80 



Fig. 58. Agrostis alba Linn. RED-TOP.— a, Empty glumes; b, floret inclosing 

 stamens. Other species of Agrostis are illustrated by figs. 135 to 140, in Bui. 7, 

 and 478 to 484, in Bui. 17. 



58. AGROSTIS Linn. Sp.P1.6. 1753. Spikelets 1-flowered; rachilla articu- 

 lated above the empty glumes, not produced beyond the flower. Empty glumes 

 2, equal or nearly so, acute, longer than the floret; flowering glume rather 

 broad, less firm in texture than the outer glumes, usually obtuse, awnless, or 

 with a slender dorsal awn. Palea hyaline, much shorter than the floral glume, 

 or Avholly absent. Stamens 3. Grain inclosed by the floral glume, but free 

 from it. Annual or usually perennial grasses, with small spikelets in open, 

 usually diffuse panicles. 



Species about 100, distributed over the entire world, especially in the north 

 temperate zone. In the United States the species are most numerous in the 

 far Northwest. 



