58 Forest Club Annual 



ornatus also covered areas of 50 to 75 square yards with its 

 low bluish-green individuals. These groups are very distinct 

 because of the color and more or less matted form, of the 

 plants. Species of Symphoricarpos, Prunus, Rhus, and Rosa 

 were becoming evident as shoots from unburned root systems. 

 Macrocalyx nyctlea was abundant in the clayey situations and 

 Lygodesmia juncea in the more sandy places. Besides these 

 shrubs and herbaceous plants there were a number of species 

 of grasses that gave character to the new vegetation over 

 restricted areas. On the east side of the canyon the fire did 

 less damage to the ground cover and the trees were not so 

 badly scorched. The sod was not so badly killed out so that 

 the invasion of the Dogbane was not especially noticeable there 

 except in small areas where ground cover destruction was 

 conspicuous. 



From the lower portions of the slopes the coniferous in- 

 habitants frequently invade the third and climax formation 

 of the region, the mesophytic canyon bottoms. A rather large 

 number of grasses and other herbaceous species of the moister 

 forests, as well as a few shrubs have also wandered from the 

 deeper shade and have become established among the pines on 

 the lower stretches of that formation. It often happens that- 

 such plants as these make up the bulk :of the ground cover 

 on the lower slopes, while on the upper slopes most of the 

 ground cover species have wandered in from the ridge forma- 

 tion above. The pines are, however, few that are found in the 

 moist soil of the canyon bottoms through which a small, clear 

 stream usually runs. 



Just as the ridges are tongues of upland cutting through 

 the esciarpment so the canyon bottoms are usually narrow 

 tongues of lowlands extending from the heads of the canyons 

 to the Hat Creek basin north of Pine Ridge. In these places 

 a deciduous forest formation contrasts very sharply with the 

 conifer covered slopes a.bove. Viewed from high up the slope 

 these tortuous light green lines are very clearly differentiated 

 from the dark green pines on both sides. The important char- 

 acteristic tree species in these places are Populus fremontii, 

 Populus tremuloidcs, Acer negundo, Fraxinus lanceolata , 

 Ulmus americana, Celtis occidentalis, Salix nigra, Acer glabrum 

 and Betula occidentalis. Smaller trees such as Prunus ameri- 



