408 



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



Figure 579. — Muhleribergia expansa. Panicle, X 1; 

 glumes and floret, X 10. (Tracy 3701, Miss.) 



1.5 m. tall, the numerous overlapping 

 lower sheaths keeled; ligule rather 

 thin, elongate, mostly hidden in the 

 folded base of the blade; blades elon- 

 gate, firm, flat or usually folded, about 

 3 mm- wide, scaberulous or glabrous; 

 panicle narrow, pale, somewhat loose, 

 erect, 20 to 40 cm. long, the branches 

 ascending or appressed; spikelets 2.5 

 to 3 mm. long; glumes acute to rather 

 obtuse, scabrous-puberulent; lemma a 

 little shorter to a little longer than the 

 glumes, 3-nerved, glabrous or ob- 

 scurely pubescent, awnless or rarely 

 with an awn as much as 3 mm. long. 

 % — Rocky slopes, Texas. 



66. Muhienbergia involuta Swal- 

 len. (Fig. 585.) Culms erect, densely 

 tufted, 60 to 135 cm. tall; sheaths 

 compressed-keeled, scabrous; ligule 

 about 10 mm. long; blades elon- 

 gate, involute, wiry, scabrous; panicle 

 erect, narrow, 30 to 40 cm. long, the 

 subcapillary branches ascending or 

 appressed, naked toward the base, the 



Figure 580. — Muhienbergia reverchoni. Panicle, X 1; glumes and floret, X 10. (Reverchon, Tex.) 



campes ligulata Scribn., not Muhien- 

 bergia ligidata Scribn. and Merr.) — 

 Canyons and rocky slopes, western 

 New Mexico, Arizona, southern Ne- 

 vada, and northern Mexico. 



65. Muhienbergia lindheimeri 

 Hitchc. (Fig. 584.) Culms erect, 1 to 



lower as much as 20 cm. long; spike- 

 lets 3 to 4.5 mm. long; glumes acute 

 or somewhat erose, scabrous, 2 to 2.5 

 mm. long; lemma densely pubescent 

 on the margin toward the very base, 

 the minutely toothed apex awned 

 from just below the teeth, the awn 



