59 
At its best Sorbus americana is a tree twenty or thirty feet tall, but 
more often and here in the Arboretum it is a large shrub with spread- 
ing stems. The leaves are composed of numerous slender pointed 
leaflets; the small flowers are creamy white and produced in small 
crowded clusters which do not appear until the leaves are fully grown; 
in the autumn these turn dull orange-red some time before falling, 
but the great beauty of the tree is found in its great clusters of small 
bright orange-red fruits which by their weight become semi-pendent. 
The variety decora is a larger tree with broader leaflets; the flowers 
are nearly twice as large, and the fruit which is larger and there- 
fore more showy, is of the same color. This variety grows only along 
the northern border of the eastern and middle states and northward, 
and is perhaps the handsomest of all Mountain Ashes. Rarely seen in 
Massachusetts gardens it is often the chief ornament in those of the 
more northern parts of the country. There is a group of these Moun- 
tain Ashes on the right-hand side of the path leading from the Forest 
Hills entrance into the Shrub Collection. 
Prunus hortulana. This is the handsomest of the American Plums 
and one of the handsomest of the small trees of eastern North Amer- 
ica where it grows on rich bottom-lands from southern Illinois to 
southern Missouri. This is a tree sometimes twenty or thirty feet 
high, with a trunk covered with dark scaly bark, and stout, wide- 
spreading branches which form on the trees growing in the Arboretum 
a dense, round-topped and shapely head. The flowers, which are pro- 
duced in few-flowered clusters, are sometimes an inch in diameter and 
open when the leaves are less than half grown. When the trees are 
in bloom their appearance is not unlike that of several other Plum 
trees; and the great beauty of this tree is in its habit, in the long 
pointed, comparatively narrow and very shiny leaves which are now 
turning a deep bronze-red color. The fruit, too, which looks like a 
bright red cherry, is an inch in diameter and droops gracefully on 
slender stalks. It is beautiful although the flesh is hard and austere, 
and it is not as a fruit tree but as an ornamental tree that this Plum 
deserves a place in parks and gardens in which small trees are valued. 
Two specimens can be seen in the Plum Collection on the right-hand 
side of the grass walk leading into the Shrub Collection from the 
Meadow Road. 
Magnolias. The leaves of the Asiatic Magnolias fall late in the au- 
tumn without much change of color, and those of some of the Ameri- 
can species, notably M. acuminata, the so-called Cucumber-tree, M. 
tripetala, the Umbrella-tree, M. Fraseri, the Mountain Magnolia, and 
the great-leaved M. macrophylla, all turn to shades of yellow and 
brown, which make these trees so conspicuous at this season of the year. 
The leaves of the yellow-flowered M. cordata are still as green as they 
were at midsummer. Later they also will turn yellow or brown, but 
the leaves of the Swamp Bay, M. glauca, which are still as beau- 
tiful as they have been for the last six months, will fall' gradually 
here late in November or early in December without any change of 
color. Further south they remain on the branches usually until spring. 
