GRAMINEJS. 407 



simple. Spikelets compressed. Florets imbricated in 2 

 rows. Triandria. Digynia. 



C. unioloides P. de B. : panicle nodding, spreading ; spikelets ob- 

 long-lanceolate, compressed, 6 8-flowered ; florets acuminate, un- 

 armed ; sheaths bearded at the throat, the lower one hairy; root fi- 

 brous. Festuca unioloides Willd. 



HAB. Fertile soils. Penn. to Car. July. <j$ or y. Culm 18 

 inches high. Panicle small ; branches in pairs. 



35. DACTYLIS. Linn. 



Spikelets heaped into a unilateral head. Glume 2-valved, 

 many-flowered ; valves unequal, the larger one keeled. Pa- 

 lea 2, lanceolate, awnless ; lower one emarginate, mucronate ; 

 upper bifid, toothed. Panicle compound. 



Triandria. Digynia. 



D. glomerata Linn. : panicle secund, glomerate ; leaves carinate. 

 HAB. Fields and meadows. N. Y. to Car. June. Z Culm 



23 feet high. Panicle secund. Spikelets in thick ovate clus- 

 ters on the branches. Orchard- grass. 



36. TRICUSPIS. P. de Beauv. 



Spikelets terete, tumid, many-flowered. Glume 5 7-flow- 

 ered, carinate, shorter than the florets. Lower palea bifid- 

 toothed, between the teeth and on each side mucronate ; upper 

 one truncate, almost emarginate. Seed 2-horned. Panicle 

 compound. Triandria. Digynia. 



T. seslerioides Torr. : panicle expanding and flexuous ; spikelets aft 

 pedunculate, about 6-flowered, lanceolate ; lower palea ovate, 5-tooth- 

 ed. Poa seslerioides Mich. Muhl. JVindsoria poa/ormis Nutt. 



HAB. Sandy fields. N. S. S. to Car. Aug. 21. Culm 45 

 feet high, erect, smooth. Panicle very large, at length spread- 

 ing and pendulous. Red-top. 



37. KOELERIA. Pers. 



Spihekts compressed. Glume 2 3-flowered, beardless, 2- 

 valved ; valves shorter than the lowest floret. Palea 2, the 

 outer beardless or bearded under the point. Panicle spiked. 



Triandria. Digynia. 



1. K. pennsylvanica De Cand. : leaves flat and with the sheaths sofl- 

 ly pubescent ; panicle oblong, slender, rather loose ; glumes 2-flow- 

 ered, nearly equal ; the lower one oblong, obtuse, and slightly mu- 

 cronate ; upper palea scabrous. Aira mollis Muhl. 



HAB. Rocky woods. Penn. to Car. May, June. 21. Ctdm t 

 feet high, simple. Panicle long, with shining flowers. 



