98 UNIVERSITY OF MISSOURI STUDIES [246 



Sub-class 2. DICOTYLEDONES. 



Series i. CHORIPETALAE. 



Order 15. SALICALES. 

 Family 28. SALIC ACE AE Li n d 1 . Willow family. 

 112. POPTJLUS L. POPLAR. ASPEN. COTTONWOOD. 



289. P. tremuloides aurea (Tidestrom) Daniels, Nov. comb.* 

 AMERICAN ASPEN. 



Throughout the foothills and mountain region except at the 

 higher elevations, 5800-10000 ft. (Daniels, 314). 



NEWFOUNDLAND to HUDSON BAY and ALASKA; NEW JERSEY 

 and TENNESSEE to MEXICO and LOWER CALIFORNIA. 



290. P. Sargentii Dode. [P. occidentals (Rydb.) Britton; 

 P. deltoides occidentalis Rydb.]. WESTERN COTTONWOOD. 



Common along streams, ascending Boulder creek as far 

 as Eldora, 5100-8600 ft. (Daniels, 820). Also at Lyons 

 (Rydberg). " 



SASKATCHEWAN to MONTANA; KANSAS to ARIZONA. 



291. P. acuminata Rydb. BLACK COTTONWOOD. 



A solitary tree near a stream about half way between 

 Boulder and Marshall, 5400 ft. (Daniels, 819). Common in 

 all gulches; there are large trees in Sunshine Canon, 6500 ft. 

 (Ramaley). 



SOUTH DAKOTA to IDAHO; NEW MEXICO to NEVADA. 



292. P. angustifoHa James. NARROW-LEAVED COTTONWOOD. 

 Along streams and in canons on the mesas and in the 



foothills and mountains, 5400-9000 ft. (Daniels, 52). 



NORTH DAKOTA to WASHINGTON; NEW MEXICO to CALI- 

 FORNIA. 



293. P. balsamifera L. BALSAM POPLAR. 



Fourth of July mine; Eldora; Allenspark, 8000-10000 ft. 

 (Ramaley). 

 LABRADOR to ALASKA; NEW ENGLAND to COLORADO. 



*See Appendix A. 



