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Complimentary

NEW SERIES VOL IV

NO. I

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF

POPULAR INFORMATION

JAMAICA PLAIN. MASS. MAY 4. 1918

Effects of the Severe Winter. The winter of 1917-18 has been one
of the severest in New England of which there is any record. In
December when the ground was without a covering ^of snow the
thermometer did not rise here from above zero for nearly a week with
a minimum of 17° below. There was little snow at any time during
the winter, and the ground, which froze to a depth of from five to
seven feet, was not clear of frost until after the first of April. Abun-
dant rains late in the summer and in the early autumn, and the fact
that the cold has been continuous through the winter, without periods
of warm weather, which in this region often excite dangerous vegeta-
tive activity, have enabled many plants to survive the extreme cold
which under less favorable conditions would probably have destroyed
them. Still it seems safe to predict that any tree or shrub which has
lived here through the past winter will be able to resist successfully a
Massachusetts winter. The condition of the plants in the Arboretum
at this time is of general interest therefore as an indication of the
trees and shrubs of recent introduction which can be successfully grown
in this climate. It must, however, be remembered that local conditions,
that is conditions of soil, position, moisture and dryness influence the
hardiness of plants, and that a tree which succeeds in the Arboretum
might not be hardy in another garden in the same general region.

The injuries to the Arboretum collections caused by the winter have
not on the whole been as great as we had every reason to fear three
months ago. The Conifers which have been killed are the glaucous-
leaved Mt. Atlas Cedar {Cedrus atlantica glauca) which has been kept
alive here for several years in a protected position; young plants of

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the Spanish Fir {Abies Pinsapo) which has been killed before in the
Arboretum; Abies magnijica of the California Sierra Nevada; Abies
cephalonica var. appolinis from the mountains of Greece; Picea Sar-
gentiana, one of the new Spruces from western China, and nearly
every plant in a large collection of the short-leaved Pine of the eastern
United States {Pinus echinata). These Pines were raided at the Arbor-
etum twenty years ago from seeds gathered on Staten Island, New
York, the northern limit of the range of this tree, and appeared to be
perfectly hardy until this year. On several conifers the buds are un-
injured and are beginning to swell, although the leaves have been
more or less browned by the cold and will soon fall. Conifers injured
in this way will probably recover, although their growth for the year
will be necessarily checked. Among the trees with injured leaves and
uninjured buds are the Cedars of Lebanon from the Anti-Taurus in
Asia Minor which have been growing in the Arboretum for sixteen
years without protection, and which it was hoped would be able to
support the worst conditions New England winters could offer. Other
conifers with injured leaves are the Sugar Pine {Pinus Lambertiana)
from the Sierra Nevada of California, the Mexican White Pine {Pinus
Ayacahuite), the Chinese Hemlock {Tsuga chinensis) which has lost
most of its top, and Abies cephalonica from the islands of Greece.
One or two specimens of this tree will probably not recover. The
leaves of the California Incense Cedar {Libocedrus decurrens), of Abies
grandiSy of Abies amabalis and of the Hemlock of the northwest coast
{Tsuga heterophylla) are slightly injured. The native White Cedar
{Chamaecyparis thyoides) is badly hurt and some of the plants will
probably die. The Red Spruce {Picea rubra) from northern New Eng-
land has suffered badly, as have the plants of the upright form of
Juniperus communis from central Massachusetts. The leaves of Abies
amabilis, too, from the Cascade Mountains of Oregon are slightly
browned, as are those of several plants of the Japanese Abies sacha-
linense. On a few of the plants of the Chinese White Pine {Pinus
Armandi), of the Japanese Pinus densiflora and P. Thunbergii, and of the
Chinese Pinus sinensis var. yunnanensis and var. denudata the leaves
are also brown. There is no reason, however, to doubt that these will
all recover. It is interesting that, with the exception of four exotic
conifers, three of which have been kept alive in the Arboretum with
much difficulty and have now perished, the most serious damage of the
winter to conifers has been to four native species, Picea rubra, Pinus
echinata, Chamaecyparis thyoides and Juniperus communis. All the
new Spruces and Firs from western China, with the exception of Picea
Sargentiana, are uninjured, as are practically all the Chinese Pines.
Uninjured, too, are the Carolina Hemlock {Tsuga caroliniana) the west-
ern Arbor Vitae {Thuya plicata), and the Spanish Pine {Pinus nigra
tenuifolia) which, judging by the climate of the regions where these
trees grow naturally might well have suffered from the cold of the
past winter.

Of the new trees with deciduous leaves introduced by the Arboretum
from China the following are uninjured: all the Oaks, Elms, Birches,
Nettle-trees, Beeches, many of the Cherries, the Pears and Apples,

3

Davidia, Eucommia, and Ehretia acuminata. As space permits reports
on the losses caused by the winter in other groups of plants will appear
in later issues of these bulletins.

Early-fiowering Shrubs. Fortunately frost has not injured this spring
the buds of many of the trees and shrubs which open their flowers in
April and several of these have been unusually fine this year and have
remained in good condition for a longer time than usual. After some
of the Willows the earliest shrubs in the Arboretum to bloom this
year were the Buffalo Berry {Shepherdia argentea) and the Leather-
wood {Dirca palustris). The latter began to bloom on the 7th of April,
nearly three weeks earlier than last year, and unfaded flowers are still
to be seen on this eastern American shrub. A large group of these
plants on the right-hand side of the Bussey Hill Road is one of the
interesting early spring features of the Arboretum. The flower-buds
of garden Peach-trees have been generally killed in Massachusetts by
the cold of the winter, but the wild Peach-tree of northern China
(Prunus Davidiana) opened its uninjured flower-buds in the Arboretum
on the 15th of April. This is an attractive small tree with erect
branches and lustrous red-brown bark. As a flowering tree in this
climate, however, it is hardly worth a place in gardens for the
flowers open so early that they are ruined by late frosts. The fruit is
small and of no value, but pomologists are interested in this tree as a
stock on which to work the common Peach-tree for it is hardy north
of the region where Peaches flourish.

Early-flowering Rhododendrons. The bright rose-colored flowers of
the Siberian and Mongolian Rhododendron dahuricum opened this year
as early as the 10th of April and remained in good condition until the
end of the month. It is a small shrub with dark green leaves which
in this climate remain on the branches until late in the winter, and it
would be a good garden plant here if the flowers were not so often
ruined by late frosts. There is a variety sempervirens with more per-
sistent leaves and darker-colored flowers which has bloomed this year
with the species on the upper side of Azalea Path. In the Rhododendron
Collection at the base of Hemlock Hill a group of a hybrid of
R. dahuricum with the Himalayan R. ciliatum, known as R. praecoXy
Early Gem, is now covered Vs^ith flowers. This is a perfectly hardy
plant but, unfortunately, blooms too early in this climate and the flow-
ers are generally injured by frost. More valuable here is the north
China R. mucronulatum which this year began to flower a little later
than R. dahuricum and is still covered with its pale rose-colored flowers.
It is a tall, hardy, deciduous-leaved shrub which has flowered
freely in the Arboretum every spring for the last twenty years. The
flowers open before the leaves appear and are not injured by spring
frosts. This year they have been in good condition for nearly three
weeks. In this climate this is the most valuable of the Rhododendrons
and Azaleas which bloom in April.

Early-flowering Magnolias. The flower-buds and the flowers of the
Japanese Magnolia steltata, M. Kobus and its variety borealiSy and of

4

the Chinese M. denudata, more often called M. conspicua, and its hy-
brids, have been uninjured by winter cold or April frost and are bloom-
ing well this year with the exception of M. Kobus and its variety
which, never very free with their flowers, are less prolific than usual
this year. The plants of the Japanese M. salicifolia, which has never
succeeded in the Arboretum by which it was first introduced into culti-
vation, appear to have been killed outright this winter.

Corylopsis. All the species of this genus of shrubs of the Witch
Hazel Family cultivated in the Arboretum have survived the winter
with little or no loss of wood, but the flower-buds of the Chinese C.
Veitchiana and C. Willmottae^ and of the Japanese C. paucijiora and
C. epicata have been killed by the cold, and the only species which
has flowered is C. Gotoana of the elevated region of central Japan.
This is evidently the hardiest of the plants of this genus, and as it
has now flowered in the Arboretum every spring for several years
there is good reason to hope that we have here an important shrub
for the decoration of northern gardens. The flowers are produced in
drooping spikes and open before the leaves appear, as in the other
species, and are of a delicate canary-yellow color and pleasantly fra-
grant. The best specimen in the Arboretum can be seen on the left-
hand side of Hickory Path near Centre Street.

Prinsepia sinensis is a tall Chinese shrub with stem and branches
armed with many spines, bright green leaves which unfold as early as
those of any other plant in the Arboretum, and bright yellow flowers
about two- thirds of an inch in diameter in few-flowered axillary clusters.
The large specimen on the right-hand side of Hickory Path near Centre
Street is now covered with flowers and nearly fully grown leaves.
There can be no question of the hardiness of this shrub or of its ability
to flower under any climatic conditions it may have to meet in Massa-
chusetts. It will perhaps be found that it will prove to be as good a
hedge plant as can be used in this part of the country. Unfortunately
the Arboretum plants have not yet produced more than an occasional
seed, and as Prinsepia is not easy to increase from cuttings it has
remained exceedingly rare.

Maddenia hypoleuca. This interesting shrub which flowered last
year in the Arboretum for the first time in America and was described
in the Bulletin of May 8th, came through the winter without injury on
the southern slope of Bussey Hill and was in full bloom this year on
the 18th of April. It is related to the Rum or Choke Cherries, but the
flowers are without petals and are not conspicuous.

Cherries and Plums. This is a good season for many of these
plants. Among the Cherries Prunus tomentosa and the single-flowered
form of P. triloba from northern China are already in bloom. The
trees of the Sargent Cherry [Prunus serrulata var. sachalinensis) have
never been more covered with their pink and rose-colored flowers, and
the Japanese Spring Cherry (P. subhirtella) which has been described
as the the most floriferous and perhaps the most delightful of the
Japanese Cherries, is just opening its countless flower-buds.

Complimentary

NEW SERIES VOL. IV

NO. 2

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF

POPULAR INFORMATION

JAMAICA PLAIN, MASS. MAY 9. 1918

Effects of the severe winter. Most of the Taxads which have been
grown successfully in the Arboretum have suffered from the cold of
the winter. All the forms of the Japanese Taxus cuspidata, however,
are now as green and fresh as they were in October. As the years
pass the confidence in the value of this plant increases and it has never
been as great as it is this spring. Among all the plants which Japan
has contributed to the gardens of the eastern United States no other
is so generally valuable. Fortunately American nurserymen are at last
beginning to realize that this Yew has some commercial value, and it
will soon be within the reach of everyone who has a garden or wants
to plant the best possible evergreen hedge for New England. The
form of this Yew (var. chinensis) introduced by Wilson from western
China is less hardy than the Japanese plant. In a collection of young
plants of the Chinese form, in as protected a position as could be
found in the Arboretum, some are slightly injured and others are dead.
It is not probable that this fine tree, therefore, will ever become es-
tablished in Massachusetts. On all the forms of the European Yew
{Taxus baccata) there are dead leaves and dead or injured branches.
All the plants of T. baccata erecta have been killed, and there are a
few dead branches even on T. baccata repandens, the plant with wide-
spreading, semiprostrate stems which has lived in this climate for sev-
eral years without injury and has been considerered here the hardiest
and most desirable of all the forms of the European Yew for New
England. Plants of the Canadian Yew (T. canadensis), the so-called
Ground Hemlock of northern woods, planted in the shade or in full
exposure to the sun, have been badly disfigured as the tips of most of
the branches and all the upper leaves have been killed. The leaves on
upper branches of the Japanese Torreya mucifera are dry and begin-

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ning to turn brown, but the buds appear to be uninjured and the plants
may recover. It has not suffered here before and for the last two or
three years has been producing fruit in the Arboretum. The California
Torreya (T. californica)^ which has been nursed along in a sheltered
position for years and has suffered more or less every winter, appears
to have at last entirely succumbed. Young plants in a sheltered posi-
tion of the Japanese Cephalotaxus drupacea are little injured but the
handsomer C. Fortunei from western China has suffered and it is
doubtful if this fine tree will live through many years in this climate.

Broad-leaved Evergreens. As it was natural to expect, the plants
of this class have been more injured by the winter than any others,
for with few exceptions they cannot be successfully grown in this
climate under even the most favorable conditions. Ilex opaca, which
has grown well in the Arboretum for many years where it has been
the only broad-leaved evergreen tree which has lived here, has suffered
seriously. Nearly all the leaves have been killed and some of the
plants appear to be dead. The large plants of the Japanese Ilex cre-
nata on Azalea Path, which were raised from seed at the Arboretum
twenty-five years ago, have been so badly injured that it is doubtful
if they can recover. The Inkberry {Ilex glabra), a common shrub in
the region of the coast from New Hampshire to Texas, has lost the
ends of many branches and most of its upper leaves. For more than
twenty years there have been splendid specimens of this beautiful
shrub in the Arboretum where it has never been injured before and
has been considered one of the best evergreen shrubs which can be
grown in this climate. Plants of an evergreen Holly {Ilex pedunculata),
introduced by Wilson from western China and planted on Hickory Path
near Centre Street, have, however, not been injured by the winter.
This is a handsome tree with long-stalked red fruits, and is distrib-
uted through Japan and western China. Judging by our experience
here with other evergreen Hollies, the chances that it will ever grow
to maturity are not very good. For the first time in the Arboretum
there are brown leaves and dead branches and flower-buds on some of
the Laurels {Kalmia latifolia). The damage is not serious but it is
interesting as showing how the hardiest native plants, even when
planted in exceptionally good positions, may be injured by a winter
like the last which has killed also the ends of the branches of such
common New England evergreen shrubs as the little Sheep Laurel
{Kalmia angustifolia) and the Leather Leaf {Chamaedaphne calyculata).
The leaves of Leucothoe Catesbaei are badly browned even on plants
in moist shady positions which this species prefers. A native of the
southern Appalachian forests, it has been considered one of the hardi-
est and most satisfactory broad-leaved evergreens which could be
planted in this climate. Leucothoe axillaris has also lost its leaves
but will probably recover. Pieris or Andromeda Jioribunda is unin-
jured and is now covered with flowers, and its condition confirms the
belief here that this is one of the hardiest, handsomest and most de-
sirable broad-leaved evergreen shrubs which can be grown in this part
of the country. Its Japanese relative, Pierus japonica, seems equally
hardy, but its larger and more beautiful flowers open earlier and are
often injured by spring frosts.

7

Evergreen Barberries. The four Cbinese evergreen Barberries, Ber~
beris Julianae, B. Sargentiana, B. verruculosa and B. Gagnepainii,
from which so much has been expected, have suffered seriously. B.
•Julianae and B. Sargentiana will probably not recover, and there is
little hope that much garden beauty will ever be obtained in this region
from evergreen Barberries, for all the Mahonias which have been
grown here are in unusually bad condition this spring, with the excep-
tion of the dwarf Makonia or Berberis r-epens from the Rocky Moun~
trins, and even this has lost many of its leaves. All the forms of the
European Box, although carefully protected, have suffered badly and
some have been killed. Even the Japanese Box (Buxus japonica),
which has been growing in an exposed position here for twenty years
without protection, will lose for the first time some of its leaves from
the ends of the branches. This handsome plant has suffered, however,
less than might have been expected, and if Box is to be planted in
eastern Massachusetts with the expectation that it will be a permanent
garden ornament it is this Japanese species which must be used. The
Chinese climbing Honeysuckle {Lonicera Henryi), which had proved
perfectly hardy until last winter and from which much was expected,
has lost all its leaves, but as its stems are still alive it may recover.
Teucrium chamaedrys and Salvia officinalis are nearly killed, and
Daphne cneorum, which has usually done well in the Arboretum, has
suffered seriously in the Shrub Collection and on Azalea Path. The
two evergreen Chinese Viburnums which have lived in the Arboretum
for several years. Viburnum rhytidophyllum and F, buddleifolium^
have lost all their leaves but may possibly recover.

