8 FAMILIAR LESSONS IN BOTANY. 



seek the soil, but attach themselves to other plants, to the 

 sides of buildings, etc. They are more useful to support 

 the plant in its place than to nourish it, and they thus 

 ])erform the work of tendrils. Of this class is the Virginia 

 creeper, Bignonia grandiflora. A proof that its aerial 

 roots are not feeders is, that it never injures the tree to 

 which it attaches itself, any more than the grape or any 

 other air-rootless creeper. 



10. The third class of air-roots do not attach themselves 

 to anything, but hang from tlie plant like seemingly use- 

 less threads. These roots draw nourishment from the air, 

 and a plant so fed will continue to grow for years in a 

 suitable atmosphere, merely suspended in a room. These 

 are called EpiiJiliytes, from the Greek word epi, upon, and 

 pliuein, to grow. I have seen a leaf of this kind transfixed 

 to the side of a plastered wall, pretty much as an entomol- 

 ogist would secure a bug. There it threw out roots from 

 the terminal point of each primary vein, and in a few weeks 

 the whole margin of the leaf was adorned with tiny plants, 

 fed by these air-rootlets. Spanish moss, Tillandsia 

 usneoides, is an epiphyte. 



11. In the mistletoe (Viscum flavescens) we have an 

 example of roots that fix their abode upon and draw 

 nourishment from other plants. These are called parasites, 

 from the Greek pamsitos, which means an eater at the 

 table of another, that is, to be fed or nourishe'd by another. 

 These plants oft^n destroy the tree upon which they fix 

 themselves. 



12. Roots when found growing in water are called 

 aquatic {radix aquatica). I gave you the derivation of root 

 from radix. I will now tell you that aquatic comes from 

 aqua, which signifies water. Some of the aquatic roots 



10, Is there still another class of roots? Their names? What is the name 

 Epiphytes derived from ? 



11, How docs the mistletoe grow? What are these kinds of plants called? 

 Its signification ? Do they injure the tree upon which they grow ? 



118, Roots, when growing in water, arc called what ? Derivation of aquatic? 



