208 
THE NATIONAL NURSERYMAN 
TIk'ic is no l)ell(M‘ or liardu'r |)laiit for lar^o sliriibl)erios 
or I ho l)or(l('rs of woods, and iniioli of tho early June 
hi'anlv of the Arl)or('tinn is duo to its "onoral use hero. It 
is OIK' of tin' tlii'oo Ainorioan arliorosoont spooios, the 
otlu'rs Ix'in" V. yrunifoUnin and V. rufuluhun. This last 
is a southorn jilant distin^uishod by its thick and shining 
loaves and by tho thick red-brown, felt-like eovering of 
the inl('r-buds and leaf-stalks. V. rufiduliun is still 
rare in eultivation but fortunately it is hardy in the Ar¬ 
boretum. Young ])lauts are now in flower in the Vibur¬ 
num (li-oup on the Bussey Hill Koad. 
On the right-band side of the Bussey Hill Bead, op¬ 
posite the Lilacs, a large mass of Viburnum ]>ubcsrens 
completely covered with small clusters of white flowers 
is now one of the most conspicuous objects in the Arbor¬ 
etum. This shrub grows from western New York west¬ 
ward and southward, and, although hardly known in 
gardens, is a first-rate garden ])lant. The eastern Amer¬ 
ican species with bright blue fruits, V. dentalum, V. ven- 
osuin, and V. Canbi/i, will flower later in the order in 
which they are mentioned here. They are common 
wild plants in the regions they inhabit and are all greatly 
inijiroved by good cultivation. They have been freely 
used in different ])arts of the Arboretum and their value 
for the decoration of American parks is at last beginning 
to be a|)preciatcd. 
The Arrow\\ood, Viburnum acerifolium, will soon 
be in flower. This inhabitant of northern forests is a 
small, shade-enduring shrub with neat foliage, small 
flower-heads and lilack fruit. It can be seen in large 
masses on the right-hand side of Bussey Hill Road where 
in going up the hill it is the last of the small collection of 
Viburnums planted in the grass border between the drive 
and walk. Viburnum affine, considered a variety of V. 
])ubcscens, a rare plant from southern Missouri, is now 
flowering in the Viburnum Group where in the next two 
weeks flowers may be seen of the still rarer V. molle 
from the southern states. Persons interested in the cul¬ 
tivation of shrubs should study carefully at different sea¬ 
sons of the year the Viburnums which have been as¬ 
sembled in the Arboretum. 
Enkianthus is an eastern Asiatic and Himalayan 
genus, with drooping clusters of small, bell-shaped flow¬ 
ers, and dry capsular fruits, and is related to Andromeda. 
Three Japanese species are well established in the Arbor¬ 
etum and can be seen in the Shrub Collection and in a 
large grouj) on the right-hand side of Azalea Path. The 
handsomest of the three sjiecies, E. campanulatus, is a 
tall shrub with slender erect stems and branches, and 
light yellow or rose-colored flowers. It is found in 
every Japanese garden where it is valued for the bright 
scarlet color the leaves assume in autumn, and where it 
is often cut into balls and other fantastic shapes. This 
Enkianthus is a garden plant here of real value. The 
other sjiecies, E. Jujionicus and E. subsessilis, are smaller 
])lants with smaller yellow flowers and are less valuable 
ornaments of the garden. 
Some of the most valuable shrubs now found in gar¬ 
dens are natural hybrids of related sjiecies or have been 
l»roduced by skilful hybridizeTS. One of the most beau¬ 
tiful of Lilacs, Syringa ebinensis, is a natural 
hybrid \\hicb appeared one bund red years ago in 
the Botanic Garden at Bouen. Several of the 
most attractive Honeysuckles are hybrids, and in re¬ 
cent years the crossing of different s])ecies in several gen¬ 
era has jiroduced new races of garden jilants which have 
vigor, hardiness and beauty not ])ossessed by their par¬ 
ents. A good example of the value of such hybrids is 
found in Deutzia Lemoinei, obtained by a Erench nur¬ 
seryman by crossing the Japanese D. (jracilis with D. par- 
viflora of northern China, and now in flower in the 
Shrub Collection. Although it resembles D. gracilis in 
habit, it grows into a taller and broader shrub; the flow¬ 
ers are larger and it is much hardier. It is certainly one 
of the best garden plants of recent introduction. The 
systematic crossing of sbrubss with the object of creat¬ 
ing new forms, except perhajis in the case of Boses, is a 
comparatively new industry, but it has already j)roduced 
startling results in such genera as Magnolia, Deutzia, 
Philadelplius, Ceanothus, Bhododendron, and Diervilla; 
and with the great number of new shrubs discovered in 
recent years in eastern Asia and eastern North Ameiica 
at his disposal the hybridizer will now have new and 
abundant op})ortunity to show his j udgment and skill in 
producing new races of iilants. Hybrid trees are nat¬ 
urally less common than hybrid shrubs and, excejit in the 
case of fruit trees, comparatively few attempts to cross 
different species of trees have been made. Trees wbich 
are believed to be natural hybrids, however, are not rare. 
There are several American Oaks which are jirobably hy¬ 
brids and these, so far as they have been tested in the Ar¬ 
boretum, grow more rapidly than their sujiposed parents. 
For example Ulmus vegeta, which is believed to be a hy¬ 
brid between two Euro})ean species, grows more rapidly 
than any other Elm-tree, and the so-called Carolina Pop¬ 
lar, which is not an American tree but probably a hybrid 
between the American Cottonwood and the European 
Black Poplar, outgrows, at least while young, all other 
Poplar trees. 
Several of the Bbododendrons in the collection at the 
base of Hemlock Hill arc in flower and the flower-buds 
of many others are fast opening. The end of this week 
and the beginning of next week will probably be the best 
time to visit this collection which is most easily reached 
from the South Street entrance where automobiles should 
be left. 
This is one of the most interesting times of the year 
to visit the Pinetum, for many conifers are now in their 