Thanks probably to the abundant rains of the summer and autumn,
the Rhododendrons in the Arboretum have suffered less than they did
three years ago, although in some of the gardens near Boston the loss
of these plants has been more serious than ever before, whole planta-
tions which have been growing for thirty or forty years having been
destroyed. In the Arboretum the only species which has suffered is
R. micranthum, the only evergreen Chinese Rhododendron which has
ever lived long enough in the Arboretum to flower and which has now
lost many of its upper branches. There are dead branches on some of
the Catawbiense hybrids, and among them, in addition to a number of
hybrid seedlings sent to the Arboretum for trial by an English nursery,
the following have been killed: James Smith, Marshall Brooks, Mrs.
Thomas Agnew, Marquis of Waterford and Corner Waterer. One speci-
men of Mrs. C. S. Sargent, which has always been considered one of the
hardiest of all the Catawbiense hybrids, has been so injured that it will
have to be removed. Rhododendron azaleoides, or fragrans, one of the
hybrids between a Rhododendron and an Azalea, has also been killed.

Prunus incisa has bloomed in the Arboretum every spring for three
or four years but has never been as full of flowers or as beautiful as
it has been during the present week. This Cherry is a native of Japan
and is abundant on the eastern and southern slopes of Fuji-san and on
the Hakone Mountains. It is a large shrub or under favorable condi-
tions a small tree twenty-five or thirty feet high; the flowers appear
before the deeply cut leaves in drooping clusters; their calyx is bright

8

red; the petals are white or oecasionafTy tmg-ed with rose color, and the
anthers are bright yellow. The petals fall early but the calyx, which
gradually grows brighter in color, remains for some time on the young
fruit and is showy. Prunus incisa has been perfectly hardy here and
none of the flower-buds were injured by the cold of last winter. It
has the advantage, too, of flowering while still a small shrub. This
Cherry has remained rare in American and European gardens and ap-
pears to be still little known.

Plums. The flower-buds of few Plum-trees have been injured and
these trees promise to bloom unusually well this year. The first to
flower have been the Canadian Cherry {Prunus nigra) and the Chinese
Prunus salicina, the parent of the so-called Japanese Plums of pom-
ologists. These will soon be followed by Prunus alleghaniana, P. am-
ericana, P. Watsonii, P. Munsoniana, P. hortulana, P. domestica, and
several others. The Plums are planted with the Apricots, which are
also beginning to bloom, next the Cherries, near the junction of the
Meadow and Valley Roads.

A pink-flowered Pear-tree. Among the Pear-trees raised from the
seeds collected by Wilson in western China there are plants in the
Peter’s Hill Nursery and on the southern slope of Bussey Hill which
have bloomed this year for the first time and have been conspicuous
for their pale pink flowers which' open from rose-colored buds. The
flowers of all described species of Pyrus are pure white and this pink-
flowered form is an interesting addition to the list of trees with showy
flowers. It has been considered a variety of Pyrus Calleryana but
differs from that Pear-tree in its smoother red brown bark, in the
dense coat of tomentum which covers the branchlets, and in its earlier
pink flowers not more than three-cfuarters of an inch in diameter, and,,
it is possible that when the fruit is known, it may prove a new spe-
cies. The Chinese Pears have handsome foliage and beautiful flowers,
and they are all excellent hardy ornamental trees in the Arboretum.
They will bloom well this year, and the large specimen of P. ovoidea
near the Forest Hills entrance has been covered with flowers during
the week.

Some Maple Flowers. It is not often that the Sugar Maple {Acer
saccharum) in Greater Boston so completely covers itself as it has this
spring with its long gracefully drooping clusters of pale yellow flowers
which early in May make this tree, although now less conspicuous than
in the autumn, a charming feature 'of the northern forest. A true lover
of the country, life in cities and their suburbs has little attraction for
the Sugar Maple. It needs the free and pure air of the forest and of
the country roadside, and finds its greatest happiness on the low hills
of northern New England and Michigan, or in the rich protected val-
leys of the Appalachian Mountains. In such positions no Maple tree
surpasses it in size and beauty, and few trees equal it in the splendor
of the coloring of its autumn foliage. The large, cup-shaped bright
red flowers of one of the forms of the Japanese Acer diabolicum (var.
pupurascens) have been very beautiful this week, and as a spring-flow-
ering tree this small Maple well deserves more general cultivation.
The leaves, too, are large and handsome. There are three plants in
the Maple Collection, and a number of others in the mixed plantations
near the top of Peter’s Hill.

Complimentary

NEW SERIES VOL. IV

NO. 3

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF

POPULAR INFORMATION

JAMAICA PLAIN, MASS. MAY 11, 1918

Effects of the severe winter. Injuries to plants with deciduous
leaves have fortunately been less serious than to broad-leaved Ever-
greens. All Azaleas are unhurt in branch and bud, with the exception
of some of the flower-buds of Rhododendron {Azalea) Kaempheri, and
promise to bloom exceptionally well. The ability of some of the hand-
somest of the eastern North America and the eastern Asiatic Azaleas
to bear uninjured the cold of a winter like the last teaches an impor-
tant lesson; and it is well to repeat what has been so often said in
these Bulletins, that in these Azalea species, but not in their hybrids
which are usually short-lived and not always hardy, are found some of
the most beautiful of the shrubs which can be grown in this part of
the country, and that for the eastern United States they are more
satisfactory than any evergreen Rhododendrons. All the new Chinese
Cotoneasters have come through the winter without injury with the
exception of the variety elegans of C. Dielsiana, the varieties rugosa
and Jioccosa of C. salicifolia some plants of C. horizontalis and its vari-
ety perpusilla which have lost the ends of the branches. The fact that
most of these Cotoneasters have been able to support without injury
the cold of last winter is important, for among them are some of the
most beautiful of the Chinese shrubs of recent introduction. The
Chinese Poplars are uninjured with the exception of P. lasiocarpa,
which has never done well in the Arboretum, and P. yunnanensis, which
has lost a good many branches. This tree has suffered here before and
will probably not live long in eastern Massachusetts, although it has
grown well in the neighborhood of New York. The Chinese Butternut

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(Juglans cathayensis) is uninjured but some plants of J. regia raised
here from nuts gathered by Wilson in western China have lost their
buds, while others appear to be uninjured. Maples from western China,
on the whole, are not promising. Acer griseum, A. fulvescens and A.
pictum parvijiorum are still in good condition, but A. longifolia and A.
Henryii, which have suifered before, are now killed; and A. Davidii,
which once flourished in the Arboretum for several years, is again badly
injured. The new Cherry-trees from western China are all in good con-
dition with the exception of Prunus Conradinae. This tree has always
been delicate in the Cherry Collection, and the large plants on Peter’s
Hill have now all been killed. This handsome tree flowered two years
ago on the grounds of the United States Agricultural Station at Chico,
California. Neillia sinensis is uninjured and there appears no reason
why this beautiful shrub should not become a popular ornament in
northern gardens. The other Chinese species in the Arboretum, N. lon-
giracemosa and N. ajffinis, have been killed to the ground but the roots
are alive. The Chinese Spiraeas and Hydrangeas are uninjured, but
some of the Deutzias like D. longifolia and the varieties of D. discolor
have suffered as usual. Plants of all the Chinese Ash-trees are alive,
although the winter has been too severe for a plant each of Fraxinus
retusa var. Henryi and F. platypoda. Ligustrum Delavayanum has
been killed to the ground, as has Daphne genkwa. The injury to this
plant has been one of the serious results of the winter. The Chinese
Buddleias are usually killed to the ground here; as they flower on the
new shoots this is a matter of little importance, but the roots have
now been killed. Styrax americana of the southern states has been
killed and the Chinese S. dasyantha is so badly injured that it will not
recover. Unfortunately the only species probably of this beautiful
genus which can be successfully grown here are the Japanese S. japon-
ioa and S. obassia, and in this region these do not always grow as
well as they have in selected positions in the Arboretum.

Forsythias. For the second time in three years many flower-buds
have been killed on all the species and hybrids of this genus. On some
plants, especially those in low positions, all the buds were injured but
on high ground probably at least half the buds have opened. The hybrid
F. intermedia and its varieties have suffered the most, and the Chinese
F. suspensa and the Albanian F. europea have lost fewer buds than
the others.

All the Chinese Barberries with deciduous leaves are practically un-
hurt with the exception of Berberis Wilsonae, which has always been
rather tender here, its variety Stapfiana, which has always been con-
sidered a hardier plant, and B. triacanthophora. Few Chinese Honey-
suckles have suffered, but Lonicera pileata, which has flowered here
for several years, is killed to the ground, and the beautiful climbing
L. similis var. Delavayi has been killed.

Hamamelis. All the winter-flowering Witch Hazel plants are unin-
jured. Hamamelis vernalis was covered the middle of December with
flower-buds which promised to open earlier than usual but the extreme

11

cold later in the month destroyed them. The flower-buda of the Jap-
anese H. japonica and its variety were not hurt, but they did not open
until late in March or six weeks later than usual. The flower-buds of
the Chinese H. mollis were badly injured and only partly opened to-
ward the end of March.

Qaercus arkansana, from the neighborhood of Fulton in southern
Arkansas, has been killed, but the Nutmeg Hickory {Carya myristicifor-
mis) raised from nuts gathered within two miles of the place where
Q. arkansana grows is uninjured, as are Sapindus Drummondii from the
same general region and Malus angustifolia from Florida. More re-
markable is the hardiness of Carya texana, the so-called Bitter Pecan,
raised here from nuts gathered on the lower Brazos River in one of
the hottest parts of the Texas coast region where sugar is the prin-
cipal crop. On the other hand, more northern trees like the Liquid-
amber and the Persimmon {Diospyros virginiana) have lost many buds
and will certainly be disfigured. These are not Massachusetts trees
but they are natives of southern Connecticut and have been growing
for years in the Arboretum; and it might well have been supposed that
they would be hardier than trees from southern Arkansas, Florida and
the Texas coast. But the hardiness of a plant can only be determined
by experiments conducted through many years, as the effects of the
last winter have clearly shown. It is the office of the Arboretum to
make such long sustained experiments and to report on the results
obtained from them, and if nurserymen and other planters will study
this work of the Arboretum they will be saved many disappointments
and the loss of valuable time and unnecessary expenditures.

Asiatic Crabapples. Some of these trees are blooming very early
this year and many of them are carrying an unusually large crop of
flowers. Much attention has been paid at the Arboretum to this col-
lection because few plants have more beautiful flowers and fruits or
are better suited to this northern climate, and as the Apples of pom-
ologists have been obtained by crossing a few of the species of the
wild Crabs there is a chance that the future may disclose new and
perhaps improved races of Apples obtained by crossing some of the
recently introduced species with some of the varieties of orchard Apples.
A general interest in this collection is shown by the number of requests
for Crabapple grafting wood which are sent to the Arboretum from
Agricultural Experiment Stations and nurserymen from all the northern
parts of the country. The Arboretum collection is a large one and now
contains well established plants of all the wild Crabapples with the
exception of the Himalayan Malus sikkimensis which has not always
been quite hardy here. It also contains many hybrids both of Asiatic
and American species. The Asiatic species and several of the American
species, as well as many hybrids, are now large enough to flower and
produce fruit, and the collection affords an excellent opportunity for
study. The Crabapples are in two groups, the first on the left-hand side
of the Forest Hills Road, and the second at the eastern base of Peter’s
Hill where will be found the greatest number of species. The Japanese
and Chinese species can be considered hardy as they have not been
injured by the past winter, with the exception of Malus yunnanensis.

12

Some of the plants of this small tree are dead or badly hurt, but one
tree in the nursery at the top of Peter’s Hill is uninjured.

Malus cerasifera. The earliest of the Asiatic Crabs to bloom is be-
lieved to be a hybrid between Malus baccata and M. prunifolia, which
has generally been called M. cerasifera. It is one of the largest of
these trees, and in good soil and with abundant space it can form a
wide-branched, round-topped, shapely tree. The flowers are larger
than those of other Asiatic Crabapples, pure white and fragrant, and
the fruit is globose, rather dull red, and sometimes an eighth of an
inch in diameter.

Malus baccata var. mandshurica. Another desirable Crabapple as a
flowering tree is the variety mandshurica of M. baccata, a common
north China, Korean and Japanese plant. This has pure white flowers
only a little smaller than those of M. cerasifera and more fragrant
perhaps than those of any other Apple-tree. Last week a good speci-
men of this Crabapple in the Peter’s Hill Collection was covered with
flowers which perfumed the air for a long distance. Another still little
known species, Malus micromalus, has been unusually attractive with
its small pink flowers. This is a tree with erect branches which form
a narrow pyramidal head, and smooth pale bark. Its habit will make
it valuable in many gardens.

Korean Azaleas. On the upper side of Azalea Path two Korean
Azaleas, Rhododendron Schlippenbachii and R. poukhanense have been
covered with flowers during the past week. The former has large ob-
ovate leaves and white flowers more or less tinged with rose, and from
three to three and one half inches in diameter; the corolla is thin and
delicate in texture, and when fully exposed to the sun soon fades.
The flowers will probably last longer in partial shade. The plants
appear perfectly hardy in the most exposed position. This is a common
shrub on the grassy slopes above the cliffs on the Korean coast and
other parts of that country, but has remained little known in gardens,
although its flowers are perhaps the loveliest of all Asiatic Azalea
flowers. Rhododendron poukhanense has been covered again, as it has
been every spring for several years, with its clear rose-colored fragrant
flowers. This is one of the best of the Azaleas introduced by the
Arboretum into American gardens, and a hardy decorative plant of
first-rate importance.

An illustrated guide to the Arboretum containing a map showing the
position of the different groups of plants has been published. It will be
found useful to persons unfamiliar with the Arboretum. Copies of this
guide can be obtained at the Administration Building in the Arbor-
etum, from the Secretary of the Massachusetts Horticultural Society,
300 Massachusetts Avenue, Boston, from The Houghton, Mifflin Com-
pany, 4 Park Street, Boston, and at the office of the Harvard Alumni
Bulletin, 18 Plympton Street, Cambridge. Price, 30 cents.

Complimentary

NEW SERIES VOL. IV

NO. 4

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF

POPULAR INFORMATION

JAMAICA PLAIN. MASS. MAY 16. 1918

Effects of the Severe Winter. The condition of the new Chinese
Roses in the Shrub Collection is not as bad as might have been ex-
pected and will perhaps interest persons who are beginning to culti-
vate these plants. The yellow-flowered species, Rosa Hugonis, the
single and double-flowered forms of R. xanthina and R. Ecae from
Chinese Turkestan are uninjured. The last has been considered rather
a tender plant here. The least beautiful, perhaps, of yellow-flowered
Roses it has considerable geographical interest. The following are also
uninjured: R. davurica, R. sertata, R. Helenae, R. Sweginzowii, R.
banksiopsis, R. saturata, R. setipoda, R. bella, R. omeiensis, and R.
multiflora cathayensis. The stems of the following have been killed
to the ground or nearly to the ground, but the roots are probably
alive: R. oorymbulosa, R. Davidii, R. Prattii, R. filipes, R. Moyesii,
R. Moyesii rosea, R. Gentiliana, and R. multibracteata. R. Willmottae,
which grows well at Rochester, N. Y., but has always been tender in
the Arboretum, appears to be dead. Additions to the number of Chin-
ese Maples mentioned in the last Bulletin which have been killed are
Acer sinense and A. tetramerum. The latter flowered in the Arbore-
tum a year ago. Other Chinese plants which have been killed are
Stachyurus chinensis, Sophora viciifolia, Viburnum ovatifolium, Sta-
phylea holocarpa, Sorbus pallescens, Poliothyrsis sinensis, Fortunearia
sinensis, Sycopsis sinensis, Liquidambar formosana monticola, and
the Chinese form of Symplocos paniculata. The Sophora has been
growing in the Arboretum since 1906, and as it has for several years
flowered and produced great crops of seeds here it was believed to be
one of the hardiest as it is one of the most beautiful shrubs of recent

13

14

introduction. All the plants of Viburnum ovatifolium are killed, but
plants of the other Chinese Viburnums with deciduous leaves are alive
and in good condition. Staphylea holocarpa, which when in flower
Wilson considered one of the most beautiful of the Chinese trees,
has always been tender in the Arboretum and it is not probable that it
will ever flourish here.

