38 POACEAE. 



28. DACTYLOCTENIUM Willd. Enum. Hort. Berol. 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, referring 

 to the digitately spreading spikes.] A monotypic genus of the warmer parts 

 of the Old World. 



1. Dactyloctenium aegyptium (L.) Willd. Enum. Hort. Berol. 1029. 1809. 

 Cynosurus aegyptius L. Sp. PI. 72. 1753. 



Culms 1.5-6 dm., long, usually decumbent and extensively creeping at the 

 base. Sheaths loose, overlapping and often crowded, smooth and glabrous; 

 leaves 1.5 dm. in length or less, 2-6 mm. wide, smooth or rough, sometimes 

 pubescent, ciliate toward the base; spikes in pairs, or 3-5 and digitate, 1.25-5 

 cm. long; spikelets 3-5-flowered ; scales compressed, scabrous on the keel, the 

 second awned, the flowering ones broader and pointed. 



Waste places, New Providence, Eleuthera, Great Bahama, Fortune Island, Caicos 

 Islands, and Inagua : New York to California, Florida and Texas : common as a 

 weed in the West Indies, in tropical America, and in the tropics of the Old World. 

 EGYPTIAN GRASS. 



29. LEPTOCHLOA Beauv. Agrost. 71, pi. 15, f. 1. 1812. 



Usually tall annual or perennial grasses, with flat leaves and numerous 

 spikes forming a simple panicle. Spikelets usually several-flowered, flattened, 

 alternating in two rows on one side of the rachis. Scales 4 to many; the 2 

 lower empty, keeled, shorter than the spikelet; the flowering 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 warmer regions of both hemispheres. 

 Type species : Cynosurus virgatus L. 



Spikelets with 7 or 8 scales, the flowering scales awnless, or sometimes the first 

 and rarely the second short-awned ; leaves glabrous. 1. L. virgatu. 



Spikelets with 5 or 6 scales, the flowering scales all awned, 

 the awn of the first scale more than one-half as long as the 

 body ; leaves sparingly pilose. 2. L. domingensis. 



1. Leptochloa virgata (L.) Beauv. Agrost. 71, 166. 1812. 

 Cynosurus virgatus L. Syst. Nat. ed. 10, 876. 1759. 



Perennial; culms rather slender, smooth, erect or decumbent, somewhat 

 tufted, 2-10 dm. high, little branched or simple. Leaves glabrous, the blades 

 6-18 cm. long, 4-15 mm. wide ; spikes slender, weak, 3-12 cm. long, racemose 

 near the top of the culm; spikelets about 4 mm. long; flowering scales awn- 

 less or very short-awned. 



New Providence : West Indies and tropical continental America. VIRGATE 

 LEPTOCHLOA. 



