375 
Phznological Notes. 
By L, H. PAMMEL. 
A paper read before the Iowa Academy of Science, December, 1891. 
One of the points too often neglected in working up our flora 
is the relation that climate bears to plants. It is a question, too, 
that is of interest to horticulturists and agriculturists. Especially 
so when we take into consideration our cultivated plants. Few 
authors in working out our floras have touched upon this matter. 
Mr. Frederick Brendel‘ is one of the few who has given dates 
and time of ripening of seed of cultivated plants, as well as other 
phenological notes. Among the authors of our local floras who 
have given such data, I may mention W. R. Dudley,? Lester F. 
Ward, ?* Britton, Trelease,* Henry,® Halsted °. 
European investigators have been much more active in this 
direction. Extensive monographs and papers have been pub- 
lished by Fritsch,? Quetelet,’ Lachmann,® Ihne,!° Hoffmann, 1! 
Sic. 
This paper has been divided up into— 
I. A succession of flowers for the years 1886 and 1891. 
The dates of the first appearance of flowers for 1886 are based 
_ on the observations of Halsted. In 1891 a large number of data 
_ were made by myself and P. H. Rolfs, but I have only selected 
_ some of them. 
II. A comparison of the appearance of the flowers, leaves, 
_ @tc., for the years 1886 and 1891. The observations of 1886 are 
_ based on those made by Richman under Halsted’s '? direction. 
Those of the spring of 1891 were made under my direction by 
Eugene Brown, a special student in botany. 
III. Some notes on falling of leaves, especially as influenced 
by frost. Also a few notes on the effects that frost had on some 
_ plants—here again, not to make the paper too lengthy —a large 
- number of observations are omitted. The observations were 
made on plants in a small garden, so that the conditions were 
nearly the same. These notes would be more valuable if exact 
‘temperatures had been recorded, as Fritsch has done. We 
hope to continue our observations next year, and keep a record 
of the temperature. 
IV. Some notes on late flowering plants. 