Some interesting shrubs have been killed to the ground but will
probably recover; among them are the two Chinese Dipeltas, the
Chinese Rhus Potaninii, the Chinese Cornus paucinervis, and the Chin-
ese Salix Bockii. Osmaronia or Nuttallia cerasiformis from the Pacific
coast, the Rocky Mountain Ceanothus Wrightii, all the Bladder Sennas
{Colutea)y and the Japanese Benzoins ericium and B. obtusilohum; the
last, which for twenty-five years has been one of the rare and inter-
esting plants in the Arboretum, will probably not recover. The familiar
Exochorda racemosa or grandifiora has suffered badly, but the less
known and handsomer species from western China, E. Giraldii and E.
Giraldii Watsonii are uninjured and are now in flower. E. macranthu,
a hybrid between E. racemosa and E. Korolkowii is uninjured and is
also in bloom. Many of the forms of the Japanese Prunus Lannesiana
have suffered badly and several are dead. Among these are some of
the double-flowered Cherries which' are generally cultivated in Japan.

There are some serious losses among the Oaks. All the trees of the
Willow Oak (Q. Phellos) of the south are dead. The largest of them
here had been growing in the Arboretum since 1877 and had not been
injured before. The largest plant of Quercus georgiana is dead. This
is a rare tree from the Stone Mountain region of central Georgia, and
the plant that has now been killed had been uninjured in the Arbore-
tum for twenty-one years. Many large trees of the Shingle Oak {Quer-
cus imbricaria) are seriously injured, and plants of the southern Red
Oak {Quercus rubra or falcata) which have been growing here since
1889 are killed. Quercus heterophylla, which has been growing unin-
jured in the Arboretum since 1879, is also killed. This handsome and
interesting tree is the first hybrid Oak noticed in America and has
given rise to many discussions among dendrologists. All the plants of
the Turkey Oak {Quercus Cerris) are killed, and all the upper branches
of a large specimen of the form of the common English Oak with
pendulous branches (Q. Robur pendula) planted in 1899 are dead. Two
southern Nettle-trees, Celtis mississippiensis and C. georgiana, have also
been killed.

Early-flowering Lilacs. The earliest flowering Lilac here in other
years, Syringa affinis, is not blooming this year and there are not many
flowers on its variety Giraldii with pale rose-colored flowers. The
flower-buds of these Lilacs are perfectly hardy and the cold winter can-
not be charged with the absence of flowers on these north China plants.
They are tall shrubs of loose and rather ungainly habit, but the foliage
is good and the flowers are extremely fragrant. Another north China
Lilac, S. oblata, is blooming well this year although the flower-buds
are often injured by the cold of less severe winters. If this Lilac

15

always flowered as well as it has this spring it would be one of the
most valuable of the whole group for it blooms early, and the pale
lilac-colored flowers in short compact clusters are very fragrant. The
large broad leaves which are thick and leathery and are not disfigured
by mildew turn in the autumn to handsome shades of orange and red.
One of the first hybrid Lilacs was obtained by crossing this Chinese
species with the common Lilac (S. vulgaris). The plant obtained by
this cross is called S. hyacinthiflora. It is a large, compact, round-
topped shr lb with leaves resembling in shape those of its Chinese par-
ent and with small clusters of extremely fragrant, pale lilac-colored
double flowers. As a garden plant this Lilac is more interesting than
beautiful. Syringa pubescens is covered with clusters of opening
flower-buds. Attention cannot be too often called to this native of
northern China. It is a tall shrub with erect stems, small leaves and
short broad clusters of pale lilac-colored flowers remarkable for the
long tube of the corolla and for their pungent and delightful fragrance.
For this fragrance, if for no other reason, this Lilac should be found
in every northern garden; indeed some persons consider it the most
valuable of all Lilacs. Although S. pubescens was first raised at the
Arboretum thirty-six years ago, it is still rare in this country, for it
never produces seeds here and is not as easily propagated by cuttings
as other Lilacs. It is in bloom nearly four weeks earlier than it was
last year. Indeed all the Lilacs are early this year, and by the time
this Bulletin reaches its Boston readers many of the varieties of the
common Lilac will be in full bloom.

Early-flowering Hawthorns. The earliest Hawthorn this year to
bloom was Crataegus nigra from western Europe. This is a handsome
tree with pale bark and deeply lobed leaves. The flowers have twenty
stamens with anthers faintly tinged with pink and are arranged in
compact clusters; they are followed by handsome black shining fruits
which give greater value to this tree than the flowers which are less
beautiful than those of many American Hawthorns. There is a large
plant of Crataegus nigra in the old Hawthorn Collection at the end of
the Willow Collection. Several American Hawthorns of the Mollis
Group, distinguished by their large flowers, large leaves and large
scarlet fruit, have been in bloom during the past week. The most
conspicuous have been C. Arnoldiana^ C. mollis, C. arkansana and C.
submollis. These trees have never flowered more profusely. C. Ar-
noldiana, which was first found growing wild in the Arboretum, has
been especially handsome. The fruit of this tree begins to ripen late
in August or early in September and this makes C. Arnoldiana valuable
also for the decoration of the summer garden. The largest plants of
this tree in the Arboretum are on the left-hand side of the road near
the Centre Street entrance. There are a number of good trees in the
old Crataegus Collection and on the Valley Road in front of the White
Oaks. Large plants of the other early-flowering Mollis species can be
seen at the South Street entrance. In the Crataegus Collection on the
eastern slope of Peter’s Hill many plants are already in bloom and for
the next six weeks it will be possible to see in the Arboretum Hawthorn
flowers of many native and foreign species.

16

Early-flowering: Cotoneasters. Two of the handsomest Cotoneasters,
C. multiflora calocarpa and C. racemiflora soongorica, are in bloom
on the southern slope of Bussey Hill. They are tall broad shrubs with
white flowers in compact clusters standing up along the whole length
of the long, slender, graceful, arching branches. Handsome as these
plants are in May they are even handsomer in the autumn when their
large and abundant red fruits are ripe. These two shrubs, which
have now been well tested in the Arboretum, give every promise of
becoming important garden plants in the northern states.

Late-flowering Amelanchiers. The arborescent Shad Bushes, Ame-
lanchier canadensis, A. laevis and A. oblongifoLia, dropped their petals
nearly two weeks ago, but the flowers of some of the shrubby species
are still in good condition and attractive subjects for the spring gar-
den. Among the last of these to flower are the two Old World species,
A. vulgaris of Europe and A. asiatica of eastern Asia. Some of the
handsomest of the late-flowering American species are A. sanguinea,
A. stolonifera, A. florida and A. pumila. The Amelanchier Collection
is on the grass path on the left of the Meadow Road not far beyond
the Administration Building.

Malus Arnoldiana. In the last Bulletin attention was called to
the hybrid Crabapple, Malus cerifkra. This plant is probably one of
the parents of another hybrid which sprang up spontaneously in the
Arboretum many years ago and has been called M. Arnoldiana. The
other parent is probably M. floribunda, itself believed to be a hybrid
which originated in China. If this view of the origin of M. Arnoldiana
is correct, it is the offspring of two hybrids of different parentage and
a good illustration of what can be obtained by crossing and recrossing
the Crabapples. It is a low, broad, bushy tree with long arching up-
per branches which are raised well above the general head of the plant
and are wonderful objects when clothed from end to end with flowers
and the blue sky is seen between them. The flower-buds, like those
of M. floribunda are deep rose color and the petals after the flowers
open gradually turn from rose color to white. The flowers, however,
are as large as those of M. cerifera, or nearly twice as large as those
of M. floribunda, and the fruit which is red is intermediate in size
between those of the parents. The plant of the Arnold Crab in the
Forest Hills Road Group and several plants in the Peter’s Hill Group
have not before been more full of flowers or more beautiful.

Early-flowering Buckeyes. The first of these plants to flower this
year is the form of the Ohio Buckeye from northern Missouri with
leaves of seven instead of five leaflets {Aesculus glabra Buckleyi). The
flowers of this variety are brighter yellow and handsomer than those
of the common form of this tree, and the plants in the Arboretum
collection which are now covered with flowers are more beautiful than
ever before. The flowers of the typical form with leaves of five
leaflets open only a few days later than those of this north Missouri
tree. The largest specimen of the Ohio Buckeye in the Arboretum
is on the left-hand side of the South Street entrance. Another form
of this tree, var. leucodermis, from southern Missouri and northern
Arkansas has smoother bark and blooms later. In the Arboretum col-
lection the flower-buds are not more than half grown.

Complimentary

NEW SERIES VOL. IV

NO. 5

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF

POPULAR INFORMATION

JAMAICA PLAIN, MASS. MAY 21, 1918

Lilacs. Some of the best of the newer varieties of the common
Lilac {Syringa vulgaris) have been in bloom during the past week and
the following are worth the attention of persons who make Lilac
collections: Deuil d'Emile Galle, with pale pink double flowers; Wal-
deck Rousseau, with pink single flowers; L’Oncle Tom, with dark red-
purple single flowers; Grand Due Constantin, with light lilac-colored
flowers; Toussaint Louverture, with unusually long narrow clusters of
red-purple flowers. This is a tall growing plant with erect stems and
of not particularly good habit, but the long narrow clusters of flowers
are attractive. De Mirabel, with single very dark lilac-colored flowers
in long narrow clusters; Edmund Bossier, with dark rose-purple single
flowers in large broad clusters; Maurice de Vilmorin, with pale, lilac-
colored double flowers; President Loubet, with deep lilac single flowers;
Languis, with pale pink single flowers opening from dark rose-colored
buds; and Reamur, with large, single, rose-colored flowers in broad
clusters. An unusually large number of the varieties of the common
Lilac have flov/ered well this year and among the older varieties the
following have been unusually good: Congo, with large, dark red-purple,
single flowers; Macrostachya, with pale pink, single flowers in long
narrow clusters. Like Toussaint Louverture, this variety has erect
stems which do not make a handsome bush, and the flowers, too, begin
to open before the leaves appear. The flowers, however, are so deli-
cate in color that some persons consider this one of the handsomest
garden Lilacs. Other varieties which have been unusually good are
Marliensis pallida, with broad clusters of pale pink flowers; Furst
Lichtenstein, with single pink flowers; Condorcet, with double pale blue

17

18

flowers opening from dark rose-colored buds; Justi, with small pale
blue flowers; Ludwig Spath, with dark red-purple single flowers. This
last is very similar to Philemon and in these two plants are found
probably the handsomest Lilacs with dark red-purple flowers. Marie
Legraye, with single white flowers, is good as usual. Some of the
white-flowered Lilacs recently produced in France have larger indi-
vidual flowers, but little is known here yet of their value as garden
plants, and Marie Legraye must still be considered the best of the
thoroughly tested single white-flowered Lilacs.

Syringa chinensis. Unfortunately named for it is not Chinese but a
hybrid which appeared more than a century ago in the Botanic Garden
at Rouen, Syringa chinensis is also now in bloom. Obtained by cross-
ing the common Lilac with the Persian Lilac {S. persica), it has the
slender branches, the small leaves and the small flowers of the latter,
but its large size, the large flower clusters and the color of the flow-
ers show the influence of the other parent. Syringa chinensis is one
of the most valuable of all Lilacs; it is perfectly hardy, it grows rap-
idly to a large size, and it never fails to produce its long clusters of
reddish lilac flowers which cause the slender branches to droop grace-
fully. There is a variety with white flowers tinged with pink (var.
alha) and other varieties with slightly darker or lighter flowers than
those of the common form. This hybrid flowers a few days earlier
than the Persian Lilac. This is a broad rather low shrub with narrow
pointed leaves and small, fragrant, pale lilac-colored flowers in few-
flowered clusters which are crowded at the ends of the branches and
appear like one long inflorescence. There is a white-flowered form
(var. alba) and one with lobed leaves (var. laciniata). A native of
Afghanistan, the Persian Lilac was cultivated in India and Persia from
very early times and reached Europe three hundred years ago. A very
old inhabitant of American gardens, it is now not often cultivated in
this country. The earliest of the new Chinese Lilacs to bloom this
year, Syringa microphylla is in bloom. It is a plant with small leaves
and small, pale pink, fragrant, long-tubed flowers in small short clus-
ters. The flowers resemble those of S. puhescens, but it is a less val-
uable garden plant.

Bush Honeysuckles. Many of the Bush Honeysuckles are again cov-
ered with their fragrant flowers. No shrubs, not even the Lilacs, are
more valuable garden plants in regions of extreme cold. They are
very hardy; they flower freely every year, and many of the species
and hybrids are covered in early summer with scarlet, yellow or blue
fruit. To obtain the greatest beauty of these shrubs they must be
planted in good soil with sufficient space betw’een them for their free
growth. An example of well-grown Bush Honeysuckles can be seen on
the right-hand side of the Bussey Hill Road opposite the Lilacs where
there are several large plants. There is a large collection of smaller
plants in the Shrub Collection, and a supplementary collection along
the grass path in the rear of the Linden Collection on Meadow Road.
Attention is called again to Lonicera Morrowii, because the plant usu-
ally sold in American nurseries under that name is not L. Morrowii
but a hybrid of that species with the Tartarian Honeysuckle and of

19

little value for those who want a plant with the peculiar habit of L,
Morrotvii. This species is a native of northern Japan and eastern
Siberia, and one of the handsomest of the Bush Honeysuckles. It is
a comparatively low round-headed shrub with the lower branches which
cling close to the ground and spread over an area much broader than
the height of the plant. The leaves are gray-green and the flowers
are large, pale yellow and white; the fruit, which remains a long time
on the branches, is red and lustrous. The shrub was introduced into
the United States by the Arboretum many years ago and at one time
was largely planted in the Boston parks where there can still be seen
some large specimens. Attention is also called to the different forms
of the Tartarian Honeysuckle L. tatarica, with white, pink and rose-
colored flowers, L. minutiflora, L. muscaviensis, L. Xylosteum, L.
orientalis, L. chrysantha, one of the earliest of the group to bloom,
L. bella, L. notha and L. microphylla. This very attractive little
bush, a native of central Asia, is now in flower. The pale canary
yellow flowers are longer than the small pale blue leaves and stand
well up above them; the bright red, long-stalked fruit of this shrub is
also attractive.

Mountain Ashes. On the right-hand side of the path leading to the
Shrub Collection from the Forest Hills Gate are now in flower or
will soon be in flower, a number of these plants, including the two
of northeastern North America, Sorbus americana, and its variety
decora. These are large shrubs or small trees and less showy perhaps
when in flower than some of the Old World species; they surpass, how-
ever, all other plants of this genus in the brilliancy of their fruit, and
in the size of their fruit clusters. The autumn coloring of the leaves
of these plants, too, is beautiful. There is another collection of Moun-
tain Ashes, principally Asiatic, on the left-hand side of the Valley Road
near the group of Swamp White Oaks {Quercus bicolor) and several of
these plants are now in bloom. There is a good specimen of the
Japanese Sorbus alnifolia, one of the simple-leaved species, now in
flower on the right-hand side of the Forest Hills Road near the Wis-
taria trellis. This is a shapely, hardy tree which was raised at the
Arboretum from seed twenty-five years ago and is well worth a place
in Massachusetts gardens. All the species of Sorbus are liable to in-
jury from the San Jose scale, but this can be easily controlled by
spraying the trees late in March or in early April with a solution of
lime-sulphur or with scalyside.

