55 
base of Hemlock Hill in the rear of the Laurel plantation and is 
spreading rapidly there over a considerable area by shoots from under¬ 
ground stems. The Asiatic tree Aralia resembles in general appearance 
the American Hercules' Club, but is distinct from that tree in the ab¬ 
sence of stalks to the leaflets. There are a number of geographical 
forms of this tree; the one which is most commonly cultivated in this 
country is a native of Manchuria and eastern Siberia (var. mandshurica) 
which is sometimes found in commercial nurseries under the name of 
Dimorphanthus mandshuricus. The Japanese form (var. glabrescens) 
is chiefly distinguished from it by the pale color of the under surface of 
the leaflets; it is less hardy than the Manchurian form and is not often 
seen in this country. 
Oxydendrum arboreum, or as it is often called the Sorrel-tree or the 
Sour Wood, is with the exception of the Hercules’ Club the only North 
American tree hardy in the Arboretum which does not begin to flower 
before the middle of July. It is a native of the southern Appalachian 
mountain forests and the only tree of the Heath Family which can be 
grown in this climate, with the exception of the Laurel {Kalmia lati- 
folia) and the Rose Bay {Rhododendron maximum) which are shrubs at 
the north and only exceptionally trees in a few favored valleys of the 
southern mountains. The Sorrel-tree in its native forests grows fifty 
or sixty feet high, but at the north as it begins to flower abundantly 
when only a few feet tall, it is not probable that in this climate it will 
ever attain a considerable size. It is well worth growing, for its bright 
green shining leaves which have a pleasant acidulous flavor and in 
autumn turn bright scarlet, for its white Andromeda-like flowers erect 
on the branches of spreading or slightly drooping terminal clusters, 
and for its pale fruits v/hich in the autumn are conspicuous among the 
brilliant leaves. There is a group of these plants among the Laurels 
at the northern base of Hemlock Hill which will flower at the end of 
July or early in August. 
Stewartia pseudo-camellia is another summer flowering tree. It was 
one of the early plants which come direct to the United States from 
Japan, and before 1870 was distributed from the Parsons Nursery at 
Flushing, Long Island. It produces in August its pure white, cup-shaped 
flowers, which resemble those of a single Camellia; the autumn color 
of the leaves is dark bronze purple, distinct from that of any other 
plant in the Arboretum and handsome and interesting; the smooth pale 
gray bark which separates in large pale plates adds, too, to the inter¬ 
est of this tree. There are two specimens on the upper side of Azalea 
Path. 
Evodias are handsome little trees which also flower here after mid¬ 
summer. They belong to the Rue family, and are widely distributed 
in eastern Asia and occur also in Australia and Madagascar. The spe¬ 
cies have pinnate leaves, white or pinkish unisexual flowers in small 
clusters terminal on the shoots of the year, and dry, capsular fruit. 
Like the Phellodendrons, to which Evodia is related, they are protected 
from the attacks of insects by the pungent aromatic oil with which the 
leaves abound. Evodia has been growing in the Arboretum since 1905 
when Professor Jack brought the seeds of E. Daniellii from Korea. 
