280 
THE NATIONAL NURSERYMAN 
Notes from the Arnold Arboretum 
Tree Lilacs. This name is often given to three large- 
growing Lilacs of northeastern Asia which are now in 
flower and are conspicuous objects in the Arboretum. 
These plants all have white flowers in large clusters, and 
differ from other Lilacs in the shape of their flowers. In 
all other Lilacs the tube of the corolla is much longer 
than the calyx and longer than the stamens which are 
enclosed by it, while in the Tree Lilacs the tube of the 
corolla is not much longer than the calyx and shorter 
than the stamens which are therefore seen when the 
flowers open. On account of this difference in their 
flowers the Tree Lilacs have been thought by some botan¬ 
ists to belong to a different genus to which the name 
Ligustrina was given, and this is now the name of the 
section of the genus Syringa in which they are placed. 
The three species are much alike and only differ in the 
shape of the leaves, in the size of the flower-clusters and 
in the time of flowering. They lose their leaves early in 
the autumn without any change of color, and in this early 
shedding of their leaves is found their only drawback as 
garden plants for they are all hardy, grow rapidly, are 
good in habit and bloom freely, although the flowers of 
one of the species, Syringa japonica, are usually pro¬ 
duced more abundantly in alternate years. The first of 
these plants to bloom, S. amurensis , is a native of eastern 
Siberia and northern China, and is a small, bushy, rather 
flat-topped tree which in cultivation rarely exceeds 
twenty feet in height. The leaves are thick, dark green, 
long-pointed, from three to four inches long and from two 
and a half to three inches wide, and the spreading and 
slightly drooping flower-clusters are usually from twelve 
to fourteen inches long and broad. This plant was first 
raised in this country before 1870 in the Harvard Botanic 
Garden from seeds received from the Botanic Garden at 
St, Petersburg. It appears to be less commonly cul¬ 
tivated than the other Tree Lilacs. Judging by the cli¬ 
mate of the region where it grows naturally, it will 
probably prove one of the best shrubs or small trees for 
the northern interior region of Canada and for the north¬ 
ern states of the Mississippi valley. S. pekinensis is 
usually the next of the three Tree Lilacs to bloom, al¬ 
though this year it is beginning to flower rather later 
than S. japonica. It is a native of northern China and is 
a shrub rather than a tree, although it sometimes grows 
in this country thirty feet high, with numerous stout, 
spreading stems distinctly drooping at the ends and cov¬ 
ered with light yellowish brown bark separating into thin 
layers like that of some of the Birch-trees. The leaves 
are narrower than those of the other species, long-pointed, 
drooping on long stalks, and usually about three inches 
long and from half an inch to an inch wide. The flower- 
clusters, which are produced every year in immense num¬ 
bers, are smaller than those of the other Tree Lilacs and 
are flat, very unsymmetrical, partly drooping and about 
five or six inches long and broad. This fine plant has 
been growing in the Arboretum since 1883 when it was 
raised from seeds sent here from Peking by the late Dr. 
Bretschneider. S. pekinensis has been somewhat dis¬ 
tributed by American nurserymen and there are now 
large specimens in several Massachusetts gardens. The 
last of the three Tree Lilacs, S. japonica, is a native of 
the forests of northern Japan and a tree sometimes forty 
feet high with a tall stem sometimes a foot or more in 
diameter and covered with lustrous reddish brown bark 
like that of a cherry-tree, and comparatively small, 
spreading and ascending branches which form a rather 
narrow round-topped head. The leaves are dark green, 
lustrous, four or five inches long and about two and a 
half inches wide, and the flower-clusters, which are erect 
and more symmetrical than those of the other Tree Lilacs, 
are from twelve to eighteen inches long and from twelve 
to fourteen inches wide. This tree was first cultivated 
in the Arboretum from seeds sent here from Sapporo in 
Hokkaido in 1876 by Mr. W. S. Clark, the first president 
of the Agricultural College at Sapporo. The seedlings 
grow rapidly and in 1886 were fifteen or sixteen feet 
high. The Tree Lilacs are growing on the bank on the 
left-hand side of the Bussey Hill Boad in the Lilac Collec¬ 
tion, and one of the original seedlings of S. japonica 
which was planted in what was once a nursery can be 
seen on the left-hand side of the Forest Hills Road in 
front of the Crabapple Collection. This is the year for 
the abundant bloom of the Japanese species and the 
plants are covered with flower-clusters. 
Salvia officinalis. This little aromatic shrub is now 
in bloom in the Shrub Collection. The flowers are 
bright purple, showy, about three-quarters of an inch 
long, and are arranged in erect, terminal, compound 
racemes six inches in length. This plant is a native of 
southern Europe and has been cultivated in Europe for 
centuries for medicinal and culinary purposes, and for¬ 
merly was much used in making “sage tea.” Although 
rarely seen outside of the kitchen garden, it is well worth 
a place as a flowering plant in a collection of dwarf 
shrubs. 
Thymus Serphyllum. This is another fragrant plant 
of the same family as the Salvia, and is growing near it 
in the Shrub Collection where it forms a broad mat of 
light green leaves only a few inches high. In a few days 
this will be covered with innumerable small lilac-colored 
flowers. The “Mother of Thyme,” as this plant is some¬ 
times called, is an old inhabitant of gardens and is a use¬ 
ful rock garden plant. The fragrant leaves are some¬ 
times used like those of the common Thyme in cooking. 
Philadelphus purpurascens. This Chinese species is 
now covered with flowers. It is a large, vigorous shrub 
with long arching branches from which numerous 
branchlets spread at broad angles and are from four to 
six inches long; on these are borne on drooping stems the 
flowers which have a strong pungent and delightful odor, 
and are about an inch and a half in diameter with a light 
purple calyx and pure white petals which do not spread 
like those of many of the species but form a bell-shaped 
corolla. This is one of the most distinct and beautiful 
of all the Old World species, and one of Wilson’s impor- 
