ROOTS 



269 



in almost any greenhouse. Clinging to the trunks of trees, 

 usually imitated in the greenhouse by nests of sticks, they 

 send out long roots which dangle in the moist air (Fig. 230). 

 Such plants are called epiphytes, the name indicating that 

 they perch upon other plants and have no connection with 

 the soil (Fig. 231). A very common epiphyte of our South- 

 ern states is the common long moss or black moss (although 



I 



FIG. 231. A group of epiphytes in a tropical forest. After KARSTEX and 



SCHENCK. 



it is by no means a moss) that hangs in stringy masses from 

 the branches of live-oaks and other trees (Fig. 232.) 



147. Summary. The root receives water and salts from 

 the soil, and incidentally anchors the plant. The structure 

 of its vascular cylinder is very different from that of the stem 

 cylinder. The phloem does not occur between the xylem 



