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



pediceled; glumes acute, the first 2 to 3 mm, the second 4 to 6 mm 

 long; lemma and palea acute, about equal. 21 Grassy plains and 

 hills, Arizona. The second glume and lemma may have wrinkles 

 toward the summit that look like nerves. 



12. Sporobolus heterolepis A. Gray. 

 PRAIRIE DROPSEED. (Fig. 830.) Per- 

 ennial, in dense tufts; culms erect, 

 slender, 30 to 70 cm tall; sheaths 

 somewhat pilose at the throat, the 

 lower sometimes sparsely pilose on the 

 back; blades elongate, flat, becoming 

 involute at the slender attenuate tip, 

 2 mm or less wide; panicle, 5 to 20 

 cm long, the branches ascending or 

 spreading, 3 to 6 cm long, naked be- 

 low, few-flowered above; spikelets 

 grayish; glumes acuminate, the first 

 2 to 4 mm long, the second 4 to 6 mm 

 long; lemma shorter than the second 

 glume, palea slightly longer than the 

 lemma; caryopsis globose, nutlike, 

 nearly 2 mm thick, finally splitting 



FIGURE 828. Distribution of 

 Sporoboliis clandestinus. 



the palea. 01 Prairies, Quebec to 

 Saskatchewan and Wyoming, south 

 to Connecticut, Illinois, Arkansas, and 

 eastern Texas (fig. 831). 



13. Sporobolus curtissii (Vasey) 

 Small. (Fig. 832.) Perennial, in dense 

 tufts; culms slender, 30 to 70 cm tall; 

 basal sheaths pilose at the throat; 

 blades flat or folded, flexuous, about 

 1 mm wide, pilose on the upper sur- 

 face near the base ; panicle pyramidal, 

 open, 7 to 20 cm long, the branches 

 solitary or in twos, ascending; spike- 

 lets appressed along the main branch- 

 es, bronze or purplish, about 4.5 mm 

 long; glumes about equal, acuminate, 

 as long as or longer than the lemma 

 and palea. 91 Dry pine barrens, 

 North Carolina, Georgia, and Florida. 



14. Sporobolus teretifolius Harper. (Fig. 833.) Perennial, in 

 tufts; culms erect, wiry, 60 to 80 cm tall, sheaths pilose at the throat; 

 blades elongate, slender, terete, wiry, flexuous, pilose on the upper 

 surface at base; panicle pyramidal, open, 15 to 20 cm long, the capil- 



FIGUEE 829.Sporobotus interruptus. Plant, X 

 1; glumes and floret, X 10. (Rusby, Ariz.) 



