378 



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



overmature specimens. O — Rocky 

 canyons and slopes, western Texas to 

 Arizona, northern Mexico, and Baja 

 ( alifornia; rare or overlooked. 



Figure 525. — Muhlenbergia eludens. Plant, X 1; 

 glumes and floret, X 8. (Pringle 399, Mex.) 



6. Muhlenbergia eludens C. G. 



Reeder. (Fig. 525.) Annual, branching 

 at base, culms slender, erect, 15 to 35 

 cm. tall, the culms strongly unequal; 

 foliage scant, scabrous; ligule 2 to 2.5 

 mm. long; blades mostly 4 to 7 cm. 

 long to 1.5 mm. wide, involute up- 

 ward; panicle half to three-fourths 

 the length of the plant, the slender 

 branches relatively stiffly spreading; 

 spikelets 2.2 to 2.5 mm. long, on short 

 pedicels, mostly closely appressed to 

 the branches; glumes about 1 to 

 1.5 mm. long, hirsute; lemma 2.3 mm. 

 long, silky on the midnerve and mar- 

 gins, slightly notched and with an 

 awn 2 to 2.5 mm. long. O (In- 

 cluded in M . texana in Manual, ed. 

 1.) — Rock}' woods and wet ledges and 

 gravel bars, to 2,400 m. altitude, New 



Mexico, Arizona, and northern Mex- 

 ico. 



7. Muhlenbergia microsperma 



(DC.) Kunth. LlTTLESEED MUHLY. 



(Fig. 526.) Annual; culms densely 

 tufted, branching and spreading at 

 base, often purple, 10 to 30 cm. tall; 

 blades mostly less than 3 cm. long, 1 

 to 2 mm. wide, scabrous; panicles 

 narrow, 5 to 15 cm. long, the branches 

 rather distant, ascending; spikelets on 

 short thick pedicels; glumes broad, 

 obtuse, subequal, less than 1 mm. 

 long; lemma narrow, 2 to 4 mm. long, 

 scabrous, the slender awn 1 to 3 cm. 

 long. O — Open dry ground, 

 Nevada, Arizona, and southern Cali- 

 fornia to Peru. Cleistogamous spike- 

 lets are developed at the base of lower 

 sheaths, solitary or few in a fascicle in 

 each axil, each spikelet included in an 

 indurate thickened, tightly rolled nar- 

 rowly conical reduced sheath, which 

 readify disarticulates from the plant 

 at maturity. The glumes are wanting 

 and awn of lemma reduced, but the 

 grain is larger than that of the spike- 

 lets in the terminal inflorescence, 

 being about the same length (2 mm.) 

 but much thicker. 



Figure 526. — Muhlenbergia microsperma. Plant, X 1; 

 glumes and floret, X 10. (Mearns 2780, Ariz.) 



