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species, and southward along the Appalachian Mountains and in the 
southeastern states species of Crataegus are not rare. The species 
have now been arranged in twenty-three groups distinguished by the 
shape and character of the leaves, the size of the flowers and the size 
and shape of the fruit, and it is interesting that while species of some 
of these groups are widely and generally distributed those of others 
are chiefly confined to particular sections of the country, as the Flavae 
to the southeastern states, the Douglasianae to the northwest, and the 
Tenuifoliae to the northeastern and middle states. The Macracanthae, 
which is one of the common northern groups, with many large trees, 
is extremely rare in the southern states and in Arkansas and eastern 
Texas is represented by only a few small shrubs. The Intricatae, 
composed mostly of small shrubs, has its greatest number of species 
in Pennsylvania and adjacent states, but is extremely rare in the Miss- 
issippi valley and unknown westward. The Molles Group, which contains 
the largest number of species which become trees of considerable size, 
is common in the northeast, almost unknown in the southeastern part of 
the country, and most abundant in Missouri, Arkansas and Texas to the 
valley of the San Antonio River and the Edwards Plateau. Descrip- 
tions and figures of twenty-five species of this Group are included in the 
new edition of Sargent’s Manual of the Trees of North America, and 
there are already indications that the number can be enlarged. Trees 
of this Group are the earliest of the American Hawthorns to bloom in 
the Arboretum, and three of them are now covered with open flowers. 
These three species are Crataegus arnoldiana, C. arkansana and C. 
mollis. They are all large and handsome trees, and have some his- 
torical interest for students of American Hawthorns, for it was these 
plants which first attracted attention at the Arboretum to differences 
in their flowers in the number of stamens and in the color of anthers, 
which first led to the critical study of Crataegus which has been going 
on here ever since and which among other things has led to the sow- 
ing of 4269 different lots of Crataegus seeds. 
Crataegus arnoldiana was found growing as a large rather mis- 
shapen shrub in the dense shade of large trees on the bank opposite 
the southern end of the Meadow Road. It has only been found outside 
of the Arboretum in the valley of the Mystic River at West Medford, 
Massachusetts, where a number of years ago there were several trees, 
and near Lyme, Connecticut. C. amioldiana has taken kindly to culti- 
vation and there are now a number of large and shapely specimens 
growing in the Arboretum. The largest of them are the two trees on 
the left hand side of the Valley Road close to the Centre Street en- 
trance, and there are other good specimens on the left hand side of 
the Valley Road in front of the White Oak Collection and in the old 
Crataegus Collection between the Shrub Collection and the Arborway 
boundary. The flowers of C. arnoldiana are about three-quarters of 
an inch in diameter, and are arranged in broad, many-flowered clusters. 
Like those of most of the eastern species of this group, they have ten 
stamens and yellow anthers. The fruit is bright crimson, subglobose, 
slightly hairy at the ends and about three-quarters of an inch in length. 
It begins to ripen the middle of August and falls early in September. 
The early ripening fruit of no other Hawthorn is so conspicuous. 
