51 
tree is readily distinguished from Tilia glabra by the short, firmly 
attached grey hairs which cover the under surface of the leaves during 
the season. This is a smaller tree than Tilia glabra rarely growing to 
the height of 75 feet. In Canada it has been found as yet only in the 
neighborhood of Montreal; it ranges to the coast of southern New 
England and New York, through the Middle States and along the 
Appalachian Mountains to those of North Carolina and Tennessee and 
from western New York to northern Wisconsin. This tree is now well 
established in the Arboretum where it has grown rapidly and is now 
well covered with flowers which open a week or ten days before those 
of T. glabra. The leaves of this tree have not been attacked here by 
red spiders. Two other American Lindens are established in the Ar^ 
boretum, Tilia heterophylla var. Michauxii and T. monticola. The 
lower surface of the leaves of these trees is covered during the season 
with silvery white felt. The handsomer of these trees, Tilia monticola, 
grows naturally only on the Appalachian Mountains at altitudes between 
2000 and 3000 feet and from southwestern Virginia to eastern Tennessee 
and western North Carolina, This Linden is always a conspicuous object 
for the leaves which are very oblique at the base droop on long slen¬ 
der stalks and are oblong and larger than those of the other American 
Lindens. This promises to be an excellent tree for more general culti¬ 
vation in northern parks and gardens. The other hardy species, T. heter¬ 
ophylla var. Michauxii, has grown more slowly in the Arboretum than 
T. monticola and is less distinct and beautiful. These two species and 
T. neglecta are growing side by side and close to the grass path in the 
rear of the Linden collection and can be easily compared. The Linden 
collection now contains some thirty species and hybrids and forms one 
of the most satisfactory and interesting groups of trees in the Arbor¬ 
etum. It is arranged in the meadow on the right hand side of the 
Meadow Road. 
The last Azaleas. As the yellow or flame colored flowers of Rhodo¬ 
dendron {Azalea) calendulaceum wither those of another Appalachian 
species R. (Azalea) arborescens begin to open. The flowers are white 
with bright red stamens and style and deliciously fragrant and do not 
open until after the leaves have grown nearly to their full size. The 
home of this plant is on the Appalachian Mountains on which it is found 
from western Pennsylvania to northern Georgia, in the neighborhood 
of streams in the rich soil of sheltered valleys growing to the height 
of from fifteen to twenty feet; and on the Carolina Mountains is 
often not more than three or four feet tall forming at altitudes of about 
5,000 feet above the sea, great thickets often many acres in extent. 
Recent studies of this plant show that its value as a garden plant is 
not generally understood and appreciated. The flowers vary to an un¬ 
usual degree in size and in the length and diameter of the corolla-tube 
and although the corolla is usually pure white a form is now known in 
which the corolla is suffused with rose; in another it is more or less 
striped with rose; in another form the corolla is tinged more or less 
deeply with yellow, and in another it is marked by a yellow blotch. 
These forms are all worth places in a collection of Azaleas, and it is 
possible that if seedlings were raised from them other and perhaps more 
