284 A COMPARISON OF THE 



FIG. 70. Fio. 71. FIG. 7*. 



CONICAL TREES. This term is sufficiently explicit, and includes 

 all those trees of flatly conical form which are usually called 

 pyramidal. The latter term refers to those members of the conical 

 class which have a breadth about equal to their height. The pear 

 tree, Fig. 71, among deciduous trees, is a type of the pyramidal 

 form. 



The Norway spruce and hemlocks, Fig. 72, are types of conical 

 forms. Most species of poplar (the Lombardy poplar being an 

 exception) have the pyramidal-conical form while young, but with 

 age they round out into trees of the first class. The Balm of 

 Gilead poplar, and the cucumber tree, are good examples of com- 

 pact deciduous trees of this class when young, but they all become 

 round-headed trees at maturity. 



Nearly all evergreens are conical when young, and very many 

 of deciduous trees also. Few of the latter, however, retain this 

 character after they are full grown. The white pine when quite 

 young is an open-limbed conical tree ; but when twenty years old, 

 if it has grown in congenial soil, and an open exposure, it 

 assumes an ovate-pyramidal form, with the rounded masses of 

 foliage that characterize round-headed trees, but retains otherwise 

 the general outlines of the conical class in its after growth. The 

 yellow or northern pitch pine (P. rigida) changes from a straggling 

 conical form when young, to an irregularly branched oblate-headed 

 tree in age. The Scotch pine, which is ot a rounded conical form 

 when young, becomes, with age, as picturesquely rounded as the 

 oak. The scarlet oak, Fig. 64, is a good example of a straggling 

 conical form when young, though it becomes a loose round-headed 

 tree at maturity. 



