26 GRASSES OF IOWA. 



ate-pointed, hyaline. Tall, erect, perennials, with usually simple culms, 

 long leaves, and ample terminal panicles ; the small spikelets surrounded 

 by long silky hairs. Allied to Erianthus. 



Species 12, chiefly in the tropics of the Old World; one species culti- 

 vated. 



Saccharutn officinarum is cultivated in tropical countries, and in 

 the southern states along the gulf coast. Occasionally cultivated in 

 greenhouses in Iowa. 



4. ANDROPOGON. 



Andropogon. L. Sp. PI. 1045. 1753. Endlicher Gen. PI. 108. 

 Bentham & Hooker. Gen. PI. 3: 1133, 1135. Hackel in Engler & Prantl. 

 Nat. Pflanz. Fam. II. 2: 26. Scribner. Bull. U. S. Dept. Agrl. Div. Agros. 

 20: 24. /". IS. 



DESCRIPTION. 



Beard Grass. Spikelets in pairs upon each joint of the slender 

 rachis, spiked or racemed, one of them pedicelled and sterile (stamin- 

 ate, pistillate or neutral) often a mere vestige, the other sessile, one- 

 flowered and fertile ; lower glume the larger, coriaceous and nerved, 

 blunt, the second carinate and acute, the two upper hyaline, the flower- 

 ing glume awned from the tip. Stamens 1-3. Grain free. Coarse, 

 mostly rigid perennials, mostly in sterile or sandy soil; with lateral or 

 terminal spikes commonly clustered or digitate ; the rachis hairy or 

 plumose-bearded, and often the sterile or staminate flowers also, (whence 

 the name composed of two Greek words for man and beard.) 



There are about 200 species, chiefly in warmer parts of North 

 America, Asia and temperate Europe. 



North America has 37 species, chiefly in the western states; south- 

 ern states about 25; western Texas 14; Canada 4; eastern states 8; 

 Rocky Mountains 6. 



Europe has 9 species. 



KEY TO THE SPECIES OF ANDROPOGON. 



Inflorescence of spike-like racemes. 



Racemes single A. scoparius .' 



Racemes in pairs or more. 



Hairs on pedicels and rachis joints copious, equalling them in length, 



awn straight, 4-10 mm. long or wanting A. Hallii." 



Hairs on rachis joints and pedicels sparse and shorter. 

 Spikelets 6-8 mm. long, outer scales mostly smooth. 



—A. provincialis . 3 

 Spikelets 8-10 mm. , outer scales very rough-scabrous. 



— A. TennesseensisS 



