these racemes attached along an axis, the axis being elongate); zone of abscission 

 just below each lemma, the marginal basal portion of the lemma pubescent or 

 nearly glabrous. 



A genus of about 27 species in the warmer parts of the world. 



1. Lemma 1-1.5 mm. long (2) 



1. Lemma at least 1.8 mm. long (3) 



2(1). Panicles more than 10 times as long as broad; racemes stiffly ascending 

 or appressed 4. L. Nealleyi. 



2. Panicles much less than 10 times as long as broad 5. L. filiformis. 



3(1). Recemes usually more than 40 per panicle; spikelets 3.5-4.5 mm. long; 

 lemmas about 2 mm. long, acute 3. L. panicoides. 



3. Racemes usually fewer than 40 per panicle; spikelets 4-10 mm. long; lemmas 



1.8-4 mm. long (4) 



4(3). Lemmas lance-elliptic, acute and acuminate, 2.5-4 mm. long 



, 1. L. fascicularis. 



4. Lemmas obovate, blunt, 1.8-3 mm. long 2. L. uninervia. 



1. Leptochloa fascicularis (Lam.) Gray. Bearded sprangletop. Fig. 119. 

 Tufted annual; culms 2-9 dm. long, 2-3 mm. thick, erect or geniculately 



ascending, sparingly branched, leafy, soft; ligule a hyaline scale 2.5-6 mm. long, 

 usually lacerate into several strap-shaped parts, the lateral portions resembling 

 auricles on the sheaths; blades 5-35 cm. long. 2-10 mm. broad, flat or soon 

 involute; panicles 15-30 cm. long, 2-5 cm. broad, usually partly included in the 

 sheath; racemes 14 to 35, widely spaced on the panicle axis but appressed or 

 ascending and overlapping, 3-1 1 cm. long, 3-5 mm. thick; spikelets scarcely 

 laterally compressed, overlapping, 5-10 mm. long, 6- to 12-flowered; glumes 

 1.5-3.5 mm. long, acute; lemma lance-elliptic, 2.5-4 mm. long, acute or acumi- 

 nate to mucronate or short-awned, pubescent near the margin in the lower half, 

 the hairs conspicuous from the side of the spikelet under a lens. 



Muddy areas, sometimes alkaline or subsaline mud, brackish marshes, about 

 playa lakes, in seepage areas, and in shallow water of ponds and streams, in 

 Okla. (Logan and Pawnee cos.), in the Tex. Plains Country, Trans-Pecos, Rio 

 Grande Plains, and n.-cen. and s.e. Tex., scattered but locally abundant, N. M. 

 (Lea, Socorro, Dona Ana, Chaves and Eddy cos.) and Ariz. (Coconino, Navajo, 

 Graham, Gila, Pinal, Cochise and Pima cos.) summer-fall; widespread in the 

 warmer parts of the New World, n. to N. E., N. D. and Wash. (See remark under 

 L. uninervia.) 



2. Leptochloa uninervia (Presl) Hitchc. & Chase. Fig. 120. 



Much like L. fascicularis, identical in habit; racemes 20 to 40, 2-8 cm. long; 

 spikelets 4-9 mm. long; glumes and lemmas much less acute, the latter 1.8-3 mm. 

 long, obovate and obtuse or muticous, sometimes mucronate, the pubescence in- 

 conspicuous or hidden when spikelet is viewed from the side. 



Mud, sometimes alkaline or subsaline mud, in ditches, along and in sloughs 

 and river sand bars, in Okla. (Love Co.) and in the Tex. Edwards Plateau, Rio 

 Grande Plains, s.e. and Trans-Pecos Tex., to be expected in n.-cen. Tex. and the 

 Plains Country, scattered, spring-summer, rarely into fall; widespread but scat- 

 tered in the warmer parts of the New World n. to N. E., Okla., Colo., Ut. and 

 Ore. Perhaps only a form of L. fascicularis. 



3. Leptochloa panicoides (Presl) Hitchc. 



Tufted annual; culms 5-10 dm. long. 2-6 mm. thick, erect, sparingly or not 

 branched, leafy, soft; ligule a hyaline usually lacerate scale 2-4 mm. long; blades 

 2-5 dm. long, 3-10 mm. broad, folded or drying involute: sheaths sharply keeled; 



253 



