8 SPRING FLORA OF MANHATTAN. 



F. obtusata, (Michx ) Gray. An upright smooth grass I to $ m. high, 

 with contracted panicle, Prairie, common. 



KXELERIA, Pers. 



Spikelets 2-4-flowered; empty glumes somewhat unequal, about the 

 length of the spikelet, acutsh. 



K cristata, (L.) Pers. Resembling the previous species but stem 

 pubescent above and panicle rather more contracted Prairie, common. 



DACTYLIS. L 



Spikelets 3-4 flowered, crowded in 1-sided clusters; empty glumes 

 short awned, flowering glume 5 nerved. 



D ylomerata, L. An upright, tufted grass A m. high or more, with 

 rather broad leaves Escaped from cultivation 



POA, L 



Spikelets ovate, compressed, 2-several flowered, in open panicles. 

 Empty glumes shorter than flowers Flowering glume keeled, 5 nerved, 

 with a scarious margin. Awns none 



P. compressa. L. Panicle short and narrow. Stem flattened, wiry, 

 2-4 dm. high. Leaves short and erect. Perennial by running rootstocks. 

 Sterile ground. 



P. pratensis, L. Panicle pyramidal, short. Stem cylindrical, 

 upright, 2-6 dm high Escaped from cultivation, common. 



P. sylvestris, Gray. Panicle loose and open, pedicels slender. Stem 

 (2-6 dm.) and leaves soft and weak. Upland woods. 



FESTUCA, L. 



Spikelets 3-several flowered. Panicle open or contracted. Flower- 

 ing glume coriaceous, convex on back. 3-5 nerved, acute or awned from 

 tip. 



F. oetoflora, Walt. Panicle often contracted into a simple raceme. 

 Flowering glume short awned. Leayes few and short, convolute. Stem 

 erect, 1-4 dm. high. Sterile soil, common 



F. elatior, var. pratensis, (Huds.) Hack. Panicle simple. Glumes 

 awnless. Leaves flat. Stem tall; i m or more. Escaped from cultiva- 

 tion. 



BROMUS, L 



Spikelets several flowered, panicled. Empty glumes unequal, nerved. 

 Flowering glume convex on back, or keeled above, nerved, awned below 

 the 2-cleft apex. 



B seealimis, L. Panicle often simple, pedicels rough, slender. 

 Lower empty glume acute, narrow, 3-nerved; upper broader and longer, 

 7-nerved Flowering glume about 7-nerved; awn shorter than glume. 

 A weed in fields. 



HORDEUM, L 



Spikelets 1-flowered, sessile on a zig zag rhachis, 3 at each joint, the 

 2 lateral more or less imperfect, the 6 empty glumes bristle form, stand- 

 ing side by side in front of the spikelets. Flowering glume long awned 

 from the apex. 



H. jubatum, L. Awn capillary, spreading, 2-5 cm long. Stems 

 about A m. high. Waste places, infrequent. 



