GENERA OF GRASSES OF THE UNITED STATES. 159 



Perennial grasses, with usually convolute blades and narrow pan- 

 icles. Species about 100, in the temperate regions of the world, 

 especially on plains and steppes; 30 species in the United States, 

 mostly in the western part. 



Type species : Stipa pennata L. 



Stipa L., Sp. 1M. 78, 1753 ; Gen. PI., ed. 5, 34. 1754. Limireus describes three 

 species, . pennata, 8. juncea, and S. avenacca. The first two are from central 

 and southern Europe, the third from Virginia. The first species is selected as 

 the type. 



