MORPHOLOGY OF THE BOOT. 



35 



which the stems, as they grow, ascend walls and the trunks of 

 trees with facility. Iii Rhus a superabundance of these rootlets 

 is produced, thickly covering all sides of the stern. 



60. Epiphytes or Air-Plants also have roots which arc through- 

 out life unconnected with the ground. Epiphytes, or Epiphytic 

 plants, as the name denotes, are such as grow upon other plants 

 without taking nourishment from them. Deriving this from the 

 air alone, they are called Air-plants. This name might be 

 extended to the same or other kinds of plants attaching them- 

 selves to bare walls, rocks, and the like, and unconnected with 

 the soil, though such would not technically be epiphytes. Very 

 many Lichens, Mosses, and other plants of the lower grade, and 

 not a few phsenogamous plants, are in this case. The greater 

 part of the phaenogamous Epiphytes pertain to two mouocotyle- 

 donous orders, the Orchis family and that to which the Pine- 

 Apple belongs, viz. the Bromeliacese. Their thread-like or 

 cord-like simple roots either adhere to the bark of the supporting 

 tree, securing the plant in its position, or some hang loose in the 

 air. Of these, Orchids, i. e. plants of the Orchis family, are the 

 most show}' and numerous, and of the greatest variety of forms, 

 especially of their blossoms, which are often bizarre and fantas- 

 tic. The}' belong, naturally, to climates which are both warm 

 and humid ; the}' are highly prized in hot-house cultivation ; 

 and, along with the hardy and terrestrial portion of the order, 

 they are peculiarly interesting to the botanist on account of the 

 singular and exquisite adaptation of their flowers in relation 

 to insects which A-isit them. In some the blossoms curiously 



FIG. 71. The Banyan-tree, or Indian Fig (Ficus Imlica). 



