BULLETIN NO. 56. 
In the collection of Hawthorns (Crataegus) on the eastern slope of 
Peter’s Hill there are now flowering or soon to flower six hundred and 
thirty groups, including a few duplicates and a few Old World species. 
This collection of American Hawthorns is the result of work carried 
on by the Arboretum during the last fourteen years. During this time 
most of these plants have been discovered, and many of them have 
been named and described. They have all been raised from seeds at 
the Arboretum, and thousands of the young plants have been distrib- 
uted to cultivators in the United States and Europe. This Crataegus 
investigation has meant many thousand miles of travel by officers of 
the Arboretum and by its correspondents and friends, and in the last 
forty years American Crataegus seeds under thirty-two hundred differ- 
ent numbers have been sown, seeds of widely distributed species col- 
lected in different parts of the country having been sown in order to 
show possible geographical variation in the seedlings. This investiga- 
tion has brought to light a large number of beautiful hardy trees and 
shrubs well suited for the decoration of the parks and gardens of cold 
temperate regions; and the collection on Peter’s Hill, already interest- 
ing, should before many years have passed be one of the spectacular 
features of the Arboretum in spring and autumn. American Haw- 
thorns are distributed from Newfoundland and the northern parts of 
the Province of Quebec to Florida and Texas, and to the Pacific Coast 
in the northwest. The largest number of species grow together prob- 
ably on the streams which flow into Lake Ontario both from the north 
and south, in southern Missouri and in southern Arkansas. The genus 
has few species in the Rocky Mountains, and these are small in size 
and not numerous in individuals, and in the northwest there are only 
a few widely distributed species. Some of the American Hawthorns 
are trees which in the rich bottom-lands of the Mississippi valley 
attain a height of thirty or forty, or even fifty, feet with tall straight 
trunks and widespreading branches, many are shrubby in habit, and 
there is one group ( Intricatae ) in which nearly all the species are small 
shrubs rarely more than three or four feet high. These small shrubs 
bear large and showy flowers followed, in the case of many of the 
species, by large, bright colored and abundant fruits. They are valu- 
able and interesting plants therefore for small gardens. In spite of 
all which has been done at the Arboretum to discover and introduce 
these plants, the investigation must be considered as not more than 
fairly begun, for there are still thousands of square miles of territory 
in North America where Hawthorns grow which have not been ex- 
plored with reference to these plants. 
Next to the Lilacs the most valuable shrubs, perhaps, for northern 
gardens now in flower are the Bush Honeysuckles, of which there is a 
large collection in the Arboretum. Many of the large-growing kinds, 
especially forms of the old-fashioned Tartarian Honeysuckle, are con- 
spicuous objects when covered with flowers, and they have the advan- 
tage over the Lilacs of producing in summer and early autumn abun- 
dant crops of brilliant fruits. These Honeysuckles and the Lilacs are 
the most satisfactory shrubs which can be grown in northern regions 
of extreme cold. There are many hybrid Honeysuckles. One of the 
handsomest of the hybrids, Lonicera notha , with pale pink flowers, is 
believed to be the result of a cross of L. tatarica with L. Ruprecht- 
iana of northeastern Asia. There are two large specimens of this 
plant on the right-hand side of the Bussey Hill Road and opposite the 
