SHREVE 



Plate 33 



te&. 



'* ?w 



A. Open Forest on summit of Mount Lemmon, at 9,000 feet, with gtxnl reproduction of Pinus arizonica and 



a close stancl of Duyaldia hoopcsii. 



B. Mature thicket of Populus tremuloides on summit of Mount Lemmon at 9,100 feet. In foreground are 

 Pteris aquilina var. pubescens and flowering plants of Frasera speciosa. 



