492 



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



Figure 721. — Leptochloa dubia. Panicle, X 1; two views of floret, X 

 10. (Small, Carter, and Small 3572, Fla.) 



gentina. Racemes of cleistogamous 

 spikelets are often found in the 

 sheaths. 



2. Leptochloa chloridiformis 



(Hack.) Parodi. (Fig. 722.) Robust 

 tufted perennial, somewhat glaucous; 

 culms erect, 80 to 150 cm. tall; sheaths 

 scaberulous; ligule a dense line of 

 white hairs, 1 to 2 mm. long; blades 

 erect, elongate, flat, rather firm, 3 

 to 4 mm. wide, villous on the upper 

 surface near the base, the margins 

 scabrous, long-attenuate ; panicle long- 

 exserted; spikes numerous (usually 

 10 to 15), pale or stramineous, erect 

 at base, flabellate or outcurved above, 

 10 to 15 cm. long, aggregate in 2 or 



3 whorls on an axis 3 to 4 cm. long; 

 spikelets closely imbricate on a rachis 

 0.5 mm. wide, 4-flowered, about 



4 mm. long; glumes acute, the first 

 1.5 mm. long, the second 2.5 to 3 

 mm. long; lemmas keeled, pilose on 

 the margins nearly to apex, the mid- 

 nerve extending beyond the obtuse 

 tip as a minute mucro, the first and 

 second florets about 3 mm. long, 

 the other shorter, not extending 

 much beyond the first two. % — 

 Dry open ground, Cameron County, 

 Tex.; Paraguay and Argentina. 



3. Leptochloa virgata (L.) Beauv. 

 (Fig. 723.) Perennial; culms wiry, 

 erect, 50 to 100 cm. tall; blades flat; 

 racemes several to many, slender, 

 laxly ascending, 5 to 10 cm. long, the 



lower distant, the others often aggre- 

 gate; spikelets nearly sessile, mostly 

 3- to 5-flowered; lemmas 1.5 to 2 mm. 

 long, awnless or the lower with a 

 short awn. % — Open ground and 

 grassy slopes, southern Florida and 

 southern Texas; tropical America. 



4. Leptochloa domingensis (J acq.) 

 Trin. (Fig. 724.) Resembling L. vir- 

 gata; sheaths and blades sparsely 

 pilose; panicle more elongate, the 

 racemes shorter and more numerous; 

 lemmas appressed-pubescent on the 

 internerves, awned, the awn of the 

 lower florets 1 to 3 mm. long. % 

 — Open ground and grassy slopes, 

 southern Florida; Texas; tropical 

 America. 



5. Leptochloa filifdrmis (Lam.) 

 Beauv. Red sprangletop. (Fig. 725.) 

 Annual; the foliage and panicles often 

 reddish or purple; culms erect or 

 branching and geniculate below, 40 

 to 70 cm. tall, or often dwarf; sheaths 

 papillose-pilose, sometimes sparsely 

 so; blades flat, thin, as much as 1 cm. 

 wide; panicle somewhat viscid, of 

 numerous approximate slender ra- 

 cemes 5 to 15 cm. long, on an axis 

 mostly about half the entire length of 

 the culm; spikelets 3- to 4-flowered, 

 1 to 2 mm. long, rather distant on the 

 rachis ; glumes acuminate, longer than 

 the first floret, often as long as the 

 spikelet; lemmas awnless, pubescent 

 on the nerves, 1.5 mm. long. O 



