81 
torical Society dating back to the early decades of the nineteenth 
century and that of the Brooklyn Institute, our herbarium has 
much of historical interest as well as widely representative ma- 
terial for the routine identification of plants of the United States. 
There is great need and desirability of special collections, and I 
think it should be the policy of the herbarium to develop a few 
restricted groups rather than a general herbarium. During the 
past two years we have been especially interested in getting col- 
lections of cultivated plants; an adequate herbarium seems the 
only solution for the present chaotic conditions in the names and 
identity of cultivated herbaceous plants. 
LocaL Fiora SECTION 
With the exception of the limestone ledge still desired for the 
growth of walking fern, maidenhair spleenwort, and similar rock 
ferns, the ecological groups may be said to have reached a certain 
degree of maturity. The grove of young trees planted in 1918 has 
taken on the appearance of a small forest, in which the interlacing 
branches provide good shelter for many hundreds of white tril- 
liums, spring beauty (Claytonia), hepatica, and violets. Each 
year substantially improves the woodland conditions by increasing 
the shade, humus, and aeration of soil. The grove consists of 
trees planted about & ft. apart in a level well-drained area. The 
trees were of approximately equal size when set out, and were 
placed with the idea of seeing which species would survive. The 
rapidity of growth may be roughly seen in the following average 
measurements made in December 1933 of the circumference at 
two feet above the ground: Liriodendron (17.5 in.), Quercus 
rubra (17.5 in.), Quercus velutina (16 in.), Betula papyrifera 
(14 in.), Fagus grandifolia (11 in.), Acer saccharum (10.3 in.), 
Pinus Strobus (10.5 in.), Betula lenta (10 in.). The total num- 
ber of trees was 65. Of these species Liriodendron is by far the 
fastest growing, although it is probably exceeded in rate of growth 
by the sweetgum (Liquidambar). Acer saccharum, Pinus Stro- 
bus, and Betula lenta appear unable to stand the strong com- 
petition of the other species. Betula lenta and B. lutea grow well 
when removed from competition. 
IExcept for hemlocks and flowering dogwoods which are still 
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