(84) 



logging operations began to remove this material that at first was 

 regarded as rather inferior. Today hemlock is largely manufac- 

 tured into coarse lumber for outside uses. 



The bark of this tree has long been the principal source of 

 tanning material. Today the tanning industry still depends to a 

 marked degree upon the remaining hemlock forests of the eastern 

 United States for its raw material. 



The needles of the hemlock constitute its main distinguishing 

 feature. On their lower surface they bear two distinct white lines, 

 which give the lower side of the foliage a glaucous or silvery 

 appearance. Other conifers, however, are similarly marked but 

 the needles of the hemlock are smaller and delicate and stand out 

 in two opposite rows on the branchlets. The cones, moreover, are 

 rather small and characteristic. Furthermore, the inner bark on 

 mature trees is generally red, as is betrayed by picking off the 

 outer layers. The trees attain heights of 80 and 100 feet. 



One of the best natural features of the Garden is the Hemlock 

 Grove that borders the Bronx River on both sides as it flows 

 through the Garden. Here a bit of the virgin forest of old hem- 

 locks has been maintained. Behind the large Canada Hemlock, 

 recently mentioned, stands another Siebold's Hemlock. 



The next row begins with the small tree that stands nearest the 

 road of any in this entire group. The row extends at an angle 

 away from the last and contains four plants. The first is 



Tsuga diversifolia, the Hairy-twigged Japanese-Hemlock 



There are but two hemlocks native to Japan, one of which we 

 have already met and this is the other. At first one might very 

 easily confuse them or note no difference, for they are indeed very 

 similar. Closer observation, however, will soon show that the 

 leaves of T. diversifolia are shorter than those of T. Tsuga, giv- 

 ing a rather distinctive appearance and that the branchlets are 

 hairy while those of Siebold's Hemlock are not. There is another 

 specimen of this Hairy-twigged Japanese-Hemlock ahead of us, 

 the first in the next row. 



To the Japanese this species is known as Kotni-tsuga or Kuro- 

 tsitqa. 



