INDIAN GRASS. 149 



PURPLE WOOD GRASS, BROOM GRASS (Andropogon 

 sco2}arius), is found on sterile, sandy soils, flowering 

 from July to September. It grows from two to four 

 feet high, with many-branched panicles ; lower sheaths 

 an'd narrow leaves hairy; spikes mostly single, very loose, 

 slender, slightly silky, with dull, white hairs ; rachis zig- 

 zag, hairy along the edges. 



SILVER BEARD GRASS (Andropogon argenteus) grows 

 about three feet high, with spikes in pairs, on peduncles 

 exceeding the sheaths, dense, and very silky. Common 

 on sterile, sandy soils, in Virginia and southward, flow- 

 ering in September and October. 



VIRGINIAN BEARD GRASS (Andropogon Virginicus) 

 grows on similar soils to the last, from New York to 

 Illinois, and southward. Stem flattish below ; slender, 

 short-branched above ; sheaths smooth ; spikes soft, 

 two or three in distant clusters. 



CLUSTER-FLOWERED BEARD GRASS (Andropogon ma- 

 crourus] is found from New York to Virginia, south- 

 ward on the coast. Stems from two to three feet high, 

 bushy, branched at the summit, with many spikes, form- 

 ing thick, leafy clusters ; sheaths rough, the upper 

 hairy. 



65. SORGHUM. 



Spikelets two or three together, in an open panicle, 

 the lateral ones sterile, middle fertile ; stamens three. 



INDIAN GRASS, WOOD GRASS (Sorghum nutans), is a 

 grass sometimes found on our dry, sterile soils, with a 

 panicle oblong, somewhat compressed, from six to ten 

 inches long ; stem from three to five feet high ; leaves 

 linear, grayish ; sheaths smooth ; spikelets light brown 

 and glossy, drooping when mature ; hairy at the base ; 

 awn twisted. It flowers in August. 

 13* 