Aesculus arguta. This little shrub, which is a native of eastern
Texas and Oklahoma, is blooming for the first time in the Arboretum
and probably for the first time in cultivation. Its relation is with the
Ohio Buckeye; it has leaves of seven or nine narrow, long-pointed,
pale leaflets, long, many-flowered clusters of pale yellow flowers and
fruit covered with prickles. This shrub is common near Dallas and in
Cherokee County, Texas, where it was first distinguished, and in
Oklahoma, it ranges further west than the other Buckeyes. The plants
in the Arboretum collection have been raised from seeds collected in
central Oklahoma. Some of the other little known southern Buckeyes
have escaped injury and will soon be in bloom. Among them are the

20

handsomest and most widely distributed red-flowered species, Aesculus
discolor var. mollis, when in flower one of the handsomest shrubs in
the southern states. Aesculus georgiana with large red and yellow
flowers in compact clusters, its variety pubescens and two hybrid
Buckeyes, Aesculus Bushii and A. Harbisonii. While these have al5
escaped injury the summer-flowering Aesculus parvifiora, which is an
old inhabitant of northern gardens and which has not before been in-
jured in the Arboretum, has lost many stems.

The earliest Roses. On May 17th the first flowers of the season on
the earliest Roses opened, Rosa Ecae and R. Hugonis. The former is
a native of central Asia and is a small, exceedingly spiny shrub with
small leaves and pale canary yellow flowers not more than an inch in
diameter. R. Hugonis is a large shrub with gracefully arching stems;
the flowers are about two and a half inches in diameter, with bright
clear yellow petals and are very fragrant. The plant in the Shrub
Collection is not quite as full of flowers as it was last year, but for
the next few days this Rose will be one of the most interesting and
beautiful plants in the Arboretum.

Rhododendron (Azalea) japonicum is in bloom on the lower side of
Azalea Path. This is one of the parents of the hybrid Azalea mollis
of gardens, and has the flame-colored flowers of some of the forms of
that plant.' R. japonicum, however, is a much more desirable plant
than any form of Azalea mollis which at best is only short-lived here.
Although discovered and first described many years ago, R. japonicum
has always been one of the least known in gardens of the hardy Aza-
leas. The large plants in the Arboretum were raised from seed brought
from Japan by Professor Sargent in 1892, but little attention has been
paid to them until recently as they were supposed to be Azalea mollis.
Now it is believed here that R. japonicum is the handsomest of all the
hardy Asiatic Azaleas and a garden plant of exceptional value. Al-
though the Arboretum plants are not blooming as freely as last year,
there are flowers enough on them to show their beauty.

Deutzia grandiflora flowered in the Arboretum for the first time
three years ago and has been again in bloom among the Chinese Shrubs
on Bussey Hill. It is a dwarf plant with flowers about three-quarters
of an inch in diameter, and usually solitary or occasionally in two- or
three-flowered clusters. It is a native of northern China and there is
reason to hope that it may in the hands of a skilful hybridizer be as
valuable as another north China species, Deutzia parvifiora, was in
producing a race of hardy garden Deutzias.

The flower-buds of the Flowering Dogwood {Cornus fiorida) are killed,
and visitors to the Arboretum will be deprived this year of the enjoy-
ment of the conspicuous flowers of this tree which is one of the most
interesting inhabitants of the forests of eastern North America.

Complimentary

NEW SERIES VOL. IV

NO. 6

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF

POPULAR INFORMATION

JAMAICA PLAIN, MASS. MAY 29, 1918

The early spring. The cold of last December exceeded the cold of
any' previous December in Massachusetts of which there is a record,
and now in this month there have been the hottest May days eastern
Massachusetts has known since a record of temperature has been kept.
April, too, was warm and dry, and even the early-flowering shrubs
bloomed earlier than usual. Lilac flowers, which last year did not open
in time for Decoration Day were fading this year by the 19th of May,
and Viburnum Lentago, which usually blooms here about the middle
of June was opening its flowers on the 20th of May and for the last
ten days has been one of the conspicuous plants in the Arboretum.
Many plants, especially Crabapples, Pears, Lilacs, Hawthorns, Honey-
suckles and Viburnums have not before flowered more profusely and
those which normally bloom a week or two apart have this spring
flowered simultaneously, with the result that during one or two weeks
more flowers have been open in the Arboretum than in any other weeks
in its history. The spring, however, has not been a satisfactory one,
so many plants have flowered together that visitors have been unable
to enjoy them all; and flowers forced by excessive heat to open before
their natural time have been short-lived. Plants crippled by the winter
have further suffered by the heat and drought of May which have
seriously interfered with the recovery of some plants.

Some early-flowering Rhododendrons. During the past week several
Rhododendrons have been in flower. One of the handsomest of these
plants, Boule de Neige, shows no effects of a hard winter. The leaves

21

22

are as green as they were in October and the flower-buds have not
been injured. It is a dwarf plant rarely growing to the height of three
feet but the branches are wide-spreading and form a broad, compact,
round-topped head. Little appears to be known of the history of this
plant; it is evidently a hybrid and R. caucasicum is no doubt one of
the parents. Judging by the leaves, R. catawhiense, or one of its hy-
brids, may be the other parent. The French name suggests that it
was raised in France as does the name of the raiser, Oudieu, given
in a recent English work on Rhododendrons. The Arboretum will be
glad of information about the origin and parentage of this plant.
Whatever these may have been Boule de Neige seems one of the har-
diest Rhododendrons which can be grown successfully in this climate.
Another dwarf Rhododendron, Mont Blanc, a variety or hybrid of R.
caucasicum, flowered a few days earlier than Boule de Neige. It is a
dwarfer plant and the flowers are rose color when they first open but
soon become pure white. This is a plant which has bloomed in the
Arboretum for several years and has never been injured. The history
of its parentage and origin are not recorded. A hybrid, R. caucasi-
cum, with rose-colored flowers, sold in nurseries as R. Jacksonii al-
though that name properly belongs to another hybrid, has lost a good
many leaves and some of the flower-buds. R. carolinianum is unin-
jured and has been flowering for the past ten days. The fact that it
has been able to come through the past winter without losing a leaf
or bud speaks well for the ability of this little southern plant to adapt
itself to the New England climate. The form usually cultivated has
pale rose-pink flowers, but the form with pure white flowers is the
more common in the mountain forests of the Carolinas which is the
home of this species. R. Smirnowii, uninjured by the winter, is again
in bloom. This inhabitant of the Caucasus is a large shrub with pale
gray-green leaves coated below with a thick mat of pale felt and large
pink or rose-colored flowers. This plant is so hardy that it is not im-
probable that a new race of Rhododendrons adapted to this climate
can be obtained by crossing it with R. catawbiense, R. maximum and
other hardy species. The felt on the lower surface of the leaves pro-
tects them from the attacks of the lace-wing fly which has been so
destructive to Rhododendrons here in recent years, but unfortunately
the leaves of the hybrids of R. Smirnowii which have been raised have
entirely lost this protection.

Cotoneaster hupehensis. The plants of this shrub in the Shrub Col-
lection and on the southern slope of Bussey Hill are again covered
with flowers. It is a broad tall shrub with wide-spreading, arching
branches and small clusters of white flowers which stand up well above
the leaves. The fruit is scarlet and lustrous. This species and the
two mentioned in the fourth number of these Bulletins, C. multijlora
calocarpa and C. racemiflora soongorica are the handsomest of the
Cotoneasters discovered by Wilson in western China and perhaps the
most valuable shrubs for the northern states which have been intro-
duced by the Arboretum in recent years. Cotoneaster divaricata and
C. nitens are both covered with their small pink flowers. The lustrous
leaves of these plants are attractive through the season.

23

Midseason Lilacs are in bloom nearly three weeks earlier than usual.
The best known of them, Syringa villosa, was raised at the Arboretum
nearly thirty-five years ago and from the Arboretum has been carried
into many American gardens. It is a large, round-topped shrub with
large leaves and compact broad or narrow clusters of pale rose-colored
or nearly white flowers which unfortunately have the disagreeable odor
of Privet flowers. In spite of the disagreeable odor of the flowers
this Lilac is a first-rate garden plant, and particularly valuable because
it does not begin to bloom until most of the flowers of the different
varieties of the common Lilac have faded. The Hungarian Lilac, S,
Josikaea, a tall shrub with violet-colored flowers in narrow clusters,
blooms a few days later than S. villosa. It is one of the least attrac-
tive of all Lilacs but crossed with S. villosa it has produced in France
a race of hybrids of great beauty to which the general name of iS.
Henryi has been given. One of the handsomest of these hybrids,
Lutece, is now covered with its large open clusters of red-violet flowers.
This is one of the handsomest Lilacs of recent creation and deserves
the attention of the lovers of these plants. Another of this race of
hybrids, S. eximia, blooms a few days later and has more compact
clusters of rose-colored or reddish flowers which after opening becom.e
light pink. Another of these midseason Lilacs, S. Wolfii, is also in
bloom. This is a little known species from northern China, and has
leaves like those of S. villosa, but the flov/ers are smaller and violet-
purple, and the flower-clusters are much larger. This promises to be
a valuable shrub in northern gardens. It blooms a few days earlier
than S. Koehneana, a native of Korea, a large shrub with slender
drooping branches and broad, unsymmetrical clusters of slender rose-
colored or pink flowers which have little perfume. Although this plant
has been growing in the Arboretum for sixteen years, it did not begin
to flower freely until two years ago.

Crataegus pinnatifida. In the thirty-five years this plant has been
an inhabitant of the Arboretum it has never been more covered with
flowers than during the past week. It is a native of eastern Siberia
and northern China and is an arborescent shrub or small tree. The
leaves are large, deeply lobed, thick, and lustrous on the upper sur-
face; the flowers are large, in many-flowered compact clusters, and are
followed by dull red, oblong fruit about three-quarters of an inch in
length. The fruit is less valuable for jelly than that of some of the
American Crabapples of the Mollis Group. It is esteemed by the Chin-
ese, however, who plant and carefully cultivate orchards of this Haw-
thorn in the neighborhood of Peking. If a selection of the six hand-
somest Hawthorns of the world was to be made many persons would
include in the six this Chinese species.

Cornus controversa. It is fortunate that the winter has had no bad
effect on this tree which promises to be one of the important intro-
ductions from eastern Asia. Like our Cornus alternifolia, it has wide-
spreading branches and alternate leaves, but the flower-clusters are
larger. It is a larger tree, sometimes growing in western China to
the height of sixty feet. It is now in bloom in the supplementary

24

Cornel Collection on the right-hand side of the Meadow Road and in
the Peter’s Hill Nursery where the largest specimen in the Arboretum
can be seen.

Early American Azaleas. The first flowers of the earliest of these
plants, R. {Azalea) Vaseyi, have already faded. R. nudiflora and R.
canescens have been in flower for a week on Azalea Path. Of the lat-
ter, which is a native of Massachusetts, there is a good mass on the
right-hand side of the Meadow Road in front of the Lindens which for
a long distance round has filled the air with delicate perfume. On
Azalea Path the flower-buds of the Appalachian R. {Azalea) calendu-
laceum are already open. In flower the most beautiful of Azaleas, no
other North American shrub equals it in the splendor of its bloom.

Berberis Vernae. Many of the new Barberries with deciduous leaves
discovered by Wilson in western China bloom much later in the season,
but a plant of Berberis Vemae in the collection of Chinese Shrubs on
the slope of Bussey Hill is now covered with its short clusters of light
yellow flowers. It is an attractive shrub with gracefully drooping
branches and small bright green leaves, and promises to be a good ad-
dition to the large number of hardy Barberries which can be grown
successfully in this climate.

Early Diervillas. The first of these plants to bloom, the Korean
Diervilla Jlorida venusta, is one of the hardiest and when in flower
perhaps the handsomest of all the species and hybrids of Diervilla, bet-
ter known as Weigela. The New England winter has no terrors for
this Korean plant, and it has not before been more thickly covered
with its handsome rose-colored flowers. It is growing in the Shrub
Collection and on Hickory Path near Centre Street. Varieties or hybrids
of Diervilla praecox, a plant of uncertain origin, raised recently in
France, have flowered well this spring in the Shrub Collection and de-
serve the attention of the public. The following varieties have been
conspicuous: Vestale with white flowers, Gracieux with pink and white
flowers, Conquerant with rose-colored flowers, and Fleur de Mai with
pink flowers.

Rosa spinosissima, var. altaica (or grandijiora) has not been hurt by
the winter and has been full of flowers as usual. This is one of the
largest and perhaps the handsomest of all the varieties of the so-called
Scotch Rose. It is a native of southern Siberia and in this climate often
grows six or seven feet tall and broad. The flowers are faintly tinged
with yellow and are produced in great numbers. It is one of the hand-
somest and hardiest of all single-flowered Roses which can be grown
in northern gardens; and as the plant produces suckers freely, and as
these are easily transplanted, there is no reason why this Rose should
not be more common than it is in American gardens.

Complimentary

NEW SERIES VOL. IV

NO. 7

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF

POPULAR INFORMATION

JAMAICA PLAIN. MASS. JUNE 5. 1918

The New Chinese Lilacs. Many of the liilacs discovered by Wilson
and other travellers in the recent explorations of western and northern
China are now so well established in the Arboretum and in a few other
American gardens that it is possible to form an opinion of their value.
Observations of the living plants show that too many species were
made when botanists had only the dried specimens sent home from
China to work with. Now that most of these plants have flowered
in the Arboretum and have been again studied it appears that Syringa
Wilsonii and S. Dielsiana are the same as S. tomentella; that S. Sar-
gentiana is a variety of S. Komarowii with a pubescent calyx; that
S. tetanoloha is S. Swegenzowii, and that S. Rehderiana is probably
only a pubescent form of S. tow-enfella. S. Komarowii Sargentiana is
not in the Arboretum collection and probably has not been introduced.
S. Rehderiana, S. Potaninii and S. verrucosa are still unknown in gar-
dens. As a garden plant the handsomest of the new Chinese Lilacs is
Springa rejiexa which Wilson discovered in western Hupeh. This is a
tall broad shrub with leaves resembling in size and shape those of S.
villosa. The flowers have long slender corolla-tubes and are borne in
long, wide-branched, open, drooping clusters; the flower-buds are red
but as the flowers open the corolla becomes dark rose color except the
inner surface of the lobes which is white. The wide drooping clusters,
and the contrast in the colors of the inner surface of the corolla-lobes
and its tube, make S. rejiexa one of the handsomest and most in-
teresting of the new Chinese Lilacs. Next in merit probably as an

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ornamental plant is Syringa Sweginzowii. This, too, is a tall shrub
but the branches are not as stout as those of S. rejiexa, and the leaves
are narrower, pointed at the ends and pale on the lower surface. The
flowers are produced in broad erect clusters and are pale rose color and
half an inch long. The flower-buds are of a peculiar brownish green
color, and as the flowers open gradually from the bottom to the top
of the cluster the contrast between the open flowers below and the
closed buds above give this plant a peculiar appearance during the
week or ten days the flowers are opening. This Lilac was first made
known through plants raised in the Arboretum of Max von Sivers at
Riga in Russia from seeds sent from some place in Mongolia or north-
ern China, the name of which is not recorded. Later it was found by
Wilson in western China, but the plants growing in the Arboretum
were obtained from the nursery of Regel & Kesselring in Petrograd.
S. Komarowii has leaves which resemble those of S. rejiexa but the
flowers are produced in short, compact, nearly cylindrical clusters nod-
ding on long stems. The flower-buds are bright red and very conspic-
uous, and the open flowers are deep rose color. This Lilac sometimes
blooms profusely when still a small bush. Syringa tomentella promises
to grow taller than the other new Chinese Lilacs for some of the plants
in the Arboretum are now nearly ten feet high. The leaves resemble
those of S. villosa, and the flowers are pale rose color or white, and are
borne in narrow erect clusters. None of the Arboretum plants have
ever produced many flowers and S. tomentella promises to be one of
the least desirable of the new Lilacs as a garden plant. Syringa Juli-
anae flowers earlier than most of the new Chinese Lilacs and the
flowers are already fading. As it grows here this is a compact low
shrub nearly as broad as high, and for several years has covered itself
with short clusters of rose-colored and white fragrant flowers. Re-
ated to the Chinese S. pubescens, it blooms much later than that and
other related species, and is an excellent addition to the list of Lilacs
which can be grown in our gardens. Syringa Woljii, which has dark
violet-purple flowers in short compact clusters, is another good garden
plant in this climate. This species, too, was first cultivated by Von
Sivers at Riga who obtained it from some place in northern China
which is not known. The other new Chinese Lilacs in the Arboretum,
S. Meyeri, S. microphylla, S. pinnatifolia and <S. yunnanensisi have
comparatively little decorative value and are curiosities rather than
good garden plants.

