11 



This is, next to the Festucea', the largest tribe in the 

 order, numbering seven hundred species arranged in 

 forty-six genera. Tlie species are distributed tlirough- 

 out all the temperate and colder regions of the world 

 and nuuiy occur within the Tropics. The genus Af/rostis, 

 from which the tribe derives its name and from which 

 comes the word " agrostologist," has about one hundred 

 species, found in all parts of the world, especially in 

 the north temperate zone. Some of our most important 

 meadow grasses — notably Herd's-grass and timothy — 

 belong to this tribe. 



Aristida Linn.* Epicampes Presl.* 



•Stipa Linn. ' Pol jpogon Desf. 



Oryzopsis Michx.* Limuodia L. H. Dewey.* 



Milium Linn.* {Thurheria Benth.) 



Muhlenbergia Schreb.* Arctagrostis Griseb. 



Bracliyelytrnm Beauv.* Cinna Linn." 



Lycunis Kunlh. Agrostis Linn.* 



Pereilema Presl. Gastiidiuni Beauv. 



Heleochloa Host.* Calaniagrostis Roth.* 



Phleuni Linn.* Ammophila Host.* 



Alopecnrns Linn.* Calamovilt'a Seribn.* 



Coleantlnis Seid. Apera Adans. 



Phippsia R. Br.* Lagurus Linn. 

 Sporobolns R. Br.* 



Trii'.k IX. — Aieneti. 



Spikelets two- to several-flowered ; outer empty glumes usually 

 longer than the first floral glume; one or more of the floral 

 glumes awned on the back or from between the teeth of the bifid 

 apex; awn usually twisted or geniculate; the callus, and usually 

 the joints of the rachilla, hairy. 



A tribe comprising twenty-three genera and over 

 three liundred species widely distributed in the tem- 

 perate regions of both the Old and the New World, 

 particularly abundant in South Africa and Australia, 

 a few extending beyond the arctic circle. 



