MANUAL OF THE GRASSES OF THE UNITED STATES 



427 



part of the main branches; spikelets 

 from pale to leaden, 2 to 2.5 mm. 

 long; first glume one-third to half 

 as long, the second about as long- 

 as the acute lemma and palea. % 

 — Sandy open ground, Maine and 

 Ontario to Alberta and Washington, 

 south to North Carolina, Indiana, 

 Louisiana, southern California, and 

 northern Mexico. 



22. Sporobolus flexuosus (Thurb.) 

 Rydb. Mesa dropseed. (Fig. 611.) 

 Resembling S. cryptandrus, differing 

 in the more open often elongate pan- 

 icles, the slender branches and branch- 

 lets spreading or drooping, flexuous, 

 loosely flowered. % — Mesas, 

 western Texas to southern Utah, Ne- 

 vada, southern California, and north- 

 ern Mexico. 



23. Sporobolus nealleyi Vasey. 

 Nealley dropseed. (Fig. 612.) Re- 

 sembling dwarf forms of S. cryptan- 

 drus, but differing in the loose rhi- 

 zomatous base; culms slender, erect, 

 15 to 40 cm. tall; blades slender, in- 

 volute, squarrose-spreading, mostly 

 less than 5 cm. long; panicle delicate, 

 open, 3 to 8 cm. long, sometimes en- 

 closed in the sheaths, the branches 



Figure 612. — Sporobolus nealleyi. Panicle, 

 glumes and floret, X 10. (Nealley, Tex. 



X 



Figure 611. — Sporobolus flexuosus. Plant, X X A\ 

 glumes and floret, X 10. (Vasey, N. Mex.) 



Figure 613. — Sporobolus con- 

 tractus. Panicle, X X A ', glumes 

 and floret, X 10. (Pringle, 

 Ariz.) 



and branchlets spreading, the spike- 

 lets less crowded than in S. cryptan- 

 drus. 91 — Gypsum sands, western 

 Texas, Nevada, New Mexico and 

 Arizona. 



24. Sporobolus contractus Hitchc. 

 Spike dropseed. (Fig. 613.) Differing 

 from S. cryptandrus in the spikelike 

 panicle as much as 50 cm. long, usually 



