OF SOME SPECIES AT THE EDGES OF THEIR RANGES 27 
years ago by John M. Bigelow, an able botanist, thus affording 
an exceedingly interesting basis for comparison of present with 
past conditions. 
Although the Sugar Grove area lies at the end of the long lobe 
of the Alleghenian Floral Area which Merriam’s* map shows 
stretching into northeastern Ohio, the plants which terminate 
here are by no means all Alleghenian but include species of varied 
geographical affinity stretching away from the area in all directions 
as was shown in a preceding paper.t 
It must be pointed out at the outset that the list of plants here 
given as reaching their territorial limits is by no means a complete 
or final catalogue. From the nature of the case it will be subject 
to a considerable amount of revision as the flora of the country 
becomes better known. When the manifold sources of error 
which enter into the study are taken into consideration the results 
might almost be said to have been reached by the multiplication 
of uncertainties. Nevertheless it is believed that present knowl- 
edge is sufficient to justify their publication for, however much the 
status of individual species may be changed by later discoveries, 
it does not seem likely that the general outlines of the account here 
presented will require much readjustment. The first source of 
error lies in the fact that as the flora becomes better known plants 
which are not now known beyond the borders of this area may be 
found in adjoining counties, thereby being removed from the list. 
In view of the fact that the Sugar Grove area has been more 
thoroughly worked than the surrounding territory the number of 
these may be somewhat large. Plants new to the area may be 
‘discovered and added to the list. But probably more important 
than changes due to either of the above causes will be the addition 
-of numerous species, now reported from the region, whose ranges 
are not yet known with sufficient accuracy to enable us to tell 
whether they here reach their limits or not. In this category are 
many groups of plants which have not been collected thoroughly 
enough in Ohio to justify any deductions as to their distribution. 
Many groups are so difficult of identification that only the deter- 
Unite Satna Dee 
* Merriam, C. Lif d 
Agr. Biol. Survey Py 10. 1898 
riggs, Robert F. Observations on the geographical composition of the Sugar 
Grove Flora. Bull. riches Club 40: 487-499. f. I-10. 10S 1913. 
