200 TkANSACTIONS OF ROVAL SCOTTISH ARBOKICUI.TURAL SOCIETY. 



Intermediate. 



Finns iaeda (loblolly pine). 

 Finus virginiana (scrub pine). 

 Finns rigida (pitch pine). 

 Finns strobus (white pine). 

 Castauea dentata (chestnut). 

 Qneirns alba (wliite oak). 



Betnla lenta (river birch). 

 Bettila Intea (yellow birch). 

 Jngians nigra (black walnut). 

 Magnolia tripetala (umbrella-tree). 

 Magnolia acuminata (cucumber-tree). 



Most Important Species ix Central New York. 



[Beginning with the most tolerant.] 



Ulmus ainericana (white elm). 



Acer rtibrnni (red maple). 



Finns strobus (wliite pine). 



Quercns alba (white oak). 



Quercns platanoides (swamp white 



oak). 

 Quercns rubra (red oak). 



Quercns coccinea (scarlet oak). 

 Quercns velutina (yellow oak). 

 Castanea dentata (chestnut), 

 Hicoria (hickories). 

 Quercns prinus (chestnut oak). 

 Fraxinns ainericana (white ash). 

 Juniper ns virginiana (red cedar). 



In actual practice there is seldom any doubt as to the light 

 requirements of the extreme members of the tolerance scale. 

 The doubt comes with species which, under certain conditions of 

 climate and soil, may be classed either as tolerant or intolerant. 

 Instead of dividing species into "very tolerant," "tolerant," 

 "intermediate," "intolerant," and "very intolerant," it would 

 therefore be more simple and ])ractical to divide them into only 

 three groups — "tolerant," "partially tolerant," and "intolerant." 

 This classification does not, however, preclude the possibility 

 of species with extreine requirements becoming, under certain 

 conditions of climate and soil, partially tolerant. Thus, 

 beech and fir, which are ordinarily very tolerant, on very 

 poor soil and in a very cold cliinate may become only partially 

 tolerant ; and, on the other hand, pine and larch, which are 

 ordinarily very intolerant, in very favourable soils and climates 

 may become partially tolerant. 



To the group of tolerant trees belong the following genera : — 

 Taxus, Fngus, Abies, Puea, Tsuga, Pseudotstiga, Thuja, Aisculus, 

 evergreen oaks and other evergreen broad-leaf trees, and others. 



To the group of partially tolerant trees belong Carpinits, 

 Ti/ia, Acer, Fraxinus, Ulmus, Alnus, the five-needled pines, 

 Cliamcecyparis, Libocedrus, Sequoia, white oaks, and others. 



To the group of intolerant trees belong the black oaks; the 

 two and three needle pines, such as Fiiius contorta, P. jrffreyi, 



