XVI 



TAP-ROOT 



A TAP-ROOT is defined by Webster as " the root of a 

 plant which penetrates the earth directly downward to a 

 considerable depth without dividing." Nearly all species 

 of trees develop a tap-root in early life some in a modest 

 way, others in a very positive form. The roots seek food 

 and moisture and at once penetrate the earth in search of 

 them. The demand for food and moisture is soon satisfied 

 in some species through throwing out lateral roots, and 

 when this occurs the one tending downward ceases to be a 

 dominant feature. Such trees are designated as " shallow- 

 rooted." In others the tap-root is persistent to a greater or 

 less degree all through life, although lateral roots are de- 

 veloped, and such trees are known as " tap-rooted." There 

 are a number of broadleaf trees that belong to the tap-root 

 class, comprising about all whose seeds are inclosed in a 

 hard shell, as the Oaks, Hickories, Walnuts, Cherries, and 

 Chestnut, while some of the Pines, notably the Longleaf, 

 have a very pronounced tap-root. 



There are a few species, notably Cherry and Ash, that 

 will suffer the destruction of this feature of their root sys- 

 tem without serious results, but for that operation to be 

 successful it should take place when the tree is young 

 best at one year old, or two years at latest. This can be 

 done by removing the plant from the seed-bed to the trans- 

 plant nursery, there to remain until lateral roots are de- 

 veloped, when it can be transferred to the forest. 



Various devices have been tried to prevent the seedling 

 from sending its tap-root downward so far as to make re- 

 moval of the plant difficult. One of these is to place boards, 

 stones, or brick six or eight inches below the surface and 



