44 
twelve or fifteen feet high, with leaves dark green and very lustrous 
above and pale below, and with an odor when dry of newly mown 
grass. Sent to Europe more than a century ago it was soon lost from 
gardens until its reintroduction by the Arboretum in 1880. There is 
a mass of this Azalea on the right-hand side of the Valley Road in 
front of the Hickories. 
Rhododendron viscosum. This is the last of the Azaleas to bloom 
and is just beginning to open its flowers. It is an inhabitant of 
swamps in the eastern part of the country and is known as the Clammy 
Azalea or more generally perhaps as the Swamp Honeysuckle. As a 
garden plant it is chiefly valuable for the delightful fragrance of the 
pure white, long-tubed, clammy viscid flowers and for their lateness. 
Masses of this plant can be seen in front of the native woods on both 
sides of the Meadow Road. For more than two months Azaleas have 
now been in flower in the Arboretum, and during this period no other 
group of plants has given it more of beauty and interest. 
Rhododendron maximum. This native species is the last of the Rho- 
dodendrons with evergreen leaves to flower. It is one of the hardiest 
of all Rhododendrons in this climate, and no other species which can 
be successfully grown here has such large and handsome leaves. The 
flowers are white more or less tinged with pink, and are borne in 
rather small compact heads. They are handsome in their delicate col- 
ors, but are overtopped and a good deal hidden by the young branch- 
lets which, unlike those of R. catawbiense and of most other species, 
make their annual growth before the flowers open. The plants of this 
Rhododendron in the group at the base of Hemlock Hill, near the South 
Street entrance, are now in flower. 
Crataegus cordata. This is the last of the Hawthorns to bloom and 
is now in full flower. It is the so-called Washington Thorn and a native 
of the southern Appalachian foothills and of the region westward to 
Missouri. It is a tree sometimes thirty feet high with erect branches, 
small, nearly triangular, shining leaves which turn bright scarlet in 
the autumn, small, dull white flowers in small compact clusters, and 
small fruit which remains on the branches with little loss of color 
until late spring. The late flowers, the brilliancj^ of the autumn foli- 
age, and the abundance and brightness of the fruit during the wunter 
months make this one of the most desirable of the American Hawthorns 
as a garden plant. 
Viburnum Canbyi. This is the last of the Viburnums to bloom in 
the Arboretum where its flowers are just opening. It is a native of 
eastern Pennsylvania and of Delaware, and has recently been found in 
Indiana; it is the largest and handsomest of the blue-fruited American 
species of which V. dentatum is the best known. It is a plant which 
is improved by cultivation, and there are great round-topped specimens 
in the Arboretum twelve or fifteen feet high and broad, and splendid 
objects at all seasons. Such plants can be seen on the right-hand side 
of the entrance to the Administration Building and on the Meadow 
Road. The earliest Viburnum, V. alnifolium, flowered here the first 
of May, and from that day to this Viburnums have been flowering'in 
the Arboretum. 
