MOST AVAILABLE TREES FOR PLANTING. 59 



gelm) grows more upright and is sometimes used as a shade 

 tree, yet its large tender leaves, susceptible to frost as well 

 as to burning by reflected heat, make it undesirable. The 

 Japanese species (Calalpa bungei and C. kaempferi) are 

 purely ornamentals of small size. 



CHESTNUT. 



This is a large tree of very rapid growth (Costarica den- 

 iaia, Borkh), and formerly was one of the most valuable na- 

 tive species, but since the appearance of the bark disease (see 

 page 101), not a single chestnut tree should be planted any- 

 where. The paragon, or large fruited chestnut, from Europe 

 is advocated for its nuts, but it is apparently susceptible to 

 the same disease. 



ELM. 



Xo other tree, native or foreign, combines so many de- 

 sirable qualities for a street tree as the American, or white, 

 elm (Ulmus Americana, L.) It grows too large for narrow 

 streets, but for those of moderate width, and for avenues, it 

 has no superior. The trunk commonly divides at from ten 

 to fifteen feet above the ground and forms a broad, high- 

 arching crown with pendent branchlots. The tree requires 

 reasonably good soil and plenty of moisture, and under fa- 

 vorable conditions grows comparatively rapidly. The leaves 

 are rather small and the shade produced not too dense. The 

 autumn foliage is not notable. White elm is subject to 

 several diseases, but throughout 2^ew England, and in this 

 State, its chief enemy is an insect called the elm leaf beetle. 

 (See page 67.) This, however, should not deter anyone 

 from planting the tree for the insects can always be con- 

 trolled. Slippery elm (Ulmus fulva, Michx.), and other na- 

 tive species have no especially desirable qualities as shade 

 trees. The English field elm (Ulmus campestris L.) and the 

 Scotch elm (Ulmus monlana, Bauh.) are sometimes planted 

 as ornamentals. 



