DECIDUOUS TREES. 319 



good soil. Half the diseases that now attack old elm trees are the 

 result of the weakened vigor caused by lack of good fresh soil or 

 manure on their roots, which should be put on over the whole area 

 that is covered by the branches. A moist surface soil is most con- 

 genial to the elm. 



THE RED OR SLIPPERY ELM. Ulmus rubra, or fulva. This 

 native elm is so overshadowed by the superior size and beauty of 

 the weeping elm, that it is rarely planted or seen in open ground. 

 It is a treei of a more straggling open head, somewhat similar in 

 form, with out-arching branches, but with much larger and sparser 

 leaves, and without the pendulous spray of the former. It be- 

 comes a tree from fifty to sixty feet high, or about two-thirds the 

 size of the white elm. It is of no value for small grounds. 



THE WAHOO ELM. Ulmus alata. This species may be known 

 by its two longitudinal ridges of cork-like bark on all its twigs and 

 branches, though the white elm and the Dutch elm occasionally 

 have varieties that closely resemble it in this respect. It makes 

 a pleasing tree of medium size, and grows rapidly. Found wild in 

 Virginia and southward. 



The foregoing are American species. 



The following are among the most valued of the great variety 

 of European elms grown in England. Loudon remarks that " the 

 elm is remarkable for the aptitude of the different species to vary 

 from seed ; so much so that it is extremely difficult to say, in this 

 genus, which are species and which are varieties, or even to what 

 species the varieties belong. To us it appears that there are only 

 two sorts which are truly distinct, viz : U. campestris (the English 

 elm) and U. montana (the Scotch elm)." He classes the Ameri- 

 can elms as of the same species with the Scotch, U. montana. 



THE ENGLISH ELM. Ulmus fampestns.The finest trees of 

 this species we have seen in this country are on the Boston Com- 

 mon, where, in grandeur of branching, majesty of trunk, and 

 healthfulness of foliage, they are certainly superior to the white 

 elms growing side by side with them. But it must be remembered 