The Yellowwood or Virgilia. This tree, the Cladrastis lutea of
botanists, is now covered with long drooping clusters of pure white
pea-shaped flowers which make it one of the most beautiful trees in
the forests of eastern North America. It is a round-topped tree some-
times sixty or seventy feet in height, with pale smooth bark which
resembles that of the American Beech-tree, and large light green com-
pound leaves which turn clear yellow in the autumn before falling.
In the forest this is a rare and local tree, and is found growing,
usually on river cliffs, from western North Carolina to Tennessee, Ken-
tucky and northern Alabama, and in southern Missouri and northern
Arkansas. It is most abundant probably in the neighborhood of Nash-

27

ville, Tennessee. Sent to France by its discoverer, the elder Michaux,
it has been in cultivation for more thau a century. One of the first,
and perhaps the first specimen planted in the United States was stand-
ing a few years ago in the grounds of the Philadelphia Cricket Club
near that city. It was planted in Massachusetts, where it is perfectly
hardy, at least eighty years ago. This tree flowers well in France and
Germany, but rarely produces flowers in Great Britain where the sun
is not hot enough to ripen sufficiently the flowering wood. Here the
trees flower only once in two years and, with few exceptions, all in-
dividuals planted in the northern states flower the same year. Although
one of the handsomest trees that can be used for the decoration of
parks and gardens in the eastern states, the Virgilia seems to be less
commonly used here than it was seventy-five years ago. Fortunately
it can still be obtained in a few American gardens.

Deutzia hypoglauca. This plant was not injured by the severe cold
of the past winter and has now flowered for three years in the Arbor-
etum. It is a tall vigorous shrub with erect, much branched stems,
lanceolate, long-pointed leaves dark yellow-green on the upper surface
and pale below, and light orange-brown branchlets. The pure white
flowers are seven-eighths of an inch in diameter and are borne on
slender drooping pedicels in many-flowered compound, round-topped
clusters from three to four inches across. The broad, petal-like fila-
ments, which are rather shorter than the spreading petals and are
notched at the apex, form a tube rising from the center of the flower
from which the bright yellow anthers emerge. Deutzia hypoglauca
was discovered by Wilson in Hupeh but the plants in the Arboretum
were raised here from seeds collected in 1910 by Purdom on the moun-
tains of Shensi at altitudes between eight and ten thousand feet above
the sea-level. This may prove a valuable plant to cross with some of
the Chinese Deutzias with rose-colored flowers which are not really
hardy in this climate. It is a handsomer plant than D. parvifiora,
another Chinese species and an old inhabitant of the Arboretum where
it has proved to be one of the hardiest of all Deutzias. Sent by the
Arboretum to Lemoine at Nancy, France, it was successfully crossed
by him with D. gracilis. The result of this cross was Deutzia Lemoineiy
one of the handsomest and hardiest garden shrubs of recent creation.
One of the forms of D. Lemoinei, Boule de Neige, has been unusually
full of flowers this year.

The Persian Yellow Rose. This Rose is just opening its flower-buds.
It is the last of the yellow-flowered Roses which are hardy in the Ar-
boretum and a few days later than the Harrison Rose. The Persian
yellow Rose is a dwarfer plant of better habit than the Harrison Rose,
and the flowers are larger and of better color; and when it succeeds it
is the handsomest of the double-flowered yellow Roses. It is a form
of Rosa foetida, a beautiful and too little known Rose of southern
Russia, the Caucasus and Persia. The so-called Austrian Briar, with
petals yellow on the outer surface and dark copper color on the inner
surface, is believed to be a variety of R. foetida (var. bicolor). The Har-
rison Rose, which was raised in New York many years ago, is believed

28

to be a hybrid between the Scotch Rose and the Austrian Briar; it is
very hardy, flowers freely every year and grows to a large size. Un-
less, however, it is cut back occasionally it becomes straggling in habit
and unsightly. The yellow-flowered forms of the Scotch Rose, R.
spinosissima, var. hispida and var. lateola^ have been flowering well
this year; they are handsome and hardy plants, and although the flow-
ers soon drop their petals they are well worth a place in collections of
single-flowered Roses. R. spinosissima fulgida with single delicate
pink flowers is another variety of the Scotch Rose which has been
covered with flowers during the past week,

A pink-flowered Locust. One of the most distinct and beautiful
forms of the Locust-tree, Rohinia Pseudacacia var. Decaisneana, has
been unusually full of flowers during the past ten days. This tree,
which first flowered in 1862 in the nursery of M. Villeveille at Manos-
que in southern France, differs from all the other forms of this Locust
in its pale pink flow^ers. Many forms of the Locust have been raised
in European nurseries; they are all handsome and hardy, and could
they be protected from the borers which riddle the trunks and branches
of all forms of the Locust they would be as highly esteemed here as
they are in France and Germany. The variety Decaisneana must not
be confounded with R. viscosa, an American tree with pink flowers in
partly erect clusters, and well distinguished by the glandular viscid
hairs on the branchlets and flower-clusters. This tree is also flowering
in the Arboretum, as is the little Rose Acacia, Acacia hispida^ a hispid
shrub with large bright rose-colored handsome flowers, which is not
known to produce seeds but spreads widely and rapidly by underground
stems and may become a troublesome weed.

Viburnum cassinoides is blooming profusely but nearly three weeks
before its usual time for flowering. In cultivation this Viburnum is a
round-topped shrub from four to six feet high. The leaves are thick
and lustrous, and differ greatly in size and shape. The flowers are
slightly tinged with yellow and are borne in wide, slightly convex
clusters which also vary greatly in size. This plant appears even more
beautiful in the autumn than in June; for the fruit is larger than that
of the other summer-flowering American Viburnums, and at first when
fully grown is yellow-green, becoming pink and finally dark blue or
nearly black and covered with a pale bloom, fruits of the three colors oc-
curring together in the same cluster. This Viburnum has been gener-
ally planted in the Arboretum, and it is certainly one of the handsom-
est shrubs of eastern North America. Two other handsome American
Viburnums, V. bracteatum and V. molle, are in bloom and are interest-
ing to persons who like to see rare or little known plants. The former
grows only on the cliffs of the Coosa River near Rome, Georgia, and
the latter in southern Kentucky and very locally in southern Missouri.

Complimentary

NEW SERIES VOL. IV

NO. 8

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF

POPULAR INFORMATION

JAMAICA PLAIN, MASS. JUNE 12. 1918

Philadelphus. Few plants give greater beauty to northern gardens
than the Syringas or Mock Oranges. These are the unfortunate pop-
ular names of the different species of Philadelphus, for Syringa is the
botanical name of the Lilac, and Mock Orange is the popular name of
Prunus caroliniana^ a southern evergreen Cherry which is much planted
in the southern states as an ornamental tree and in making hedges.
The species of Philadelphus grow naturally in southeastern Europe and
the Caucasus, in the United States on the southern Appalachian Moun-
tains, in western Texas, on the southern Rocky Mountains, and in the
northwestern states, in Japan, Korea, northern and western China, and
on the Himalayas. In the last twenty years much attention has been
paid to the introduction of new species; artificial and natural hyorids,
too, have increased the number of these plants, and there are now
growing in the Arboretum some thirty species and a number of varie-
ties and hybrids. The flowering period of the Syringas extends through
six or seven weeks and, with few exceptions, none of them begin to
bloom until that of most Lilacs and of the Bush Honeysuckles has
passed. With its development in recent years Philadelphus has become
one of the important groups of garden shrubs to be ranked with the
Lilacs, Bush Honeysuckles, Viburnums and Azaleas. The species and
hybrids of Philadelphus are nearly all hardy in Massachusetts but the
white and usually fragrant flowers are their only attraction. They are
not particularly interesting in habit; the foliage is dull; the leaves fall
without change of color, and the fruit, which is a dry capsule, is
smaller and not more attractive than that of the Lilac. All the Syr-
ingas flower freely nearly every year; they need rich, well-drained soil,

29

30

and the presence of Ifme in it has no had eifects on them. Better than
most shrubs they can support shade and their ability to grov/ and
flower under trees make them valuable as undergrowth in border plan-
tations.

The Mock Orange of all old gardens is Syringa coronarius, the
eastern European s{>ecies. This plant was first cultivated in Eng-
land before the end of the sixteenth century and was probably one of
the first garden shrubs brought to America by the English settlers.
It is a medium-sized shrub often as broad as high. The flowers, too,,
are of medium size and faintly tinged with yellow. This shrub
has been somewhat neglected since so many species and hybrids
with larger and showier flowers have found their way into gardens.
This is unfortunate, for no other Syringa equals the old-fashioned
Mock Orange in the delicate perfume of its flowers. Varieties of this
plant with yellow leaves, with double flowers, and with narrow willow-
like leaves can be seen in the Arboretum collection, but none of them
have any particular decorative value. Among the American species
which should find a place in all gardens are P. inodorus, P. pubescens^
and P. micro phyllus. The first is a native of the Appalachian Moun-
tain region and grows to the height of six feet; it has arching branches
and large, solitary, pure white, cup-shaped, scentless flowers. By some
persons it is considered the most beautiful of all Syringas. P. pubes-
cens, often called P. grandifiorus or P. latifolia is also a plant of the
southern Appalachian region. It often grows to the height of twenty
feet; the branches are stout and erect; the leaves are broad, and the
slightly fragrant flowers are arranged in erect, from five- to ten-flow-
ered racemes. This plant is more common in gardens than the last
and when it is in bloom it makes a great show. P. microphyllus,
which rarely grows more than three feet tall, has slender stems, and
leaves and flowers smaller than those of any Philadelphus in cultivation.
What the flowers lack in size, however, is made up in fragrance which
is stronger than that of any other Syringa and perfumes the air for
a long distance.

The most distinct and the handsomest of the Asiatic species in the
Arboretum is Philadelphus purpurascens, discovered by Wilson in
western China. It is a large shrub with long arching stems from which
rise numerous branchlets from four to six inches long and spreading at
right angles; on these branchlets the flowers are borne on drooping
stalks; they are an inch and a half long, with a bright purple calyx and
pure white petals which do not spread as they do on most of the species
but form a bell-shaped corolla and are exceedingly fragrant. This is
one of the handsomest of the shrubs brought from western China to
the Arboretum. Philadelphus Magdalenae is another Chinese species
well worth cultivation. It is a tall broad shrub with arching stems,
small dark green leaves and pure white fragrant flowers an inch and
a quarter in diameter and arranged in drooping, leafy, many-flowered
clusters from six to ten inches in length. Philadelphus pekinensis
from northern China and Mongolia is a stout bush rather broader than
high which every year produces great quantities of small flowers tinged

31

with yellow. Another interesting garden plant, P. Falconerii, which is
certainly Asiatic and probably Japanese, has narrow lanceolate leaves
and fragrant flowers in from one- to six-flowered racemes, and is dis-
tinct in the shape of its leaves and in its long narrow petals. The
origin and history of this plant is not known.

Hybrid Philadelphus. The first hybrid Philadelphus which attracted
attention was raised in France before 1870 by a Monsieur Billard, and
is sometimes called in gardens Souvenir de Billard, although the correct
name for it is Philadelphus insignis. This hybrid is one of the hand-
somest of all the tall-growing Syringas, and its value is increased by
the fact that it is one of the latest of them all to flower. In a few
old gardens in the neighborhood of Boston great Syringa bushes occa-
sionally thirty feet high and correspondingly broad are sometimes
found. These plants are believed to be hybrids between P. coronarius
and some unrecognized species. It is called Philadelphus maximus.
Another hybrid, P. magnificus, sprang up in the Arboretum several
years ago and is supposed to be a hybrid between two American species,
P. inodorus and P. pubescens. It is a large and shapely shrub with
pure white only slightly fragrant flowers an inch and three-quarters
in diameter and borne in erect clusters. Philadelphus splendens flow-
ers very freely and when the flowers are open it is the showiest plant
in the Syringa Group.

Lemoine Hybrid Philadelphus. Several years ago the French plant
breeder Lemoine crossed P. coronarius with the Rocky mountain P.
microphyllus and obtained an entirely new race to which the general
name of P. Lemoinei was given. The original bush is intermediate
between the parents in size and in the size of the flowers. The flowers
are pure white, very fragrant and produced in profusion. From this
plant Lemoine raised many seedlings and secondary hybrids and these
vary from the original P. Lemoinei in size and in the size and shape
of the flowers. Taken as a whole the Lemoine hybrid Syringas form
one of the most beautiful groups of garden plants that has been created
by man. There are a number of these plants in the Arboretum col-
lection and they have been considered perfectly hardy here, but last
winter was too cold for some of them. P. Lemoinei itself and many
of its varieties are uninjured, but a few of the second hybrids were
killed to the ground but are now growing again from the roots. Un-
fortunately among the injured is the little plant called Conquete which
is usually considered the handsomest of these Lemoine Syringas. This
is the midseason for Philadelphus. The flowers of the Korean P.
Schneckii var. Jackii, which are always the first to open, faded nearly
two weeks ago, and the buds on some of the other species and hybrids
will not open for nearly a month.

The Sour Gum or Tupelo (Nyssa sylvatica) is now in flower. The
minute yellow-green flowers of this tree are hidden by the leaves and
will only be seen by persons who are specially looking for them. In
spite of its inconspicuous flowers the Sour Gum is one of the handsome
trees of eastern North America where it grows from Maine to Florida
and Texas. The greatest beauty of this tree is in its lustrous, dark

32

green leaves which in early autumn turn orange and scarlet, and then
are not surpassed in brilliancy by the leaves of any other American tree.
The bright blue shining fruits, which are about two-thirds of an inch
long, are also ornamental. This tree varies greatly in habit. Near the
coast it is low with a broad, flat or rounded had. Such trees are com-
mon on Cape Cod and near the northern shore of Long Island Sound.
In the interior, and on the slopes of the southern Appalachian Moun-
tains, where it grows to its largest size, it is often a hundred feet high,
with a tall massive trunk four or flve feet in diameter and a narrow
head of erect branches. Few American trees are better worth culti-
vating for the ornament of parks, but no one in these days plants a
Sour Gum. The long hard roots make it difficult to transplant, and
only small seedlings can be successfully moved. Those persons who
care only for “immediate effect,” the slogan of Americans of the
twentieth century who believe that money only is needed to secure
fully grown trees, have little use for the Sour Gum which wisely rebels
against the modern method of tree-planting which menaces the future
of too many American country estates.

Cornus kbusa. The flower-buds of this eastern Asiatic representa-
tive of our Flowering Dogwood were not injured by the winter which
ruined those of the American tree, .and the Japanese form of Cornus
kousa is now in bloom. It is a small tree or large shrub and the white
bracts which surround the clusters of flowers are smaller than those
of our native tree and are pointed. The form from western China has
rather larger flower-bracts than those of the Japanese plant. The fact
that the flower-buds of the Asiatic tree have not been injured by the
cold of the past winter adds to its value.

The Mountain Laurel (Kalmia latifolia) is in bloom. Occasionally
more plants on the bank at the northern base of Hemlock Hill have
flowered than are flowering this year, but the display is much better
than it was a year ago, and the Arboretum Laurels are now well worth
a visit. The Mountain Laurel is a remarkable plant. It can be seen in
full bloom near the shores of Mississippi Sound during the first week
of April, and travelling north one can see its flowers every day until
early July when the northern limit of its range in New Brunswick and
the northern shore of Lake Erie is reached. It grows as well in New
England as it does in regions where the climate is less rigorous, but
in New England the plants never grow to the size they attain on the
Blue Ridge of North and South Carolina about the headwaters of the
Savannah and Little Tennessee Rivers. Few plants have more beau-
tiful flowers; and the Mountain Laurel is a broad-leaved evergreen,
and broad-leaved evergreens which are hardy in Massachusetts, with
the exception of a few low under shrubs, can be almost counted on the
fingers of one hand. For of these plants only the Kalmia latifolia,
Rhododendron catawhiense, R. maximum and Andromeda florihunda
can be absolutely depended on. A few more Rhododendrons might be
added to the list, but after the experience of recent years it is not
safe to say that any foreign species or any hybrid Rhododendron will
prove hardy under all the weather conditions Massachusetts may
experience.

