ROOT CLIMBERS 



109 



The cracks in the outer tissues, by which the roots 

 break through, can be easily seen with the naked eye. 



These roots grow as they do, because they are insensi- 

 tive to gravity, but like normal roots very sensitive to 

 light. This causes them to grow out from the darker 

 side of the stem, that next the tree, and turn into 

 crevices in the bark. 



Other common garden plants which climb by roots 

 are Ficus SCANDENS, a small creeper, and HOYA 

 CARNOSA, the wax-flower. The English Ivy is also 

 a root climber. Many orchids and a few ferns, though 



FIG. 22 



GLORIOSA SUPERBA 



