SPECIES FOR STREET-PLANTING 53 



live in dry situations as well. It is comparatively free from 

 insect pests and diseases. The hackberry has a peculiar 

 bark, covered with hard, warty excrescences. 



Gingko (Gingko biloba Linn.) (Salisburia adiantifolia) . 

 A new and very promising tree for street use is the gingko, 

 a most remarkable species from China and Japan. It is 

 hardy, and is one of the few trees that is entirely free from 

 enemies of any kind. Its natural shape is pyramidal. The 

 branches have a tendency to hug the central stem, while a 

 few limbs shoot outwardly beyond the general contour of 

 the tree. This mode of branching is not perhaps the most 

 ideal for a shade-tree ; but by careful pruning the limbs can 

 be made to spread and the head of the tree may be trained 

 into a more oval form. One of the most beautiful and 

 striking examples of the gingko as a street-tree is an 

 avenue leading to the Department of Agriculture Building 

 in Washington, Plate 17, Fig. 5. 



The leaf of the gingko is its most curious feature. There 

 is nothing like it in the foliage of trees in America or 

 Europe. It resembles that of the maiden-hair fern, and 

 hence one of the common names of the gingko is the 

 maiden-hair tree. The leaves are two-lobed and parallel 

 veined ; that is, there is no midrib with diverging veins as 

 in our native trees. The veins run nearly parallel with each 

 other from the base to the end of the leaf. The foliage of 

 the gingko turns a clear, golden yellow before it drops from 

 the trees in autumn. 



What may appear strange is that the gingko belongs to 

 the pine family. It is not an evergreen, however, and in 

 this respect resembles the larch and the bald cypress. The 

 falling of the leaves is but an outward and visible sign of an 

 inward structural difference, which removes the pines from 



