HORDED. 635 



floral glume, keels often ciliate. Stamens 3. Styles very short, 

 distinct. Grain narrowly oblong, compressed from the back, often 

 concave on the inside, more or less liairy at the apex, when dry 

 adhering to the palea or free. 



Perennials or annuals, with leaf-blades flat or convolute. Spike 

 terminal, usually stiff, spikelets large. Species 20-30, belonging to 

 temperate regions of America and Europe. 



Bentliam proposed sections as follows : 



1. Agropyron proper, mostly perennials, spikelets more or less 

 distant along the common rachis, outer glumes usually unequal- 

 sided and not keeled. 



2. Eremofyrum Ledeb. — mostly annuals, spikelets distichous 

 and close together in a short dense spike, the narrow empty glumes 

 nearly equal-sided and keeled. 



A. Spike 1 -sided 1 



B. Spike not 1-sided (a) 



a. Florets soft, woolly 2 



a. Florets not woolly (b) 



b. Eootstocks numerous, plant not glaucous. ... 3 



b. Eootstocks present, plant glaucous 4- 



b. No rootstocks (c) 



c. Awns slender, recurved 5-6 



c. Spike long, flexuose, nerves of empty glumes 



conspicuous 7 



c. Like No. 7, only with short erect spikes. . .8,9 

 1. A. violacescens (R_Pouh4). A. caninum (forma) violacescens 

 RrPeimd, Minn. Bot. Studies, Bull. 9 (III) 107 (1894). A. uni- 

 laterale Cassidy, Bull. Col. Agr. Exp. Sta. 12: 63 (1890). A. cani- 

 num unilaterale Vasey, Contrib. U. S. Nat. Herb. 1:279 (1893). 

 A. unilaterale Beau v. is a synonym of Festuca tenniflora Schrad. 



A perennial, 60-80 cm. high; culms strict, smooth. Leaves 

 3-4 in number, sheaths shorter than the internodes; ligule very 

 short; blades rough, involute, pungent-pointed, 5-7 cm. long, 5-12 

 mm. wide. Spike exserted, 1-sided, 7-10 cm. long, 5-8 mm. wide, 

 often purple; internodes of rachis at the middle 3-4 mm. long. 

 Spikelets 3-4-flowered, regularly breaking in pieces, first glume 9 



h' /Ml- 



