184 GRASSES OF IOWA. 



KEY TO THE GENERA OF THE AVENEAE. 



Pedicels of the spikelets articulated below the empty glumes, spikelets 



deciduous, plant velvety Jfolcus. 1 . 



Pedicels not articulated below the empty glumes, which are persistent. 

 Awn of the flowering glume dorsal, inserted below the teeth. 



Flowers all perfect, or the upper ones staminate or sterile. 



Grain sulcate, hairy at the apex Avena." . 



Lower flower staminate, its glume strongly awned; the upper 



perfect Arrhenatherum* . 



Awn of the flowering glume inserted between the teeth. Danthonia.* . 



1. HOLCUS. 



Holcus L. (in part) Sp. PI. 1047. 1753. Endlicher. Gen. PI. 81. Bentham 

 and Hooker Gen. PI. 3: 1159. Hackel in Engler and Prantl. Nat. Pflanz. 

 Fam. II. 2: 53./. 57. Beauv. Agrost. 87. pi. 17. Scribner. Bull. U. S. Dept. 

 Agrl. Div. Agros. 20:89./. 65. 



Spikelets crowded in an open panicle, 2-flowered ; the boat-shaped, 

 membranaceous glumes enclosing and much exceeding the remotish 

 flowers. Lower flower perfect, its papery or thin, coriaceous glume awn- 

 less and pointless ; the upper flower staminate, otherwise similar, but 

 bearing a stout, bent awn below the apex. Stamens 3. Styles plumose to 

 the base. Grain free. (A name in Pliny for a kind of grass, from a 

 Greek word for attractive, of obscure application.) 



Eight species according to Bentham and Hooker; found chiefly in 

 Europe and northern Africa, one, however, reaching the Cape region. 



HOLCUS LANATUS. 



Holcus lanatus L. Sp. PI. 1048. 1753. Watson and Coulter. Gray. Man. 

 Bot. 652. pi. 12. 1890. (6 ed.). Scribner. Grasses of Tenn. Bull. Univ. Tenn. 

 Agrl. Exp. 7: 81./. 106. 1894. Bull. U. S. Depc. Agrl. Div. Agros. 7: 157. 

 /. 151 . 1900. (3 ed.) Beal. Grasses of N. A. 2: 360. 1896. Nash in Britton 

 and Brown. 111. Fl. 1: 168./. j^y. 1896. 



