546 Piper : Agropyron tenerum and its allies 



We were quite unable to find any other character associated 

 with a hairy rachilla, and therefore believe it to be wholly illusive 



as a specific distinction. 



. The multiplying of names based on varying combinations of 

 these slight characters seems to us undesirable. We would inter- 

 pret the value of these characters practically by the following 



arrangement : 



A. TEXERUM Vasey. 



A, tenerum majus Vasey. 



A, pseudorepens Scribn. & Smith. 



A, Ntwae-Angliae Scribn. 



A- tenerum trichocoleura nom. nov. 



A. tenerum ciliatnin Scribn. & Smith. 

 A. TENERUM LONGiFOLiUM ScHbu. & Smith. 

 A. tenerum magnum (Scribn. & Smith). 



A. pseudorepens magnum Scribn. & Smith. 



Agropyron biflorum 



Agropyron biflorum (Brign.) R. & S. Syst. 2 : 760. 1817. 

 Triticuni biflorum Brign. Fasc. Rar. PI. Foroj. 18. 18 10. 

 Triticum violaeeum Hornem. Fl. Dan.//. 20^4,. 1832. 



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Agropyron violaeeum Lange, Consp. Fl. Groenl. 155. 1880. 



Following Ascherson & Graebner (Syn. Fl. Mitteleur.), we 

 take up the above older name for what has usually been called 

 Agropyron violaeeum. This species is distinguished with some 

 difficulty from A. tenerum. The characters of the two species 

 may be thus contrasted : 



A. biflorum: Florets 2-5 ; lower empty glume usually 3- 

 nerved ; flowering' glume usually broadest above the middle, 

 rather soft in texture ; joints of the rachilla usually hairy ; spikes 

 dense, seldom exceeding 4 cm. in length ; leaf-blades flat, soft, 

 usually short and rather broad ; upper sheaths often inflated. 



A. tenerum: Florets '^^-'J \ lower empty ^lume usually 5- 

 nerved ; flowering glume usually broadest below the middle, firm 

 in texture ; joints of the rachilla usually puberulent ; spikes often 

 loose, usually 5-20 cm. long ; leaf-blades flat or involute, elon- 

 gate ; upper sheaths not inflated. 



None of the above differences is constant, but they serve fairly 



