Development of the Vegetation of New York State 67 
them as indicator species taken in the large; for example, 
sweet gum and persimmon and willow oak suggest a warm 
temperate zone; balsam and red spruce and paper birch a 
cool temperate zone or even “ boreal conditions.” In a 
relatively small area like New York, selected on a purely 
arbitrary basis, zonal differences may not be very obvious 
(except where notable differences of elevation are taken), 
still it is of very vital concern to the farmer, the fruit grower, 
the nurseryman, arboriculturist, the landscape architect and 
even the forester to know as minutely as possible the climatic 
or zonal relations of his region. 
It will be understood therefore that these zonal designa- 
tions are not offered as a final expression of the floristic rela- 
tions of the New York area — that is precisely one of the 
important lines of investigation to be undertaken in connec- 
tion with or as a result of the botanical survey of the State 
above referred to — but as an effort to orient ourselves with 
respect to the present status of plant distribution over the 
country at large and always with the implication that what 
we observe must be seen in the light of paleobotanic as well 
as of geologic history in order to reach the more satisfying 
interpretation of it. 
As previousl, y mentioned, we commonly look upon our flora 
as possessing two contrasting elements; on the one hand the 
boreal plants whose greatest development is upon Canadian 
territory. It is especially the northern coniferous forest 
region. We regard the higher Catskills and the Adirondacks 
as being a part of this region. On the other hand, the austral 
plants whose region of greatest development lies along the 
Appalachian axis to the south and to the southwestward 
through Tennessee and Arkansas to Eastern Texas. On this 
meeting ground, which from this point of view really com- 
prises most of the State, is a forest flora which is neither 
strongly austral nor strongly boreal but as Merriam ? calls it, 
transitional. It may be said fairly to reach its maximum 
development in the New York type of environment. This is 
1 Merriam, C. H. Life Zones and Crop Zones. Bull. U. S. Biol. 
Surv., 10:1897. 
