38 POACEAE. 



28. DACTYLOCTENIUM Willd. Enum. Hort. Berol. 1029. 1809. 



An annual grass, witli flart leaves and spicate inflorescence, tlie spikes in 

 pairs or digitate. Spikelets several-flowered, sessile, closely imbricated in two 

 rows on one side of the rachis, whicli is extended beyond them into a sharp 

 point. Scales compressed, keeled, the 2 lower and the uppermost ones empty, 

 the others subtending flowers. Sitamens 3. Styles distinct, short. Stigmas 

 plumose. Grain free, rugose, loosely enclosed in the scale. [Greek, referring 

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

 of the Old World. 



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



Cynosurus aegypUus L. Sp. PI. 72. 1753. 



Gulms 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 mrri. 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 Geass. 



29. LEPTOCHLOA B^auv. 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 thaii 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 vir gains L. 



Spikelets with Y or 8 scales, the flowering- scales awnless, or sometimes the first 

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



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. clominffensis. 



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



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



Perennial; culms rather slender, smooth, ereet 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. Vihgate 

 Leptochloa. 



