MANUAL OF THE GRASSES OF THE UNITED STATES 753 



2. Sorghastrum elliottii (Mohr) Nash. (Fig. 1672.) 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. 



01 — Open woods, dry hills, and sandy fields, eastern Maryland to 

 Tennessee, south to Florida and Texas (fig. 1673). 



3. Sorghastrum secundum (Ell.) Nash. (Fig. 1674.) Culms 1 to 



2 m tall, without rhizomes, the base robust and f elty-pubescent ; 

 blades mostly less than 5 mm wide, flat 



or subinvolute; panicle narrow, 20 to 40 



Figure 1673. — Distribution of 

 Sorghastrum elliottii. 



Figure 1674.- 



-Sorghastrum secundum, 

 (Hood, Fla.) 



Figure 1675.— Distribution of 

 Sorghastrum secundum. 



cm long, 1 -sided, the branches mostly in 

 separated fascicles, the capillary branch- 

 lets and pedicels strongly curved or cir- 

 cinately recurved, stiffly long-pilose below the tip; spikelets about 

 7 mm long, brownish, pilose, with an acute densely bearded callus 1 to 

 1.5 mm long. 01 — Pine barrens, South Carolina to Florida and 

 Texas (fig. 1675). 



149. RHAPHIS Lour. 



Spikelets in threes, one sessile and perfect, the other two pedicellate 

 and sterile, or sometimes a pair below, one fertile and one sterile ; 

 fertile spikelet terete, the glumes coriaceous; sterile and fertile 

 lemmas thin and hyaline, the latter awned. Perennial grasses, or, 

 our species, annual, with open panicles, the three spikelets (reduced 

 raceme) borne at the ends of long, slender, naked branches. Type 

 species, Rhaphis trivialis Lour. (R. aciculatus Honda, Andropogon 

 aciculatus Retz.). Name from Greek rhaphis, needle; alluding to the 

 slender pointed callus. 



1. Rhaphis pauciflorus (Chapm.) Nash. (Fig. 1676.) Annual; 

 culms 60 to 120 cm tall, erect or somewhat decumbent at base; 

 blades flat, mostly 4 to 8 mm wide; panicle loose, the axis 5 to 10 

 cm long, the branches few, very slender, 5 to 8 cm long; sessile spike- 



