Complimentary 
NEW SERIES VOL. I 
NO. 5 
ARNOLD ARBORETUM 
HARVARD UNIVERSITY 
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N».. •• VORJC 
BUl.ANICAL 
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OF 
POPULAR INFORMATION 
JAMAICA PLAIN, MASS. MAY 26, 1915 
Hawthorns. Hawthorns ( Crataegus ) have been in flower in the Ar- 
boretum during- the last two or three weeks, and others will flower in 
succession until nearly the first of July; on some of the species the 
fruit ripens in August and on others as late as November; and in a 
collection of these trees and shrubs there is much beauty of flower 
and fruit to be seen during more than half the year. The genus is 
more largely represented in species and in the number of individuals 
in eastern North America than in other parts of the world; a few 
species are found in the Rocky Mountain region and in the Pacific 
states; there is a single species in Japan, and less than twenty in all 
continental Asia. There are, however, several species in southwestern, 
southern and central Europe and two species in western Europe. Be- 
fore 1900, when the study of American Hawthorns was begun seriously 
at the Arboretum, little was known about the American species which 
had been singularly neglected by American botanists and American 
gardeners. Several specips, however, had reached Europe at the time 
when European plant collectors were sent to America, and a few 
American species had been described by European botanists from 
plants cultivated in European gardens. Twenty years ago plants raised 
from seeds collected principally in Missouri and Arkansas in 1880 be- 
gan to flower in the Arboretum and could not be referred to any of 
the species which had been previously described. This led to a sys- 
tematic study of the wild plants in many parts of the country, and to 
the bringing together here of a large amount of material. During the 
last fifteen years many species have been described at the Arboretum 
by authors working independently, and Mr. Dawson has sown the seeds 
of 3306 Hawthorns gathered in the United States from wild plants. 
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BULLETIN 