Complimentary

NEW SERIES VOL. IV

NO. 9

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF

POPULAR INFORMATION

JAMAICA PLAIN, MASS. JUNE 20, 1918

Populus Maximowiczii. This tree is a native of eastern Siberia,
eastern Saghalin and northern Japan. It is the largest tree of east-
ern Siberia where it sometimes grows eighty feet high with a trunk
six feet in diameter and a broad head of massive spreading branches.
On young trees the bark of the trunk is smooth and pale brown, but
on old trees it becomes thick and furrowed. This Poplar was first
sent to the Arboretum from Petrograd in 1878 but its distinctive char-
acters were not recognized until some years later. The plants now in
the Arboretum were propagated from the Petrograd tree which disap-
peared when the Poplar Collection was rearranged on the southern
slope of Bussey Hill. They are now twenty years old and about thirty-
five feet high. They have never been attacked by borers which make
the cultivation of the Balsam Poplars and some of the Cottonwoods so
difficult and unsatisfactory, and their leaves apparently have no attrac-
tion for leaf-eating caterpillars. The leaves are green and lustrous
on the upper surface, silvery white below, three or four inches long,
and two or two and a half inches wide. The fruit, which is fully
grown in May, unlike that of other Poplars, remains on the trees here
until September without opening.

Native and Foreign Trees. Populus Maximowiczii is not only the
handsomest and most satisfactory tree in the Poplar Collection but it
is one of the few large exotic trees with deciduous leaves which can be
recommended for general planting in the northern states. For the list
of such trees is a short one. It includes the Gingko, which stands alone
in its class and is one of the great trees of the world. The only sur-

33

34

vivor of a race which was once widely spread over the northern hem-
isphere, this inhabitant of eastern continental Asia is long-lived and
able to support extremes of heat and cold, and to grow equally well
in Massachusetts, Georgia and California. The Gingko is appreciated
and has been largely planted in the city of Washington, but in other
parts of the United States the beauty of this tree when it gets beyond
its juvenile habit is not understood. Pseudolarix is another Chinese
tree which is alone in its class and, although discovered only seventy
years ago, it has been long enough in this country to show that it is
perfectly able to adapt itself to the Massachusetts climate. This is
surprising for the home of Pseudolarix is on low miountain slopes not
far from the coast and south of the Yangtse River. The European
Larch, although less picturesque than the Larch of northeastern North
America, is a larger and more valuable tree, and the experience with
it in New England shows that it is a tree which can be depended on
to grow here rapidly to a large size.

The two Silver Poplars of Europe {Populus alba and P. canescens)
flourish in the United States where they have grown to a large size
and are as much at home as they are in their native countries. The
pale color of the foliage of these trees is unlike that of any of the
American species, and their hardiness and vitality make them useful
for planting in exposed positions. The Silver Poplar of northern China
(P. tomentosa) is one of the handsomest of all Poplar-trees. It has
grown well in the Arboretum but it is too soon to form an opinion of
its value in this country. Two European Willows, Salix alba, and «S.
fragilis, and some of their varieties, have become completely naturalized
in the northeastern states where they grow as large or even larger than
in Europe and are important additions to the North American silva.
The Chinese Weeping Willow {S. babylonica) is not always perfectly
hardy in Massachusetts, but further south is valued as an ornamental
tree. The so-called Wisconsin Willow, a natural hybrid between this
Chinese Willow and S. alba, and other hybrids of the same parentage
are useful ornamental trees in the northern states.

Cercidiphyllum is the largest deciduous-leaved tree of Japan, and
although it was introduced into the United States only forty years ago
it gives promise of becoming a permanent addition to the trees of the
largest size which can be successfully grown here. The Chinese White
Mulberry {Morus alba) is a larger and hardier tree than the Mulberry-
tree of the eastern states, and is perfectly at home here. Probably
the most generally useful, however, of the large deciduous-leaved
trees which have been brought into the northern states is the Ailan-
thus of northern China which must have been growing here for nearly
a century. It grows rapidly and is perfectly hardy, and it can resist
the heat, drought and dryness which trees have to suffer in our cities
better than any other tree with the exception, perhaps, of some of the
Poplars. The Ailanthus, too, produces handsome wood valuable in cab-
inet-making.

The Japanese White Oaks are handsome trees and produce valuable
timber. They grow well in the Arboretum and give every promise of

35

living here for many years. Under the most favorable conditions in
Japan they do not become as large as our native White and Bur Oaks,
and do not produce more valuable timber than these and several other
American White Oaks. All foreign Oaks which can be induced to live
here are proper inhabitants of the Arboretum where they are needed
for study and public display, but for general planting the Oaks of other
countries will never be used in New England in preference to the
native species. Of all the Elm-trees of the world not one equals in
grace and beauty the White Elm of eastern North America {Ulmus
americana). It is a true lover of the country, however, and only shows
its greatest beauty in the deep moist soil of a New England intervale.
Moved to the city it soon languishes, for it resents city conditions
of overdrained soil, smoke and bad air. One of the so-called English
Elms is better able to thrive in cities where the American Elm fails,
and in Boston and its suburbs the English tree has been growing
for more than a century and has proved itself valuable. None of the
exotic Ash-trees are really valuable here. For general planting in
the eastern United States no Ash is as good as the American White
Ash (Fraxinus americana) for the decoration of parks and roadsides
and the production of timber. The European Ash {Fraxinus excelsior)^
which is a magnificent tree in some parts of Europe, is a miserable
failure here, and the great Ash-tree of northeastern continental Asia
and northern Japan (F. mandshurica) can barely be kept alive in New
England. European Birch-trees grew well in the northern states until
they were attacked by a borer which destroyed them by thousands.
The slender drooping branches of Betula pendula make it an inter-
esting and attractive object but it is not as handsome a tree as the
native Canoe Birch {Betula papyrifera) which is the handsomest of the
white-barked Birches and in one of its forms exceeds all other Birch-
trees in size. Betula Maximowiczii with pinkish bark, and a native
of northern Japan, is, however, a handsomer tree than the Canoe
Birch. It has been growing in this country for twenty-five years,
and although it has grown well and is perfectly hardy here it is too
soon to speak of its permanent value.

The pale gray bark of the trunk and branches of the American
Beech makes it in winter the most beautiful of all Beech-trees, but
as a planted tree it does not behave as well or grow as rapidly as the
European Beech which, in spite of its darker colored bark, is a better
tree for the decoration of our parks. The northern Linden {Tilia glabra
or americana) is a noble tree in the northern forests where in deep
moist soil it sometimes grows to the height of one hundred and thirty
feet and makes a trunk four or five feet in diameter, but it does not
take kindly to cultivation in a climate as warm as that of Massachu-
setts. Planted trees grow slowly here; the leaves are usually disfigured
by red spiders and turn brown and fall during the summer. There are
a number of Linden-trees in the middle and southern states but little
is yet known about them as cultivated trees, and a planter who wants
Linden-trees had best use some of the European species. There are
five of these, and the three species of western Europe have been so
thoroughly tested in the United States that it is possible to say that

36

they are among the most valuable trees which have been brought
here from foreign countries. The most satisfactory of them here
is Tilia vulgaris, a widely distributed but rather rare tree in Eu-
rope and believed to be a natural hybrid between the other western
European species T. platyphyllos and T. cordata. There are large
specimens of this Linden in the suburbs of Boston. No American
Horsechestnut or Buckeye can compare in size or in the beauty of its
flowers with the species of southwestern Europe {Aesculus Hippocas-
tanum), which is well known to many Americans who have never heard
that there were Horsechestnut-trees growing naturally in the United
States. The European Horsechestnut is another of the great trees of
the world. It is as much at home here and growls to as large a size
as it does in western Europe. Few trees have more conspicuous flow-
ers or foliage of deeper green. It thrives, however, only in deep rich
soil and usually resents city conditions. In some old gardens in Salem,
however, there are as noble Horsechestnuts as can be found in the
United States or Great Britain. It is a miserable street tree, as can
be seen in Paris, w’here the leaves turn brown and fall by midsummer,
and in New York and Boston where fortunately it has not been gen-
erally planted. Among the Maples of large size w^hich have been
planted in the eastern states only the so-called Norw-ay Maple {Acer
platanoides) has shown real power to flourish here. It is a smaller and
less beautiful tree than the native Sugar Maple, but the Sugar Maple,
too, resents city conditions and objects to living at the seashore, and
as the Norway Maple has proved a valuable tree for city and seashore
planting it must be considered one of the really valuable foreign trees
introduced into this country. The Old World Walnut-tree {Juglans
regia) sometimes called English Walnut or Persian Walnut, although
it is a native of China, is a handsomer and more valuable tree than
any of the American Walnut-trees, but unfortunately it is only doubt-
fully hardy in the northeastern states and will probably never grow
to a large size here or produce the great crops of nuts and the timber
which make this such a useful tree in many parts of the world. Chest-
nut-trees (Castanea) are fast disappearing from the United States
as the Chestnut-tree disease spreads, and there is now little interest
in drawing a comparison between the American and foreign species.
The European Chestnut is not hardy in Massachusetts. The Japanese
Chestnut is a small tree of no great value, and the Chinese Castanea
mollissima, which it is hoped may prove resistant to the disease, has
only been in the country for fifteen years. It has proved hardy in the
Arboretum and produces a little fruit here.

It appears therefore from the experience gained in Massachusetts
during about a century that only the following deciduous-leaved trees
of large size have proved themselves to be worth general planting in
the northeastern states for ornament or timber: — the Gingko, the
Pseudolarix, the European Larch, three species of Poplar, three Wil-
lows and their hybrids, the Cercidiphyllum, the White Mulberry, the
Ailanthus, the European Beech, the English Elm, one Birch, three
Lindens, the European Horsechestnut, and the Norway Maple, twenty
in all. At the end of another century the record of the Arboretum
will, it is to be hoped, be able to tell a story of greater successes.

Complimentary

NEW SERIES VOL. IV

NO. 10

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF

POPULAR INFORMATION

JAMAICA PLAIN, MASS. JUNE 27. 1918

The English Elm. In the discussions of the English Elm which oc-
casionally appear in the Boston papers surprise is expressed that dif-
ferent individuals of this tree differ in general appearance and in the
size of the leaves, showing perhaps that it is not generally known
that there are four distinct species of Elm-trees now growing natur-
ally in England. This confusion in regard to these trees is of long
standing, for Linnaeus one hundred and sixty-five years ago believed
that all the Elm-trees of Europe were of one kind to which he gave
the name of Ulmus campestris, a name which must be abandoned as
the four British trees and an Elm-tree of northern and eastern Europe
are included in his description.

Ulmus procera. This is the name now adopted for the tree which is
generally known as English Elm in Boston where it has proved one of
the best foreign trees ever planted in Massachusetts. It has been
growing here for more than a century, and nearly one hundred years
ago Major Paddock had a nursery at Milton for the propagation and
sale of this tree. Probably no tree, native or foreign, which has been
planted in the neighborhood of Boston has grown to such a large size.
The Paddock Elms, which stood on Tremont Street in front of the
Granary Burying Ground, were of this species, as were the great Elms
on the Tremont Street Mall of the Common which were killed by the
Subway. The Elm-trees on each side of the Shaw Monument opposite
the State House are of this species, and there are still large speci-
mens in the suburbs of the city. This is the common Elm-tree of
southern England where it grows usually in hedge-rows, although it

37

has been largely planted in parks. It often grows one hundred feet
tall with a massive stem covered with dark deeply furrowed bark,
spreading or ascending branches which form a comparatively narrow
oval head, and slender branchlets thickly covered during their first year
with down. The leaves are broadly oval or ovate, oblique at the base,
dark green and rough on the upper surface and covered below with
soft down; they are from two to three inches long with about twelve
pairs of veins, and their stalks are only about one-fifth of an inch in
length. This tree very rarely ripens fertile seeds in England or in this
country, but it produces suckers in great numbers and is propagated
entirely by means of these. As this tree so rarely produces seeds few
varieties are known, but a small-leaved Elm (var. viminalis) is believed
to be a seedling of it. Of this little Elm there are forms on which
the leaves are blotched with white and with j'ellow.

Ulmus foliacea, or nitens. This is another English Elm which differs
from the last in its paler bark, in its smooth or nearly smooth branch-
lets, that is without a covering of down and in its leaves which are
smooth and, shining on the upper surface, only slightly downy below
early in the season and from two to three and a half inches long.
This tree produces fertile seeds in abundance and seedlings are raised
in European nurseries. It is widely distributed over central and south-
ern Europe and grows also in northern Africa and eastern Asia. Sev-
eral geographical forms are recognized; the most distinct of these are
the Cornish and the Guernsey Elms which are trees of medium size
with erect growing branches which form a narrow pyramidal head.
Plants of these two forms are not always hardy in Massachusetts.
Another form, common in Hertfordshire, is a large tree with wide-
spreading and pendulous branches and at its best, although not so tall, is
almost as handsome as our American White Elm {U. americana). An-
other form (var. umbraculifera) from Persia and Armenia is interesting
from its compact globose head. This tree might perhaps be made use-
ful in formal gardens. On many trees of Ulmus foliacea the branches
are furnished with corky wings (var. suberosa), and the so-called
English Elms with such branchlets occasionally seen in this country
are usually of this variety. The seedling trees of this Elm which have
been imported from European nurseries vary in habit, in the size of their
leaves and in their hardiness; and the unhealthy and generally unsat-
isfactory Elm-trees which have been planted in considerable numbers
in eastern Massachusetts during the last twenty years are in nine cases
out of ten seedling forms of U. foliacea.

Ulmus glabra. This is another widely distributed European Elm
which is often called Scotch Elm or Wych Elm by English-speaking
people. This is a tree with a trunk and branches which remain smooth
for many years. It can always be recognized, too, by the large ob-
tuse buds covered by pale brown hairs and by its dark dull green
leaves abruptly pointed or three-lobed at the apex, oblique and un-
symmetrical at the base, rough above, downy below and from four to
six inches long with stalks shorter than those of other Elm-trees.
This tree does not sucker but produces fertile seeds in great quanti-
ties, and more abnormal seedling forms of this tree have been raised

39

than of any other Elm, The well-known Camperdown Elm is a form
of this tree with regularly pendulous branches which is often planted
in suburban gardens to make natural arbors; another form (var. pen-
dida) has horizontally spreading pendulous branches which form an
unsymmetrical, flat-topped head. There is a form with erect branches
forming a narrow pyramidal head and others with leaves more coarsely
toothed than those of the ordinary form and with purple and other
abnormal leaves. This is perhaps the least beautiful of all the species
of Elms. The abundant seeds are blown great distances and germinate
80 readily that seedlings are often troublesome weeds which if neg-
lected for a few years become difficult to eradicate. For several years
the leaves of this tree in the neighborhood of Boston have been turned
brown and often killed by a leaf-mining insect which attacks this spe-
cies but no other Elm-tree.

Ulmus minor, sometimes called U. sativa, is a small-leaved Elm-tree
of large size which is rather closely related to U. foliaceu. Although
common in the eastern counties of England, it is possible that this
tree cannot be seen in the United States outside of the Arboretum.

