Muhlenbergia Agrostideae 131 



or moist soil along roadsides and railroads and in fallow fields, pastures, 

 and waste places. 



Nat. of Eurasia; throughout the U. S. 



75-215. MUHLENBERGIA Schreb. Muhly 



[Note: In this genus the measurements of the spikelets, glumes, and lemmas do not 

 include the awns, unless so stated. In observing nodes and internodes, both the lower 

 and the upper ones of the plant should be examined.] 



Panicles diffuse, more than 2.5 cm wide, usually 10-20 cm wide 1. M. capillaris. 



Panicles not diffuse, less than 2.5 cm wide. 



First glume obsolete ; second glume not over 0.6 mm long, very obtuse 



2. M. Schreberi. 



First glume not obsolete; second glume more than 0.6 mm long, not obtuse. 



Spikelets 1.5-2.2 mm long; glumes shorter than the lemmas (if as long, see opposing 

 lead). 



Lemmas acute to acuminate, not awned 3. M. sobolifera. 



Lemmas awned 3a. M. sobolifera f . setigera. 



Spikelets more than 2.2 mm long. 



Lemmas not pilose at the base (on the callus). 



Culms without creeping rootstocks; anthers about 1-1.5 mm long 



4. M. cuspidata. 



Culms with creeping scaly rootstocks; anthers about 0.5 mm long 



5. M. glabriflora. 



Lemmas short-pilose at the base (on the callus). 

 Nodes and infranodes glabrous. 



Panicles included at the base, rarely short-exserted ; anthers about 0.5 mm 

 long. 



Lemmas without awns, or some with short awns up to 2 mm long 



6. M. mexicana. 



Lemmas awned ; awns usually 5-10 mm long 



6a. M . mexicana f . commutata. 



Panicles usually very long-exserted ; anthers about 0.8 mm long 



7. M. brachyphylla. 



Nodes and infranodes not glabrous. 



Nodes and infranodes puberulent; anthers about 0.8 mm long. 



Glumes longer than the lemma ; panicles more than 5 mm wide 



8. M. racemosa. 



Glumes usually two thirds to three fourths as long as the lemma; panicles 



generally less than 5 mm wide 9. M. tenuiflora. 



Nodes glabrous; infranodes puberulent, rarely nearly all glabrous, but not 

 polished below the node; anthers about 0.5 mm long. 

 Culms usually puberulent below the panicles; spikelets crowded on the 

 branches, glumes about as long as the lemmas. 



Lemmas awnless 10. M. foliosa. 



Lemmas awned, awns 4-10 mm long 10a. M. foliosa f. ambigua. 



Culms generally glabrous below the panicles; spikelets not at all crowded 

 on the branches; glumes about two thirds as long as the lemmas. 



Lemmas awned 11. M. sylvatica. 



Lemmas awnless 11a. M. sylvatica f. attenuata. 



1. Muhlenbergia capillaris (Lam.) Trin. Map 217. My only specimen 

 was collected October 7, 1921, about 3 miles east of Elizabeth, on an open 

 wooded, rocky hillside, bordering the roadside of the Elizabeth Road to 

 Stewart's Landing, Harrison County. It was still persisting here in 1938. 



Mass., Ind., and Kans., southw. to Fla. and Tex. ; W. I. and e. Mex. 



