306 Rydberg: Studies on the Rocky Mountain flora 



This species is closely related to U. cardiophylla Rydb. but 

 differs in its narrower leaf blades, shorter petioles, longer and 

 denser inflorescence, and longer sepals. In habit it closely re- 

 sembles U. gracilis but differs in its practically glabrous stem and 

 thinner and more glabrous leaves. 



Montana: Emigrant Gulch, Aug. 23, 1897, Rydberg & Bessey 

 3935 (type, in herb. N. Y. Bot. Garden); Jack Creek Canyon, July 

 15, 1897, J9J($,- Jocko Creek, June 10, 1901, D. T. MacDougal 2y5; 

 Melrose, July 6, 1895, P. A. Rydberg 2612; Lima, Aug. 6, 1895, 

 Rydberg 261 j. 



Wyoming: Halleck Canyon, July 4, 1900, Aven Nelson 7444. 



Idaho: Priest Lake, July 28, 1900, D. T. MacDougal 235; 

 Cooper's Warm Springs, July 1892, Isabel Midword. 



Alberta: Rocky Mountains, 1858, E. Boiirgeau. 



Parietaria occidentalis sp. no v. 



Annual ; stem slender, erect, simple or branched at the base, long- 

 villous, 1-4 dm. high; leaf blades thin, light green, lanceolate, 

 acute at the base, obtuse at the apex, 1-4 cm. long, 5-18 mm. wide, 

 sparingly pubescent; bracts of the involucre linear, obtuse; sepals 

 oblong or lance-oblong, obtuse or acutish. 



This species is related to P. pennsylvanica Muhl. but differs in 

 the long hairs of its stem, light green color, and the more obtusish 

 sepals. It grows in moist shaded places. 



Idaho: Clearwater River, Nez Perces County, May 14, 1892, 

 Sandberg, MacDougal & Heller 176 (type, in herb. N. Y. Bot. 

 Garden) . 



Washington: Wawawai, May 1897, Elmer 755; Alamota, 

 June 1893, Piper 1507. 



Nevada: East Humboldt Mountains, August 1868, 5. Watson 

 1084. 



POLYGONACEAE 



Eriogonum biumbellatum sp. nov. 



Suffruticose perennial, branched at the base; leaves basal, 

 clustered at the ends of the short branches, 2-5 cm. long, short- 

 petioled; blades oblanceolate, finely tomentose on both sides when 

 young, soon glabrate and green on both sides; scapes 2-3 dm. high, 

 sparingly tomentose; involucres in compound umbels; bracts 

 verticillate, similar to the lea\'es but smaller; involucres with a 