Ulmus hollandica. This general name has been given to a race of
natural hybrids betv/een U. foliacea and U. glabra, among which are
.some of the handsomest and most valuable of the European Elms. To
the best known in this country of these hybrids the name Ulmus hol-
lamdica vegeta has been given. This tree was raised in a nursery at
Huntingdon about the middle of the eighteenth century and is usually
called the Huntingdon Elm. This tree often grows one hundred feet
high with a massive trunk and spreading and ascending branches which
make a vase-shaped head which readily distinguishes this tree from
other Elms. It can be seen to good advantage in Cambridgeshire,
England, especially in Cambridge, where there is a noble avenue of
the Huntingdon Elm. A tree of this hybrid which grew in the grounds
of Magdalen College at Oxford was believed to be the largest tree in
Great Britain, In April, 1911, this tree was blown down and was
found to be one hundred and forty-two feet high v/ith a trunk twenty-
seven feet in circumference at five feet above the ground. In this
country this hybrid Elm grows more rapidly than other Elm-trees, and as
it produces suckers it can be easily multiplied. It is not common here,
however, although in the neighborhood of Boston specimens not more
than sixty years old have already grown to a large size. The var.
belgica of this hybrid is the Elm which has been most often planted as
a street and roadside tree in Belgium and Holland. It is a tall tree
with a straight, rough-barked trunk, a broad head of rather erect
branches, and dark green leaves slightly roughened above and cov-
ered below with soft down. As this tree grows in Holland it is one
of the handsomest and most desirable trees for shading city streets.
This Elm appears to be little known in the United States; it is grow-
ing well in the Arboretum, but it has not been here long enough yet
to show if it will be of permanent value in New England. The so-
called Dutch Elm, Ulmus major of many English dendrologists and a
common tree in English parks, is probably another hybrid of the same
parentage (U. hollandica var. major). This is a very large tree with

40

a short trunk covered with rough bark, wide-spreading branches fur-
nished with corky wings, and dark green leaves lustrous and nearly
smooth on the upper surface and slightly downy below. As this tree
produces many suckers it can be easily multiplied.

Ulmus laevis. This is a comm.on Elm in northern Russia and in some
parts of Scandanavia, and occurs occasionally in Denmark and the
Balkan countries. It has been growing in the Arboretum since 1888,
and is now fifty-five feet tall with a short trunk, a broad pyramidal head
and dark green foliage. Botanically this Elm is closely related to the
American White Elm (Ulmus americana) but differs from it in the
thicker coat of down on the lower surface of the leaves and in its
larger and sharper-pointed buds. The leaves of this tree unfold
here earlier than those of any other Elm. It is probably extremely
rare in the United States, but American tree lovers can wisely learn
more about it.

The Arboretum Collection now contains sixty-two different Elms and
includes all the known species with the exception of the four Hima-
layan Elms and the Mexican Elm which are not in cultivation and two
species from the southern United States which are not hardy here.
With few exceptions the important and interesting varieties and hybrids
are represented in the collection. Many of the plants are still too
small to produce fruit or to show the habit of mature trees, but as
a whole the collection offers a good opportunity for the study of the
leaves and branchlets of Elm-trees.

A good Rhododendron. To a Rhododendron which is growing in Mr.
Hunnewell’s garden at Wellesley the name of Glennyi has been given.
This name is probably not correct, at least it is not found in the cat-
alogues of garden Rhododendrons. There was once, however, in Eng-
land a Mr. Glenny who raised hybrid Rhododendrons, for on the 5th
of February, 1838, at a meeting of the Royal Horticultural Society in
London, “Mr. George Glenny exhibited a Rhododendron said to have
been raised by himself from seed. It did not appear different from a
variety raised some years since by Mr. Waterer, of Knaphill, and called
in the gardens R. jndcherrimum. It is said to have been a hybrid
between R. arboreum and R. caucasicurn, and was raised at Knaphill
in 1832; it has pink flowers.” The plant in Mr. Hunnewell’s garden
is evidently a hybrid of R. caucasicurn, and has been growing there
for fully fifty years. The original specimens were certainly imported
from England and are now round-topped bushes about six feet high.
For at least thirty years they have never suffered from heat or cold
and have never failed to bloom freely. The leaves show the influence
of R. catawbiense but the size of the flower-clusters and the size of
the white flowers, which are a good deal like those of R. Boule de
Neige, point to R. caucasicurn. The early flowers, for this is one of
the earliest of the hardy Rhododendrons to flower in this climate, show
too the caucasicurn influence. But whatever name it should bear and
whatever its parentage this Rhododendron is a valuable plant, for it
is certainly one of the hardiest hybrid Rhododendrons which have been
planted in this country. There are only small plants in the Arboretum
Collection where it has not yet flowered.

Complimentary

NEW SERIES VOL. IV

NO. n

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF

POPULAR INFORMATION

JAMAICA PLAIN, MASS. JULY 5, 1918

Summer-flowering Trees. Several interesting trees will flower in
the Arboretum at different times during the next two months. Among
these summer-flowering trees are the Chinese Sophora japonica, the
Maackia of eastern Siberia, Acanthopanax ricinifolius from northern
Japan, the arborescent Aralias from the southern United States and
eastern Asia, the Korean and Chinese Evodias, the Sour Wood or Oxy-
dendrum from our Southern States, the Chinese Koelreuteria and one
of the American Catalpas (C. hignonoides). It is interesting that only
three of these trees, one of the Aralias, the Sour Wood and the Cat-
alpa are American, and that the others have been brought to this coun-
try from eastern Asia. The most important group, however, of sum-
mer-flowering trees is

The Lindens. The flowers of a few of the early flowering species of
these trees, like the European Tilia platyphyllos and its varieties, and
T. vulgaris, and the American T. neglecta, are already open; and dur-
ing the next two or three weeks the flowers of different species of Lin-
den-trees will open in the Arboretum and attract the bees to their rich-
est harvest. Linden-trees are very generally distributed in all the
temperate regions of the northern hemisphere with the exception of
western North America and, in addition to numerous species, several
hybrids are cultivated. All the species are very similar in flower and
fruit, and chiefly vary in the size and shape of the leaves, in the pres-
ence or absence of hairs on the leaves and branchlets, and in the nature
of their hairy covering when it occurs. A fact which is not easy to
explain is the presence in the flowers of all the American species of

41

42

petal-like scales opposite the petals and connected with the clusters of
stamens, while in the flowers of all the Old World Lindens such scales
do not exist. Another fact about Lindens which is not easy to explain
is that the European species grow much better in Massachusetts than
the species of eastern Asia, although as a rule European trees do
not succeed here as well as the trees of eastern Asia. The flve Euro-
pean Lindens and the species from the Caucasus all flourish in the
Arboretum and some of these trees have grown in New England to a
large size. The Asiatic species, however, although they have not been
many years in this country, give little promise of becoming really
good trees here. Tilia japonica, which has been growing in the Ar-
boretum for twenty-five years, although still a small tree, is, however,
perfectly healthy; it is related to the small-leaved Linden of Europe
(T. cordata) and, like that tree, is one of the latest Lindens to flower
here. The graceful drooping branches and pale under surface of the
leaves make this small tree attractive, and it is the first of the Lin-
dens here to unfold its leaves in the spring. The common Linden of
the north {T. glabra or americana) as was recently explained in one
of these Bulletins, is not as good a tree here as several of the Euro-
pean species', but there are several other American Lindens which have
been overlooked by American planters, and misunderstood or neglected
by American botanists, and among them are handsome trees. Some
of these are growing in the Arboretum, and it is not improbable that
the Arboretum collection will be improved at the end of a few years
when it is hoped the American Lindens will be better known.

Lindens have always been more valued as ornamental and shade
trees in Europe than in the United States. No other trees have been
more generally planted in some of the countries of central Europe, and
in these countries attention has been paid to the collection and perpet-
uation of several interesting and valuable varieties and hybrids. The
Arboretum collection, which is arranged in the meadow on the right-
hand side of the Meadow Road, now contains forty-five species, varie-
ties and hybrids. Many of these trees have flowered for several years,
and some of them are large enough to show the habit of the different
species when thirty or forty years old. Judging by the Arboretum
collection, the handsomest of these trees which can be grown in this
part of the country are the European T. vulgaris, T. cordata, T. to-
mentosa, and T. petiolaris and the American T. heterophylla, T.
Michauxii and T. neglecta, and the hybrid T. spectabilis. This tree is
believed to be a hybrid of T. americana with T. petiolaris or T. tomen-
tosa. It has leaves as large as those of the American tree but silvery
white on the lower surface. The variety Moltkei has rather thicker
but equally large leaves. These trees are among the handsomest of all
Lindens, and no Lindens in the Arboretum collection grow more rap-
idly.

Some good shrubs. A correspondent asks the Bulletin to name the
twelve best shrubs of recent introduction. The task is not an easy
one for two persons rarely agree in their opinion of the merits of any
plant for any particular purpose. The best shrubs in the sense which
our correspondent means are those which will be hardy over a large

43

part of New England and the middle and middle western states, that
is in those parts of eastern North America where gardening is most prac-
ticed. This means that Rhododendrons, Azaleas and other plants of the
Heath Family must be excluded from the list, for plants of this family
will not grow in soil impregnated with lime. The selection is more diffi-
cult now than it would have been a year ago, for the past winter has
hurt some of the shrubs which might have been included in such a
list but which have not been able to support the excessive cold to
be expected occasionally in the northeastern states. As they were un-
injured by the cold of last winter the following twelve shrubs may at
least be considered hardy whether all our readers approve or not of
our selection. In our opinion four of the Cotoneasters of western
China must be included in any list of the twelve best shrubs of recent
introduction; they are C. hupehensis, C. multijlora var. calocarpa,
C. racemijlora var. soongorica, and C. nitens. C. hupehensis is a broad,
tall and shapely shrub with bright green leaves and white flowers
which make the plant as conspicuous as any Spiraea. The flowers are
followed by small scarlet fruits which are a good deal hidden by the
leaves. C. multijlora var. calocarpa is a large shrub with slender,
gracefully arching stems, and blue-green leaves. The flowers are borne
in erect clusters on short lateral branchlets which rise above the arch-
ing stems, and few shrubs are more graceful in habit or more charm-
ing in the arrangement of their flowers; the fruit is scarlet and about
a quarter of an inch in diameter. C. racemijlora var. soongorica is
also a large and vigorous shrub with arching stems. The flowers are
white and a little larger than those of C. hupehensis-, the leaves are
dull blue-green in color, and the fruit is large and showy. Many per-
sons consider this the handsomest of the Chinese Cotoneasters. C. nit-
ens is also a large broad shrub; the leaves are dark green and very
lustrous; the flowers are red, and the fruit is black. Of these four
Cotoneasters the last has the handsomest foliage but the smallest
flowers and fruit.

Two Roses can properly find a place in this list of twelve shrubs,
the Chinese Rosa Hugonis and the Korean R. Jackii. The former has
pale yellow flowers and has often been described in these Bulletins;
it is one of the handsomest of all single-flowering Roses and one of
the most important introductions of recent years. Rosa Jackii bears
clusters of white flowers like those of R. multijlora, but the flowers
are nearly twice as large and open two or three weeks later. This is
one of the last of the Roses to flower here and is now in bloom in the
Shrub Collection.

Two Lilacs recently described in these Bulletins, can be included in
the list, Syringa Sweginzowii from northern China and S. rejlexa from
western China. Diervilla Jlorida var. venusta, introduced a few years
ago from Korea, is perfectly hardy and the handsomest of all the spe-
cies, varieties and hybrids of Diervilla in the large Arboretum collec-
tion. It can fairly be considered one of the best shrubs introduced
into this country by the Arboretum in recent years. Prinsepia sinensis
from northern China properly finds a place in this list. It is perfectly
hardy; the leaves unfold earlier in the spring than those of any other

44

shrub in the Arboretum and are soon followed every year by innu-
merable yellow flowers. The hardiness, rapid growth, sturdiness and
the abundant spines on the stems should make this a good hedge plant.

Of the numerous species of the genus Corylopsis cultivated in the
Arboretum only the Japanese C. Gotoana escaped serious injury last
winter. Like all the species of this genus, it bears drooping clusters
of yellow flowers which appear before the leaves, which resemble
those of the Witch Hazel to which Corylopsis is related. This beau-
•tiful shrub has flowered here now for several years and has shown
itself worthy of a place among the best plants of recent introduction.

The list can be completed with Aesculus georgiana and Spiraea
Veitchii. The former is a dwarf Buckeye from central Georgia, with
compact clusters of large red and yellow flowers. This shrub was in-
troduced into gardens by the Arboretum and has now flowered here
for several years. As it was not injured by the cold of last winter
it can probablj’^ be considered hardy in Massachusetts. Spiraea Veitchii
is one of the plants discovered by Wilson in western China. It is a
large shrub sometimes ten or twelve feet high, with gracefully arching
stems above' which the wide clusters of white flowers stand at the
ends of short lateral branchlets. It is one of the latest of the white-
flowered Spiraeas to bloom and is, now in flower in the Arboretum
where it has proved entirely hardy.

The fruits of Acer tataricum are already bright red and make this
little tree a conspicuous and attractive object. The bright blue fruits
of Lonicera coerulea and its numerous geographical varieties, and the
scarlet, red and yellow fruits of the Tartarian Honeysuckle and its
varieties and hybrids are now ripe. And from now until March per-
sons interested in the handsome fruits of trees and shrubs can find
them in great variety in the Arboretum.

With this issue these Bulletins will now be discontinued until the
autumn.

Complimentary

NEW SERIES VOL. IV

NO. 12

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF

POPULAR INFORMATION

JAMAICA PLAIN. MASS. OCTOBErTiT 1 9 1 8

Crabapples in Autumn. The beauty of the Crabapples of North
America and eastern Asia in spring when they are covered with their
pink, rose color or white flowers has often been described in these
Bulletins. That few trees produce handsomer or more abundant fruit
is perhaps not yet generally known or the value of these trees for the
decoration of the autumn garden fully appreciated. All the Crab-
apples, including the species from Florida and Oregon, are hardy in
the north. They are all indifferent to the presence of lime in the soil
and therefore can be grown successfully in parts of the United States
where it is impossible to cultivate many plants like Rhododendrons and
Azaleas to which the presence of lime is fatal. Of the large groups
of shrubs and small trees of general and wide cultivation in this coun-
try—Lilacs, Syringas, Crabapples, Viburnums, Hawthorns, and Cornels
—none equal the Hawthorns and Crabapples in the size and brilliancy
of their fruit. The fruit of the American Crabapple is larger than
that of the Asiatic species, depressed-globose except in the Oregon
species, light green or pale yellow, covered with a waxy exudation,
and very fragrant. The fruit of the Asiatic species is red, yellow
with a red cheek or greenish, and varies in size from that of a small
pea to a diameter of an inch and a half. On some species the fruit
falls as soon as it is ripe and on others it persists until spring. There
are many natural hybrids of these Asiatic plants and, as is the case
in several other genera, the hybrids are often more valuable as garden

45

46

plants than their parents; and as all Apples hybridize very freely it is
probable that large sowings of the seeds of the plants gathered in a
collection like that of the Arboretum, which contains all the species
and many varieties and hybrids, will yield forms of greater value as
garden plants than those now known.

It is hard to say which is the handsomest of the Asiatic Crabapples
at this season of the year. The showiest fruit is perhaps that of
Malus prunifolia. This tree has been considered a native of Siberia
and northern China, but although it has been known in western gar-
dens for more than one hundred and fifty years its home as a wild
tree is not yet known. It is evidently one of the rarest Crabapples
in American gardens. The fruit is oblong, broader at the base than
at the apex, nearly an inch and a half in length, very lustrous, bright
red, or yellow with a red cheek. It differs from many of the other
Asiatic Crabapples in the large, persistent, erect calyx. In this coun-
try at least the fruit is less abundant than that of many other species.
The Rinki Crab, which is now believed to be a variety of Malus prun-
ifolia, produces large crops of fruit in the Arboretum; this is smaller
than the fruit of M. prunifolia and is often nearly globose, red, yel-
low or green on different trees. The Rinki is a native of northern
and western China, and for many centuries has been cultivated by the
Chinese as a fruit tree. From China it was early carried to Japan
where it was generally cultivated for its fruit until replaced by the
American and European apples of larger size and better quality. The
handsome and abundant fruit of the Rinki should secure for it a place
in American gardens.

