MANUAL OF THE GRASSES OF THE UNITED STATES 373 



below the nodes, simple or sparingly branching, the branches erect; 



sheaths smooth, keeled; blades flat, mostly appressed, scabrous, 5 to 



10 cm long, 2 to 5 mm wide; panicle narrow, compact or lobed, 



bristly, 3 to 10 cm long; spikelets 4 to 6 mm long, 



the narrow subequal glumes stiffly awn-tipped ; 



lemma acuminate, about 3 mm long, pilose on 



lower part. % — Moist meadows and low 



ground, Newfoundland to British Columbia, 



south to Maryland, Kentucky, Oklahoma, and 



Arizona (fig. 769). 



26. Muhlenbergia mexicana (L.) Trim Wire- 

 stem muhly. (Fig. 770.) Perennial, with 

 creeping scaly rhizomes; culms decumbent and 



Figure 763. — Distribution of 

 Muhlcnbergia sobolifera. 



rooting at base, 

 freely branching from all the 

 nodes, the branches ascend- 

 ing, the plants becoming top- 

 heavy and bushy, the culms 

 glabrous below the nodes; 

 blades flat, scabrous, usually 

 less than 10 cm long, but 

 sometimes as much as 15 

 cm, 3 to 7 mm wide; panicles 

 numerous, short-exserted or 

 partly included, terminal and 

 axillary, the larger as much 

 as 10 cm long, the axillary 

 shorter, narrow, the branches 

 ascending, mostly densely 

 flowered from the base; 

 glumes 2 to 3 mm long or 

 slightly longer, narrow, taper- 

 ing into an awn-tip; lemma 

 about equaling the glumes, 

 acuminate, short-pilose at 

 base. 9[ — Thickets, low 

 ground, and waste places, 

 New Brunswick to North 

 Dakota, south to the moun- 

 tains of Georgia and Texas 

 (fig. 771). This species does 

 not grow in Mexico. It was originally described from a garden speci- 

 men cultivated by Linnaeus in his Upsala 

 Garden and erroneously credited to Mexico. 



MUHLENBERGIA MEXICANA Var. COMMUTATA 



Scribn. Lemmas awned, the awns 4 to 10 mm 

 long. 21 — Quebec and Maine to South 

 Dakota, south to Virginia and Missouri; less 

 common than the species. May be distin- 

 guished from M. foliosa var. setiglumis, winch 

 it sometimes resembles, by the culms smooth 

 below the nodes and the included or scarcely exserted panicles. 



27. Muhlenbergia glabriflora Scribn. (Fig. 772.) In habit re- 

 sembling M. mexicana, freely branching; culms scaberulous below the 



Figuke 764.— Muhlenbergia tenui flora. Plant, X 1; glumes 

 and floret, X 10. (Mosley, Ohio.) 



Figure 765.— Distribution of 

 Muhlenbergia tenuiflora. 



