182 



GRAMINEAE. 



56. DACTYLOCTENIUM Willd. Enum. 1029. 1809. 



An annual grass with flat leaves and spicate inflorescence, the spikes in pairs or digitate, 

 Spikelets several-flowered, sessile, closely imbricated in two rows on one side of the rachis- 

 which is extended beyond them into a sharp point. Scales compressed, keeled, the 2 lower 

 and the uppermost ones empty, the others subtending flowers. Stamens 3. Styles distinct, 

 short. Stigmas plumose. Grain free, rugose, loosely enclosed in the scale. [Greek, re- 

 ferring to the digitately spreading spikes.] 



A monotypic genus of the warmer parts of the Old World. 



i. Dactyloctenium Aegyptium (L.) Willd. Eg}-ptian Grass. (Fig. 416. 



Cynosurus Aegypiius L. Sp. PI. 72. 1753. 

 Eleusine Aegyptia Pers. Syn. i: 87. 1805. 

 Dactyloctenium Aegyptiacum Willd. Enum. 1029. 1809. 



Culms 6'-2 long, usually decumbent and exten- 

 sively creeping at the base. Sheaths loose, over- 

 lapping and often crowded, smooth and glabrous; 

 ligule very short; leaves 6' in length or less, i"-3" 

 wide, smooth or rough, sometimes pubescent, 

 ciliate toward the base; spikes in pairs, or 3-5 and 

 digitate, ^'-2' long; spikelets 3~5-flowered; scales 

 compressed, scabrous on the keel, the second 

 awned, the flowering ones broader and pointed. 



In waste places and cultivated ground, southern 

 New York, Pennsylvania and Virginia to Illinois and 

 California, south to Florida and Mexico. Widely dis- 

 tributed in tropical America. Naturalized from Asia 

 or Africa. July-Oct 



57. LEPTOCHLOA Beauv. Agrost. 71. pi 15. f. i. 1812. 



Usually tall annual grasses, with flat leaves and numerous spikes forming a simple pan- 

 icle. Spikelets usually 2-many-flowered, flattened, alternating in two rows on one side of 

 the rachis. Scales 4-many; the 2 lower empty, keeled, shorter than the spikelet; the flower- 

 ing scales keeled, 3-nerved. Palet 2-nerved. Stamens 3. Styles distinct. Stigmas plumose. 

 Grain free, enclosed in the scale and palet. [Greek, in allusion to the slender spikes.] 



About 12 species, natives of the wanner regions of both hemispheres. Besides the following r 

 3 others occur in the southern United States. 



i. Leptochloa mucronata (Michx. ) 



Kunth. Northern Leptochloa. 



(Fig. 417.) 



Eleusine mucronata Michx. Fl. Bor. Am. i: 65. 1803- 

 Leptochloa mucronata Kunth, Gram. 1:91. 1829-35. 



Culms i-3 tall, erect, branched, smooth and 

 glabrous. Sheaths shorter than the internodes, 

 smooth and glabrous; Hgule short, lacerate-toothed- 

 leaves 2 / -8 / long, i // -3 // wide, scabrous; spikes 

 numerous, slender, rigid, spreading or ascending, 

 the lower 2'-6' long; spikelets usually 3-flowered, 

 about i" long, the empty scales shorter than the 

 spikelet, acute, i -nerved, slightly scabrous on the 

 keel; flowering scales 2- toothed at the apex, 

 ciliate on the nerves. 



In dry or moist soil, Virginia to Illinois, Missouri 

 and California, south to North Carolina, Louisiana 

 and Mexico. Also in Cuba. July-Sept. 



