AUROSTIDE.E. 253 



flowered. Spikelets sessile or subsessile; empty glumes lanceolate, 

 nearly equal, 1-nerved, about two-thirds as long as the floret, besides 

 the awns, which are 2-5 mm. long; floral glume lauce-ovate, mu- 

 cronate, thinly pubescent on the lower two-thirds, 3-nerved, 2.5-3.5 

 mm. long; palea obovate, lanceolate but little shorter than its 

 glume. 



Massachusetts, Cooley, Benl 51; Ontario, Fowler; Michigan, 

 r. S. Depf. AgnruJ 3U, from C*. F. AVheeler, ClarJc 1101, Coohij ; 

 Iowa, Hitclicock; Minnesota, Sandhery 42; Colorado, Cassidy ; 

 Montana, Williams; New Mexico, Jo7ies 4158; British Columbia, 

 Macoun. 



Found in wet ground from New England to Canada, Colorado, 

 Nevada, and Texas. Although the culms are, hard and the leaves 

 thin, the grass is much prized for hay for horses. See Vol. I. Fig. 

 81. 



Var. brevifolia Vasey, Coult. Bot. Gaz. 7:92 (1882). M. Cali- 

 f or 7iica Yasey, Bull. Torr. Club, 13:53 (1886). Blades 4-8 cm. 

 long, 4-6 mm. wide, floral glume usually bearing an awn 1-2 mm. 

 long. 



California, Parish Brothers 1028. 



Var. ramosa Vasey, Contrib. U. S. Nat. Herb. 3:68 (1892). 

 A taller much-branched plant, leaves longer, empty glumes about 

 as long as the floret, the awn shorter. 



Colorado, Tracy. 



Found from Illinois to Montana. 



29. M. microsperma (D C.) Trin. Unifl. 193 (1824). Tricho- 

 chloa microsperma D C. Cat. Ilort. Monsp. 151 (1813). Agrostis 

 microsperma Lag. Gen. et Sp. 2 (1816). Fodoscemum delile H. B. 

 K. Nov. Gen. 1:128 t. 681 (1815). Muhhnhergia debilis Trin. 

 Mem. Acad. St. Petersb. (VI.) 6:295 (1841). Muhlenberg ia pur - 

 piirea Nutt. Journ. Acad. Phila. (II.) 1: 186 (1848). 



Culms slender, ascending from a geniculate or stoloniferous 

 much-branched base. Sheaths mostly shorter than the iuternodes, 

 inflated or often crowded from them by the shortly calloused, bulb- 

 like branches, the sheaths of which firmly enclose the fertile floret; 

 ligule lascerate 1.5-2 mm. long; blades usually flat, often 2>iii"P^*^? 



