ECADS. 



Ill 



obl que laterals. In fact, the larger roots also sometimes take an oblique 

 course. As indicated in the figure, the root system is somewhat meager. The 

 older roots may be identified by their brownish-yellow and somewhat flaky 

 cortex and the tough, rope-hke stele within, while the younger roots can be 

 told by the clustered arrangement of their branches. 





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Fig. 51. — Root systems of ecads of Chamcmerium angustifolium: a, gravel-slide; 6, forest. 



A number of plants were examined on a steep gravel-slide. Like those 

 in the fir forest, thej^ were mature and in full bloom. Those on the gravel- 

 sUde ranged from 1.5 to 2 feet in height, while the shade forms were 4 to 5 

 feet tall. The most noticeable differences in the underground parts were 

 the shallowness and linear extent of the root systems and the remarkable 

 difference in number and fineness of the smaller roots. Of the several plants 

 examined on the gravel-slide, all sent roots up the slope at a depth of 2 to 

 10 inches or more. These frequently ran rather parallel with the surface, 

 often branching iuto major branches, for a distance of 3 to 6 feet or more. 

 From these rather shallow roots some of their branches pursued an obliquely 

 downward course. None of them reached a depth greater than 20 inches, 

 but almost invariably turned and ran parallel with the surface of the soU. 



A comparison of the two root systems emphasized the paucity of small 

 laterals in the forest ecad and their abundance in the gravel-slide. In the 

 latter habitat, great clusters of fine rootlets (resulting from the repeated 



