ARISTIDA LONGISETA ROBUSTA var. nov. 



A stout, densely tufted form, 8 to 4 dm. liigh, with robust culms, more rigid 

 inflorescence and usually longer leaves than in the species. Empty glumes 

 as in the species except that both are prominently cleft at the apex, bearing 

 in the cleft a scabrous awn about 2 mm. long: flowering glume nearly 

 smooth or only slightly scabrous. 



General distribution.— In dry soil, South Dakota to Kansas, west to Wash- 

 ington and British Columbia. June to Aiigust. 



Specimens examined.— So^j^A Dakota: Aurora Coianty, 35 E. N. Wilcox, 

 August 18, 1890; Redfield, 68 David Griffiths, August 29, 1896; Belle 

 Fourche. 404 Griffiths, August 4, 1897; Canning, 43 Griffiths, August 27, 

 1896; Lebanon, 252 Griffiths, July 23, 1896; Custer, 1118 P. A. Rydberg, 

 August 16, 1892; Rosebud, 34 E. J. Wallace, July 26, 1896. Iowa: Rock 

 Rapids, 410 C. R. Ball, July 6, 1897. Nebraska: St. Helena, 2G29, F. 

 Clements, June 27, 1893; Longpine, 1123 J. M. Bates, August 18, 1898; 

 Osborne City, 156 C. L. Shear, July 9, 1894. Wyoming: Clear Creek, 110 

 Williams & Griffiths, August 5. 1898; Devil's Tower, 517 Griffiths, August 

 12, 1897 ; Whalen Canyon, 54 A. Nelson, July 19, 1894. Montana : Billings, 

 222 Williams & Griffiths, August 30, 1898; Glendive, L. F. Ward, July 21. 

 1883; Missoula, 250 Williams & Griffiths, September. 1898; Indian Creek, 336 

 F. L. Scribner, July 5, 1883 (type) ; Prickly Pear Canyon, 559 R. S. Williams, 

 July 23, 1897. Idaho: T. E.Wilcox, 1881. CWorado ; Colorado Springs, 

 496 S. M. Tracy, 1887. Washington: Alma, 536 A. D. E. Elmer, July, 1897; 

 Rock Island. 439 Sandberg & Leiberg, July, 1893; Spokane, 906 Sandberg, 

 Heller & McDougal, August 16, 1892, also 2597 C. V. Piper, June 25, 1897. 

 British Columlna : Spencer's Bridge, J. Macoun, May 28, 1889. 



This variety can be readily distinguished from the species by its more robust 

 culms, and especially by its rather prominently awned empty glumes. 



ARISTIDA LONGISETA HOOKERI (Trin. & Rupr.). {Aristida j^urpurea 

 hookeri Trin & Rupr. Agrost. 3: 107. 1842). 



A robust form 4.5 to 7 dm. high, with longer leaves and stouter culms than in 

 the species. Leaf -blades rigid, involute, 10 to 20 cm. long. Spikelets some- 

 what larger than in the species, the empty glumes entire or only slightly 

 toothed at the apex ; flowering glume glabrous, or nearly so. 



General distribution.— In dry soil, Texas, New Mexico, and Arizona. May 

 to August. 



Specimens examined. — Texas: No locality, 293 Drummond (cotype); Llano, J. G. 

 Smith, June, 1897, also 6 E. N. Plank, August, 1892; San Antonio, 45 Plank, 

 May, 1893, also V. Havard, 1882; no locality, 11 J. Reverchon, 1881. New 

 Mexico : Mesilla Park, 42 E. O. Wooton, Jime 19, 1897. Arizona : no local- 

 ity, J. G. Lemmon, 1884. 



This variety is evidently related to Aristida longiseta rather than to A. x>nr- 

 purea, and is distingiiished by its larger size, longer leaves, and glabrous 

 flowering glumes. 



ARISTIDA LONGISETA rENDLERIANA (Steud.). {Aristida fendleri- 

 ana Steud. Syn. PI. (4ram. 420. 1855; ,1. 2)nvparea fendleriana Va.sey 

 Contr. U. S. Nat. Herb. 3: 46. 1892; .1. fasciculata fendleriana Vasey in 

 Beal, Grasses N. A. 2: 207. 1896.) 



A densely tufted form 2 to 4 dm. high, with simple, erect cnlms, numerous invo- 

 lute basal leaves and much shorter settf than in the species. Panicles strict, 

 few-flowered. Empty glumes unequal, acute, generally cleft at the apex and 

 bearing a short awn ; second glume ecjualing or slightly exceeding the some- 

 what scabrous flowering glume. Setaj subequal, 2 to 3 cm. long. 



