206 SORGHUM. 



3. A. Scoparius (Purple Wood grass, Broom 

 grass). This grass grows from one to three feet high; 

 is found on sterile sandy soils. Flowers from July 

 to September. 



3. A. Argenteus (Silver Beard grass). Stems rather 

 slender, 1 to 3 feet high ; spikes in pairs, on pedun- 

 cles, exceeding the sheaths, dense, and very silky. 



Common on sterile soils in Virginia, and south- 

 ward. 

 Flowers in September and October. 



4. A. Virginicus (Virginia Beard grass). Stem 

 flattish below, slender, 2 to 3 feet high. Sandy soil, - 

 Massachusetts to Virginia, Illinois and southward. 

 Flowers from September to October. 



5. A. Macrorus (Cluster-flowered Beard grass). 

 Stem stout, 2 to 3 feet high, bushy, branched at the 

 summit ; numerous spikes, forming thick, leafy clus- 

 ters. Low and sandy grounds, New York to Virginia, 

 near the coast, and southward. Flowers from Sep- 

 tember to October. 



66. SORGHUM. Broom Cor]^. 

 ge:n"eric character. 



Spikelets 2 to 3 together on the ramifications of an 

 open panicle, the lateral ones sterile or often reduced 

 merely to their pedicels, only the middle or terminal 

 one fertile, its glumes coriaceous or indurated, some- 



