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



Figure 842.— Distribution of 

 Sporobolus cryptandrus. 



or drooping, flexuous, loosely flowered. % — Mesas, western Texas 

 to southern Utah, southeastern California, and northern Mexico 

 (fig. 843). 



22. Sporobolus nealleyi Vasey. Nealley dropseed. 

 (Fig. 841, C.) Resembling dwarf forms of S. cryptan- 

 drus, but differing in the loose rhizomatous base; culms 

 slender, erect, 15 to 40 cm tall; blades slender, involute, 

 squarrose-spreading, mostly less than 5 cm long; panicle 

 delicate, open, 3 to 8 cm long some- 

 times enclosed in the sheaths, the 

 branches and branchlets spreading, 

 the spikelets less crowded than in 

 S. cryptandrus. % — Gypsum 

 sands, western Texas and New 

 Mexico. 



23. Sporobolus contractus 

 Hitchc. Spike dropseed. (Fig. 



841, D.) Differing from S. cryptandrus in the spikelike 

 panicle as much as 50 cm long, usually included at the 

 base, rarely entirely included in the sheath. % (S. 

 strictus Merr.) — Mesas, dry bluffs, and sandy fields, 

 Colorado to Nevada, south to western Texas, south- 

 eastern California, and Sonora; ad- 

 ventive in Maine (fig. 844). 



24. Sporobolus giganteus Nash. 

 Giant dropseed. (Fig. 845.) 

 Resembling S. cryptandrus and S. 

 contractus; culms 1 to 2 m tall, 

 erect, robust; blades as much as 1 

 cm wide; panicle usually thicker 

 than in S. contractus, less spikelike; 



spikelets 2.5 to 3 mm long. % — Mesas and sandhills, 

 western Texas to Arizona. 



25. Sporobolus buckleyi Vasey. (Fig. 846.) Peren- 

 nial the base strongly compressed; culms erect, slender, 

 40 to 80 cm tall; sheaths keeled, pubescent on the margin 

 and collar; blades flat, 4 to 7 mm 

 wide; panicle open, 10 to 30 cm 

 long, the slender branches widely 

 spreading, as much as 10 cm long, 

 solitary, rather distant, naked 

 below, with closely-flowered short- 

 appressed branchlets above; 

 spikelets about 1.5 mm long; 

 glumes narrow, the first a little shorter, the second a little 



Figure 8-13. — Distribution of 

 Sporobolus flexuosus. 



Figure 844— Distribution of 

 Sporobolus contractus. 



Figure 845.— 

 Sporobolus gi- 

 ganteus. Pan- 

 icle, X Vi, 

 glumes and 

 floret, X 10. 

 (Nealley, 

 Tex.) 



Figure 846.— Sporobolus buckleyi. Panicle, X M; glumes and floret, X 10. (Nealley, Tex.) 



