Figure 349 



HOW TO KNOW THE GRASSES 



cluster at the top of the stem. Southeastern states; Texas to California, 

 often on damp, low ground. 



14b. Inflorescence a terminal panicle of numerous racemes; leafy bracts 

 absent from the panicle. Fig. 349. 



SILVER BEARDGRASS Andropogon saccharoides Sw. 



Perennial; tufted; rather bushy; culms 

 60 — 130 cm. tall; foliage usually glabrous, 

 becoming reddish when mature. The long- 

 stalked panicles are silvery white, oblong, 

 7 — 15 cm. long. The rachis joints and 

 pedicels are fringed with long white hairs. 

 Sessile spikelet of each pair about 4 mm. 

 long, the pedicellate one rudimentary. Sil- 

 ver beardgrass and several of its close 

 relatives are valuable forage grasses in 

 parts of the Southwest, but are easily ex- 

 terminated by overgrazing. Prairies and 

 plains, rocky slopes, draws and dry wash- 

 es, often on sandy soil. June — September. 

 Andropogon perforatus Trin. has a small "pinhole" pit in the center 

 of the first glume. Texas and Mexico. 



Andropogon barbinodis Lag. is taller, with a short, fan-shaped pani- 

 cle, with spikelets 5 — 6 mm. long. The nodes of the culms are promi- 

 nently bearded. Oklahoma to California and Mexico. 



15a. Stalked spikelets present, staminate 16 



15b. Stalked spikelets lacking, only the hairy pedicel present. Fig. 350. 

 INDIAN GRASS SorghastTum nutans (L.) Nash 



Perennial; in tufts from short rhizomes; 

 plants 1 — 2.5 m. tall; foliage usually 

 smooth. Panicles narrow and rather dense, 

 15 — 30 cm. long. The panicle has a "gold- 

 and-silver" aspect because of the yellow, 

 5 — 6 mm. long spikelets and the copious 

 white hairs which fringe the rachises and 

 pedicels. The prominent anthers are gold- 

 en yellow. The panicle is made up of 

 short racemes of 1 — 3 joints. Each sessile 

 spikelet is accompanied by a hairy pedi- 

 cel. The racemes break up into individual 

 joints at maturity, each bearing a spikelet 

 and a rachis joint and pedicel. Indian 

 grass is one of the principal grasses of the 

 tall grass prairie. It is also found in the 

 eastern states and the Rocky Mountains. It forms an important com- 

 ponent of wild prairie hay. Prairies, plains, stream banks, dry hills. 

 July — September. 



Figure 350 



182 



