XV. 



THE LARCHES, CEDARS, GINKGO AND TEW. 



The length of time that coniferous evergreens will 

 retain their leaves varies much and is controlled, not 

 only by the habit of the species, but also by the condi- 

 tions under which the individual tree may be growing. 

 This applies to all plants which are evergreen as well as 

 to the coniferous species. Rhododendrons, growing 

 naturally in the mountains of North Carolina, in deep 

 soil and a comparatively even temperature, may hold 

 their leaves for seven or eight years ; but the same 

 plants removed to our climate and left to care for 

 themselves under unsuitable conditions, with the dry 

 heat of our summers and the drier cold winds of our 

 winters, would not, perhaps retain their leaves more 

 than three or four years, even if the plants themselves 

 did not die. 



It is an easy matter to count the nodes of annual 

 growth of evergreens where the leaves are still attached, 

 especially on the coniferous trees, and thus ascertain 

 exactly the number of years the leaves have remained 

 on them. The leaves of the spruces and firs will be 

 found attached to branches several years old, and I 

 have counted those of the Austrian pine back for five 

 seasons. The leaves of the white pine fall in the 

 autumn, at the same time those of the broad-leaved 

 trees are falling ; the leaves of one season's growth, 

 however, remaining on the tree through the winter and 



