MANUAL OF THE GRASSES OF THE UNITED STATES 



707 



shorter than the spikelet, the inner densely silky-plumose below, as 

 much as 1 cm long; spikelets solitary, 3.2 to 4 mm long. % — Open 

 slopes and savannas, southern Florida; tropical America. 



3. Pennisetum nervosum (Nees) Trim (Fig. 1584.) Perennial; 

 culms robust, branching, as much as 3 m tall; blades elongate, 5 to 

 10 mm wide, scabrous; panicle dense, somewhat flexuous, 10 to 20 cm 

 long; fascicles spreading to reflexed; bristles scabrous, the outer about 

 as long as the spikelet, the inner about 10 mm long; spikelet solitary, 

 5 to 6 mm long. % —Moist open or brushy places, Brownsville, 



Figure 1583.— Pennisetum setosum, X V2. 

 (Amer. Gr. Nat. Herb. 611, Trinidad.) 



Figure 1584. — Pennisetum nervosum, 

 X V 2 . (Ferris and Duncan 3198, 

 Tex.) 



Tex., a single locality along the Rio Grande, apparently introduced; 

 Ecuador to Brazil and Argentina. 



4. Pennisetum villosum R. Br. Feathertop. (Fig. 1585.) Per- 

 ennial; culms tufted, 30 to 60 cm tall, pubescent below the panicle; 

 blades 3 to 5 mm wide; panicle tawny, ovoid or oblong, 3 to 10 cm 

 long, 1 to 5 cm wide including bristles, dense, feathery; spikelets 1 to 4 

 in a fascicle; fascicles short-peduncled, a tuft of white hairs at base of 

 peduncle; bristles numerous, spreading, the inner very plumose, the 

 longer 4 to 5 cm long. 91 (P. longistylum of florists, not Hochst.) — 

 Cultivated for ornament, sparingly escaped in dry ground, Michigan, 

 Texas, and California; introduced from Africa. 



5. Pennisetum ruppelii Steud. Fountain grass. (Fig. 1586.) 

 Perennial, culms tufted, simple, about 1 m tall; blades narrow, elon- 



