408 MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



longer, than the acute lemma; palea about as long as the lemma, 

 splitting as the grain (1 mm long) ripens. % — Texas and eastern 

 Mexico. 



26. Sporobolus airoides (Torr.) Torr. Alkali sacaton. (Fig. 

 847.) Perennial, in large tough bunches ; culms erect to spreading, 50 

 to 100 cm tall; sheaths pilose at the throat; ligule pilose; blades 

 elongate, flat, soon becoming involute, usually less than 4 mm wide, 

 often flexuous; panicle nearly half the entire height of the plant, at 

 maturity half to two-thirds as wide as long, the 

 stiff slender branches and branchlets finally 

 widely spreading, naked at base, the spikelets 

 aggregate along the upper half to two- thirds; 

 spikelets 2 to 2.5 mm long, the first glume about 

 half as long, commonly falling toward matu- 

 rity; second glume, lemma, and palea about 

 equal, the palea splitting as the grain ripens. 

 01 — Meadows and valleys, especially in mod- 

 erately alkaline soil, South Dakota to eastern Washington, south to 

 Texas and southern California (fig. 848). Mature spikelets with the 

 first glume fallen and the palea split to the base are puzzling to the 

 beginner. Less mature complete spikelets will usually be found at the 

 base of the panicle. A good forage grass in alkaline regions ; of ten 



Figure 848.— Distribution of 

 Sporobolus airoides. 



called bunchgrass. 



27. Sporobolus wrightii Munro. 



Sacaton. (Fig. 849.) Peren- 



nial, in large dense tufts; culms robust, erect, firm and hard, 1 to 2 m 

 tall; sheaths sparsely pilose at the throat; ligule pilose; blades elon- 

 gate, flat, involute in drying, 3 to 6 

 mm wide ; panicle pale, narrow, open, 

 mostly 30 to 60 cm long, the branches 

 crowded, straight, stiffly ascending, 

 the branchlets appressed, closely flow- 

 ered from the base or nearly so; spike- 

 lets 2 to 2.5 mm long, the first glume 

 about one- third as long, the second 

 two-thirds to three-fourths as long, 

 acute; lemma and palea about 

 equal. % — Mesas and valleys, 

 southern and western Texas to south- 

 ern California and central Mexico 

 (fig. 850). Useful for grazing when 

 young ; also furnishes hay and makes 

 good winter range. 



28. Sporobolus texanus Vasey. 

 (Fig. 851.) Perennial, in close hemi- 

 spherical tuf ts ; culms erect to spread- ^SSiS?^ 7jX&JSS&!&z 

 mg, slender, wiry , 30 to 50 cm tall ; 



sheaths pilose at the throat, the lower often papillose-pilose on the 

 surface; blades flat, involute in drying, mostly less than 10 cm 

 long, 1 to 4 mm wide; panicle open, rather diffuse, breaking away at 

 maturity, 15 to 30 cm long, about as wide, the capillary scabrous 

 branches, branchlets, and long pedicels stiffly spreading; spikelets 

 about 2.5 mm long, the first glume acute, one- third to half as long, the 

 second acuminate, slightly exceeding the acute lemma and palea, the 

 palea early splitting. % — Mesas, valleys, and salt marshes, 

 Kansas to Colorado, Texas, and New Mexico (fig. 852), 



