, 2-keeled. Scales 0. Stamens 3. Ovary 

 narrow, glabrous, contracted into a slender style, stigma filiform hairy 



