MANUAL OF THE GRASSES OF THE UNITED STATES 



777 



Figure 1179. — Sorghastrum elliottii, X 1. 

 1718, Ga.) 



(Harper 



Awn 20 to 35 mm. long, twice-geniculate, twisted below the second bend. 

 Spikelets chestnut-brown, the ultimate branchlets with a few long hairs at the tip only; 



panicle loose, not unilateral 2. S. elliottii. 



Spikelets yellowish brown, the upper portion of the ultimate branchlets conspicuously 



long-hairy toward the tip; panicle distinctly unilateral 3. S. secundum. 



1. Sorghastrum nutans (L.) Nash. 

 Indian grass. (Fig. 1178.) Culms 1 

 to 2.5 m. tall from short scaly rhi- 

 zomes; blades elongate, flat, mostly 

 5 to 10 mm. wide, tapering to a 

 narrow base, scabrous; panicle nar- 

 row, yellowish, rather dense, 15 to 

 30 cm. long, contracted and darker 

 at maturity; summit of branchlets, 

 rachis joints, and pedicels grayish- 

 hirsute; spikelets 6 to 8 mm. long, 

 lanceolate, hirsute, the awn 1 to 1.5 

 cm. long, once-geniculate. % — 

 Prairies, open woods, and dry slopes, 

 Quebec and Maine to Manitoba and 

 North Dakota, south to Florida and 

 Arizona; Mexico. 



2. Sorghastrum elliottii (Mohr) 

 Nash. (Fig. 1179.) Culms 1 to 1.5 

 m. tall, more slender than in S. 

 nutans, without rhizomes; the base 

 comparatively delicate, smooth or 

 nearly so; blades on the average 

 narrower; panicle loose, 15 to 30 

 cm. long, nodding at apex, the fili- 

 form branchlets and pedicels flexuous 

 but not recurved, with a few long 

 hairs at the tip; spikelets 6 to 7 mm. 

 long, chestnut brown at maturity, 

 with a short blunt bearded callus, 

 the first glume hirsute or glabrescent 

 on the back; awn 2.5 to 3.5 cm. long, 

 twice-geniculate. % — Open woods 

 dry hills, and sandy fields, eastern 

 Maryland to Tennessee, south to 

 Florida and Texas. 



3. Sorghastrum secundum (Ell.) 

 Nash. (lig. 1180.) Culms 1 to 2 m. 

 tall, without rhizomes, the base 

 robust and felty-pubescent; blades 

 mostly less than 5 mm. wide, flat 

 or subinvolute; panicle narrow, 20 

 to 40 cm. long, 1-sided, the branches 

 mostly in separated fascicles, the 

 capillary branchlets and pedicels 

 strongly curved or circinately re- 

 curved, stiffly long-pilose below the 

 tip; spikelets about 7 mm. long, _ _„ ■ , . , m v , m . 



, ^' r, ., .,, . , ° 7 Figure 1180. — Sorghastrum secundum, X 1. Ulooa, 



brownish, pilose, with an acute dense- Fia.) 



ly bearded callus 1 to 1.5 mm. long. 

 91 — Pine barrens, South Carolina 

 to Florida and Texas. 



