iv 
brought to light. But since 1875 the study of botany has undergone 
many changes, and its present day problems differ greatly from those 
of former times. The systematist’s conception of a species has also 
changed, a finer discrimination in determining species being required 
at the present time. The nomenclature question, the constant split- 
ting up of species and the revision of families and genera are render- 
ing the subject more perplexing and less fascinating to at least the 
true nature loving botanist. 
In the present instance it has been our intention to bring the flora 
up to date and modify its scope to include the three counties com- 
prising the Connecticut valley. These counties, whose boundaries are 
fairly uniform, represent a section extending from Connecticut to the 
New Hampshire and Vermont lines. The Connecticut valley forms 
a distinct area differing quite widely in its soil and climatic conditions 
from other sections of the state, the elevation ranging from less than 
100 feet to only a few hundred feet. Here the elm reaches its great- 
est perfection, and on the higher slopes the rock maple finds its most 
congenial environment. The eastern part of the territory resembles 
that of Worcester county, and the general elevation ranges from 400 
to about 1,200 feet; while the western section, which has an elevation 
of 800 to 2,200 or more feet, and which is farther from the coast, re- 
sembles in many ways southern Vermont. On the higher elevations 
of our western range the golden hawkweed becomes a pest in fields, 
as in Vermont, although in the Connecticut valley this plant is not 
common enough to be a nuisance. Here, too, the soil conditions are 
more primitive, therefore humus plants are found more abundantly 
than elsewhere in the state. In this region grow forests of beech and 
red spruce, and the balsam fir and hackmatack are common. 
The diversified forms of plants which characterize a region and 
which we term its flora, represent adaptations to a more or less con- 
genial environment, and even during the relatively brief period of 
the settlement of New England many of our introduced plants 
undoubtedly became modified to a certain extent. Even species 
which are adapted to a much warmer climate than our own frequently 
prove themselves as hardy as our native species, whereas on the other 
hand, quite a few of our native trees, like the sycamore and others, 
are often affected by winter killing. 
There are many tactors which play an important part in the distri- 
bution of plants of which we know little, and the problems involved 
are difficult of solution. Variations in the humus content, in the soil 
moisture or light intensity, may completely exterminate a species in a 
given locality. Continued deforestation has greatly modified our 
flora, many species having become rarer. Humus has played a very 
important role not only in affecting the predominence of certain 
