420 



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



S&1 



'i 





wife 



mm 



1 



Figure 598. — Sporobolus indicus. Panicle, X 1; spike- 

 let and floret, X 10. (Leon 867, Cuba.) 



on the innovations longer; panicle 

 pale, contracted or spikelike, 2 to 8 



■ If 



ml 



Figure 599. — Sporobolus virginicus. Plant, X 1; 

 glumes and floret, X 10. (Nash 2467, Fla.) 



cm. long, 5 to 10 mm. thick; spike- 

 lets 2 to 2.5 mm. long; glumes and 

 lemma about equal. % — Sandj' 

 or muddy seashores and saline marsh- 

 es, forming extensive colonies, with 

 relatively few flowering culms, south- 

 eastern Virginia (Gronovius, Fl. Virg.) 

 to Florida and Texas, south through 

 the West Indies to Brazil. Readily 

 grazed where available. A robust 

 form (called S. littoralis (Lam.) 

 Kunth), with culms as much as 1 

 m. tall and panicles as much as 15 

 cm. long, is found in the West Indies 

 and extends into Florida. Complete 

 intergradations are found, and the 

 type specimen is not the robust form. 



11. Sporobolus interruptus Vasey. 

 Black dropseed. (Fig. 600.) Peren- 

 nial, densely tufted; culms erect, 30 

 to 60 cm. tall, the leaves crowded at 

 base, about 2 on the culm; sheaths 

 more or less pilose; blades flat or 

 folded, sparsely pilose to glabrous, 

 1 to 2 mm. wide; panicle 10 to 20 cm. 

 long, brownish-leaden, the branches 

 distant, finally spreading, naked 

 at base; spikelets about 6 mm. long, 

 short-pediceled; glumes acute, the 

 first 2 to 3 mm., the second 4 to 6 

 mm. long; lemma and palea acute, 

 about equal. % — 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) A. Gray. Prairie dropseed. 

 (Fig. 601.) Perennial, 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 below, 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 the palea. 01 — 



