CLASS III. ORDER III. 33 



a third of an inch long. Dry woody hills near the Andover 

 turnpike, Medford. — June, July. — Perennial. 



38. AIRA. 

 AiRA FLEXuosA. L. VVood Hair grass. 



Panicle spreading, trichotomous ; peduncles flex- 

 uous, awns geniculate; leaves setaceous, culm nearly 

 naked. 



A tall thin grass found in old woods, one or two feet high. 

 Glumes membranaceous, purplish. Corolla with a bent awn 

 near the base. — Sides of Wachusett hill. — June. 

 AiRA TRUNCATA. 3IuhL Truiicate Hair grass. 



Panicle oblong, racemose: calyx unequal, three 

 flowered, one abortive ; lower glume obtuse, corolla 

 glabrous. 

 Syn. KoELERiA truncata. Torrey. 



Woods, Watertown. — June. 



39. UNIOLA. 

 Uniola spicata. L. SpiJce grass. 



Somewhat spiked ; leaves involute, rigid. L. 



A common grass of the salt marshes. Stem a foot high, 

 round, smooth. Leaves of the stem numerous, short, smooth, 

 increasing in frequency upward, the upper ones hardly an inch 

 apart, rolled up so as to acquire a setaceous form, commonly 

 investing, and often overtopping the spike. Spike irregular, 

 about an inch long, consisting of ten or a dozen small, com- 

 pressed, crowded spikelets. Glumes flattened, sharp on the 

 back. — July. — Perennial. 



40. DACTYLIS. 



Dacttlis glomerata, L. Orchard grass. 



Panicle crowded, leaning one way. Srn. 



Pioot perennial. Culms round, rough toward the top. Leaves 

 very rough. Stipules cloven or torn. Panicle of flowers con- 

 sisting of close bunches on rough and rigid peduncles j leaning 



