132 MASS. EXPERIMENT STATION BULLETIN 170. 



Fig. 6. — Aveuue of lindens. 



of linden under cultivation which possess distinctive characteristics, and 

 these have been sadly confused bj' nurserymen. The two species most 



commonly planted are T. vulgaris 

 and T. platyphyllos. According to 

 H. J. Koehler,^ T. nulgaris is one 

 of the best trees to plant, while T. 

 platyphyllos is one of the worst. 

 Excellent types of lindens may 

 be seen in the Arnold Arboretum, 

 some of which will perhaps eventu- 

 ually prove superior to either of 

 the above species. 



Horse-chestnut {(Esculus hyp- 

 pocastanum). — • The horse-chest- 

 nut, like the linden, was introduced 

 from Europe, and has been much 

 planted on streets. It grows 

 rapidly, but it is not, as a rule, a 

 long-lived tree. It is affected by 

 a leaf-spot fungus {Phyllosticta) , sometimes losing much of its foliage 

 on this account, and often many of the twigs are winterkilled and affected 

 with Nectria. It is also susceptible to sun scald and frost crack, and 

 the amount of litter produced by the fruit is somewhat objectionable. 

 The red-flowering horse-chestnut is occasionally planted and is preferred 

 by many. 



Sycamore (Platanus occidentalis) . — Fine individual specimens of our 

 native sycamore maj^ often be seen on lawns and roadsides in New Eng- 

 land, but it has been used hi the past to a limited extent for avenue effects. 

 The sycamore has a wide range, being confined in the north to river 

 valleys. It naturally prefers a rich soil, and when transplanted under 

 good conditions it attains a large size. The sycamore will endure any 

 amount of pruning, and can be adapted to any street, even the busiest 

 thoroughfares. Much more use is made of the sycamore than formerly, 

 especially in cities, and the oriental species (P. orientalis) is also much 

 employed. The sycamore is severely affected with a leaf-spot fungus 

 {Gla:osporium) which often causes serious defoliation. The younger twigs 

 sometimes winterkill badly, but the tree will stand a great deal of hard 

 usage and mutilation. 



AiLANTHUS {Ailanlhus glandidom) . ■ — The Ailanthus may be termed 

 a "scavenger tree," as it will grow anywhere and will endure more trying 

 conditions than any other tree. It is frequently found growing along 

 railroad embankments, on dumping grounds, ■ — • in fact, no conditions seem 

 too severe for it. It is used to some extent as a street tree, and excellent 

 individual specimens may be seen here and there. Where quick effects 

 are desired it is worthy of consideration. The Ailanthus, which is a native 



1 Landscape Architecture, July, 1915. 



