28 
NATURE STUDY. 
The Local Flora. 
BY FREDERICK W. BATCHELDER. 
The formation of an Institute, like ours, will give, has already 
given, a perceptible impetus to the study of the local flora. 
But what is a local flora ? Do not about the same plants 
grow commonly everywhere ? Shall we not find violets and 
oaks and grasses and so on everywhere we go? 
The flora of any given district does, to be sure, contain many 
plants which are common everywhere ; but the difference be¬ 
tween the sum total of plants in even adjoining districts are 
greater than one who had not studied the subject could suspect. 
There is a large number of plants common through extensive 
districts, a smaller number common only in restricted areas, a 
still smaller number which may be called strictly local. 
The causes of the irregular distribution of plants are not yet 
well known. The new branch of botanical study now called 
“ ecology,” that is, the relation of a plant or species to its envi¬ 
ronment, is an attempt to follow up this subject in a syste¬ 
matic way. 
To take an example right at home. At Manchester we have 
eight species of oaks, a remarkable number, particularly when 
growing as we find them on the west side of the river, all within 
the compass of a square mile. A few miles further north or 
south we find only two or three species. Why is this ? Then 
as to the violets. Why have we not the Canada violet, and the 
long-spurred and the striate violets when they grow abundantly 
in adjoining districts ? The grasses, which from their nature 
are subject to general distribution, are also governed by laws 
which we cannot yet formulate. We are continually meeting 
surprises, a northern grass here, a southern grass there, appar¬ 
ently out of place. Bear in mind I am speaking only of grasses 
which grow spontaneously, and not of such as are introduced 
accidentally, or by the direct agency of man. 
So in the study of the local flora many elements of surpassing 