Among hybrids of Malus prunifolia with other species, principally
with the Siberian M. baccata, are plants which are conspicuous in the
abundance and beauty of their fruit which, although somewhat smaller
than that of M. prunifolia, is equally brilliant in color. This hybrid,
which is still without a name, is well worth attention. Plants of M.
floridana are unusually full of fruit this year which on some trees
almost hides the leaves, giving the plant the appearance of fountains
of old gold. The fruit on different plants varies somewhat in color
and in size; from some it drops in the autumn as soon as it is ripe,
and on other trees it remains until spring. Such trees furnish birds
with great quantities of appreciated winter food. From many points
of view this Crabapple is one of the very best large shrubs or small
trees which can be grown in the northern United States. It is per-
fectly hardy and of excellent habit; for forty years it has never failed
to cover itself with flowers which, bright rose color in the bud, are
white after the buds have opened; and there have not been many au-
tumns when the fruit has not been as abundant as it is this year.
Malus Arnoldiana, a natural hybrid of M. floridana with some other
species, originated in the Arboretum. It has the habit of M. floridana
but the flowers and fruits are nearly twice as large. Some persons
consider this hybrid the handsomest of the Crabapples and there are
certainly no more beautiful objects in the Arboretum this Autumn.
The different forms of the Japanese Malus Sieboldiana are all hand-

47

some in the autamn. The typical form is a low shrub broader than
high with arching stems, and there is an arborescent form of excellent
habit. This Crab produces great quantities of fruit which is not larger
than a small pea and is bright red on some individuals and yellow
on others. It has the merit of flowering later than the other Asiatic
Crabapples. The variety calocarpa of M, Sieboldiana has larger
flowers and fruit, and is a large arborescent shrub. As a flowering
plant and when its bright red lustrous fruit is ripe it is one of the
handsomest Crabapples. To Dr. William S. Bigelow of Boston, who
sent the seeds to the Arboretum from Japan, western gardens owe
this beautiful plant which is not known in a wild state. The small
globose fruit of M. baccata, a common tree in northeastern Asia,
varies considerably in size and in its shades of red, but all the forms
are shapely trees handsome in spring and autumn. A Korean variety,
var. Jackii, still rare in gardens, has perhaps the most brilliant fruit
of any of the forms of M. baccata. A northern form, var. mandshurica,
has larger fruit, and the flowers are more fragrant than those of any
other Asiatic Crabapple. Attention may be called again to the value
of Malus Sargentii as an autumn and winter plant. This is a shrub
from northern Japon which grows only a few feet high but spreads
by semiprostrate stems to a wide diameter. The scarlet fruit, which
is produced in great quantities, is not apparently appreciated by birds
and remains in good condition on the branches till spring. M. trans-
itoria from western China has produced fruit in the Arboretum this
year for the second time. It is ellipsoidal in shape, rose pink, darker
on one side than on the other, very lustrous and about three-quarters
of an inch long. The fruit of few Crabapples is more distinct and
beautiful. Only a few plants in the Collection are mentioned in this
Bulletin. Many others are equally interesting, and a study of the
group will show possibilities for garden decoration which few persons
in this country realize. In planting Crabapples it is well to remember
that they only really thrive in rich, well-drained soil, that they require
plenty of room in which to display their greatest beauty, that they
are often attacked by the San Jose Scale which is easily controlled by
spraying, and that their leaves are preyed on by the caterpillars which
feed on the leaves of the Apple-trees of orchards.

Autumn Flowers. A few flowers can still be seen in the Arboretum,
although the number of trees and shrubs which bloom in Massachusetts
during the first weeks of October is not large. Aralia spinosay
the Hercules’ Club of the middle and southern states, is still covered
with its great terminal clusters of white flowers. These great flower-
clusters and its compound leaves three or four feet in length give this
tree an unusual and tropical appearance in northern woods. This
Aralia is now well established in the Arboretum at the northern base
of Hemlock Hill in the rear of the Laurels where it is spreading into
thickets. Indigofera amblyantha, discovered by Wilson in western
China, has been often referred to in these Bulletins, but it is inter-
esting to note that it is still covered with its small rose pink flowers

48

which have been opening during the last three months. Laspedeza for-
mosa, also collected by Wilson in western China, is the handsomest of
the late Autumn-flowering shrubs in the Arboretum. Its arching stems,
light green leaves, and innumerable small pea-shaped rose-colored flow-
ers, make it a beautiful object at this season of the year. Often con-
founded with other species and burdened with an almost hopeless load
of synonyms, Indigofera formosa appears to be little known in gardens.

Autumn Foliage. The Autumn change of color in the trees and
shrubs is later this year than usual and, owing to the dry summer,
will probably be less brilliant than usual. As a general rule the bright
colors appear earlier in the autumn on American than on allied Asiatic
plants, but there are exceptions, of course, to this phenomenon; and
the three plants in the Arboretum which have been most brilliant dur-
ing the last week are Acer ginnala, Evonymus alatus, and Rhododen-
dron {Azalea) japonicum. The Maple is a small, shrubby tree, some-
times thirty or forty feet high with pointed, deeply divided leaves, and
compact clusters of fragrant flowers. A native of eastern Siberia,
where it is common in the neighborhood of Vladivostok, it was one of
the first Siberian plants introduced into the Arboretum from whence
it came from St. Petersburg. The leaves of no American tree assume
more brilliant tones, but this brilliancy lasts only for a few days for
the leaves fall early. Evonymus alatus from Japan is without a
rival in the brilliancy of the deep rose color passing to scarlet of its
autumn foliage. The habit of this shrub is excellent when it has an
opportunity to spread out in the sun but the flowers and fruits are in-
conspicuous. The value of this Burning Bush as a decorative plant is
now appreciated and it is found in many American nurseries, but it
must not be forgotten that it requires a large space in which to de-
velop its greatest beauty. A form of this shrub raised from seeds
collected in Korea by Mr. Jack is handsomer even than the Japanese
form with its larger fruit and even more brilliant autumn foliage. In
their autumn color of old gold the leaves of Rhododendron japoni-
cum are more beautiful than those of any of the Azaleas in the Col-
lection, and this autumn color greatly adds to the ornamental value of
this shrub which when in flower is the handsomest of the Asiatic
Azaleas which are hardy in this climate.

An illustrated guide to the Arboretum containing a map showing the
position of the different groups of plants has been published. It will be
found useful to persons unfamiliar with the Arboretum. Copies of this
guide can be obtained at the Administration Building in the Arbor-
etum, from the Secretary of the Massachusetts Horticultural Society,
300 Massachusetts Avenue, Boston, from The Houghton, Mifflin Com-
pany, 4 Park Street, Boston, and at the office of the Harvard Alumni
Bulletin, 18 Plympton Street, Cambridge. Price, 30 cents.

Complimentary

NEW SERIES VOL. IV

NO. 13

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF

POPULAR INFORMATION

JAMAICA PLAIN, MASS. OCTOBER 18, 1918

The Red or Scarlet Maple (Acer rubrum). The flowers of the Red
Maple are red on some individuals and on others pale yellow, trees
with flowers of these two colors growing together over a large part
of the region inhabited by this tree. On some trees the autumn leaves are
of diiferent shades of red or scarlet and on others clear yellow. If any
reader of these Bulletins has noticed if the autumn color of the leaves
of trees with red flowers is red and that of trees with yellow flowers is
yellow the Arboretum will be glad to hear from him on the subject.
On the left-hand side of the Meadow Road not far from the Jamaica
Plain entrance and opposite the Administration Building there is a Red
Maple with unusually dark crimson autumn leaves. This tree is inter-
esting from the exceptionally beautiful color of the leaves at this sea-
son and from the fact that it is a grafted tree raised to show the pos-
sibility of propagating trees exceptional in the color of their autumn
foliage. This branch of arboriculture has not been much practised,
but when it is realized that the leaves on some individual trees or
shrubs of a species assume more brilliant colors than those of other
individuals of the same species, that this peculiarity is constant from
year to year and that it can be preserved and multiplied by grafting,
there is no reason why a demand for trees with exceptionally beautiful
autumn leaves should not make possible the supply, just as the de-
mand for trees of abnormal habit or with abnormal foliage, like a
Mulberry with pendulous branches or a Beech with purple leaves, has
created the supply. .

49

50

Mountain Ashes. Many of these trees are now growing well in the
Arboretum, and some of them are unusually full of fruit this year and
handsome and interesting objects. Mountain Ashes have leaves divided
into numerous narrow leaflets, compact clusters of white flowers which
are followed by scarlet, yellow, orange-colored, pink or white, usually
globose fruit which varies from a quarter to three-quarters of an inch
in diameter. The best known and most commonly planted of these
trees in the United States is the European Sorbus Aucuparia, the
Rowan tree of Scotland. It is a tree from forty to sixty feet tall, of
pyramidal habit while young, with erect branches which as the tree
grows older spread out into a broad and graceful head. Here the leaves
retain their color until the autumn is far advanced, and during Sep-
tember and October the contrast between the bright green leaves and
the drooping clusters of brilliant red fruit makes this tree an attract-
ive object until the birds strip it of its fruit. This Mountain Ash is
common and widely distributed over the cooler parts of Europe and
was probably early introduced into North America where it has been
much planted in the extreme northern states and in Canada. Several
varieties are recognized. The handsomest of these is the Moravian
Mountain Ash (var. moravica or dulcis) of northern Austria. This is
a tall tree with a smooth stem, leaves with narrower leaflets than
those of the type and larger and sweeter fruit. It is used as food in
central Europe. This Mountain Ash has grown in the Arboretum very
rapidly and promises to become a large tree. Two specimens in the
plantation near the top of Peter’s Hill are now covered with fruit and
are among the handsomest of the small trees in the Arboretum. There
are forms of the Rowan tree with pendulous branches (var. pendula)
and with fastigiate branches (var. fastigiata). There is a form with
yellow fruit and a variety from eastern Europe (var. lanuginosa) the
leaves of which are covered on the upper surface with stiff hairs and
are downy on the lower surface.

Asiatic Mountain Ashes. In recent years a number of these trees
have been brought from eastern Asia to the Arboretum and some of
them promise to be valuable trees here. The Japanese Sorbus com-
mixta was the first of them which was planted here and it has now
been growing in the Arboretum since 1888. There is a tall specimen
of this species on the right-hand side of the path leading to the Shrub
Collection from the Forest Hills Gate. It has smaller flower-clusters
than the European species, the bright red fruit is smaller and its chief
value is in the bright orange and red color of the leaves in autumn.
A much handsomer plant is Sorbus pekinensis, a native of northern
China, which is now well established in the Arboretum. It is a slender
tree with narrow leaflets, compact clusters of flowers and lustrous pink
or yellowish fruit in drooping clusters. The color of the fruit is unusual
among Mountain Ashes. The narrow leaflets give this tree a particu-
larly open and attractive appearance. There are a number of specimens
in the Sorbus Collection in the low ground near the group of Swamp
White Oaks on the Valley Road, but the largest and handsomest spec-

51

imen in the Arboretum is in the nursery plantation near the top of
Peter's Hill. Sorbus Koehneana has flowered and fruited in the Arbor-
etum this year for the first time. It is a shrub now about three feet
high with slender erect stems, small leaves with numerous narrow leaf-
lets, small compact clusters of flowers, and snow-white fruit. It is a
beautiful shrub which when 'better known will become common in gar-
dens. The plants in the Arboretum were raised from seeds collected
by William Purdom in northern Shensi. Sorbus pokuashanensis, so
named because it was discovered on the Pohua Mountains in north-
ern China, is also well established in the Arboretum. The leaflets are
rather broader than those of the Rowan tree, but it has the red fruit
and woolly buds of that species and is not superior to it for general
cultivation. Although they are not as large and shapely trees as some
of the Old World species, the two Mountain Ashes of eastern North
America, Sorbus americana and its variety decora, have no rivals in
this group in the beauty of the great drooping clusters of orange fruit
and in the orange and red tints of their autumn foliage. They are
small trees or large shrubs and are often planted in gardens in Can-
ada, northern Michigan and Minnesota, but unfortunately are still little
known in those of eastern Massachusetts.

Sorbus alnifolia of the section Micromeles of the genus is perhaps
the most satisfactory of the Mountain Ashes with entire leaves which
can be grown here. It is a common Japanese tree and occurs also in
Korea and northern and central China, and sometimes in its native
countries grows to the height of sixty feet. Several specimens have
been growing in the Arboretum since 1893 and are now from twenty
to thirty feet tall. These trees are pyramidal in habit with pale smooth
stems, upright branches which form a broad compact symmetrical
pyramidal head, and dark green leaves three or four inches long, small
white flowers in six- to twelve-flowered clusters, and abundant lustrous
scarlet or scarlet and orange fruit which remains on the branches after
the leaves and until eaten by birds which are fond of the fruit of all
the species of Sorbus. The leaves turn bright clear yellow about the
middle of October and soon fall.

Mountain Ashes thrive only in well-drained rich soil and suffer from
drought and insufficient nourishment. They are particularly liable to
the attacks of the San Jose scale, and in order to secure healthy plants
it is important to spray them late in March or early in April with lime-
sulphur.

The Spindle-tree or Burning Bush. By these names some of the
species of Evonymus are popularly known. Evonymus is a genus of
shrubs or small trees widely distributed over the temperate regions of
the northern hemisphere and more abundant in species in eastern Asia
than in North America or Europe. As a garden plant the species with
deciduous leaves are chiefly valuable for their showy fruits, although
the leaves of some of the Asiatic species become bright colored in
the autumn. The flowers of all the species are inconspicuous. The
fruit is a scarlet, red or whitish capsule, which when it opens displays

52

the seeds enclosed in a bright orange, scarlet or pink fleshy covering
or aril. In the last issue of these Bulletins the autumn beauty of the
Japanese E. alatus was referred to. Another species with leaves con-
spicuous at this season is E. Maackii from the Amoor region of east-
ern Siberia. This is a large, round-topped shrub, the oldest specimen
in the collection being now eight or ten feet tall and twelve or fifteen
feet across the head. The leaves are narrow, pointed at the ends,
drooping, and early in October are dull red on the upper surface and
pale green on the lower surface. The fruit is produced in great quan-
tities and is rose color and half an inch in diameter, and the seeds are
bright orange-scarlet and very lustrous. Although the leaves of the
Japanese E. yeddoensis do not turn as brilliantly as those of some of
the other Asiatic species and fall early, this round-topped shrub is one
of the handsomest of the group when it is covered with its large, rose-
colored capsules which remain on the branches long after the leaves
fall. E. Bungeanus, a small tree from northern China, is an old inhab-
itant of the Arboretum, and every year it is conspicuous when its pale
yellow fruit opens and the rose-colored seeds appear and the narrow
drooping leaves turn pale yellow.

The European species, although they retain their green leaves until
after the scarlet capsules open, are less ornamental plants here than
some of the Asiatic species. The best known of the European species,
E. europaeus, the English Spindle-tree, is a narrow tree which some-
times grows in this country to the height of twenty feet and is hand-
some in the autumn when the dark green leaves make a good back-
ground for the scarlet fruit. There is a variety with white capsules
of no great ornamental value. On a form of this tree raised here from
seeds sent from Hungary the leaves at this season become dark pur-
ple on the upper surface but remain green on the lower surface. The
variety ovata which came to the Arboretum from a German nursery
has broader leaves and larger fruit than the common form and prom-
ises to be a good ornamental plant here. Evonymus latifolius is an-
other European species rather than a tree. The leaves are broader
and the fruit is larger than that of the Spindle-tree. The fruit, unfor-
tunately, is not produced as abundantly as that of most of the other
species. E. atropvpureus, the Burning Bush of the United States, is
a small tree which grows naturally from western New York to Montana
and to Florida and Texas. The leaves turn yellow in the autumn some
time before the crimson fruit falls. This tree is hardy in Massachu-
setts but has never taken very kindly to cultivation in the Arboretum.
The Strawberry Bush, E. americanus, is a straggling shrub with slen-
der semiprostrate stems and fruit covered with prickles. It is a com-
mon plant in the United States from New York southward, but has
never found itself really at home in the Arboretum. E. ovatus is
another American species with prickly and tuberculate fruit, and is
a low shrub with prostrate stems. This species is valuable for covering
the ground in the shade of larger plants where it grows vigorously;
when exposed to the full sun it suffers here from the exposure.

COMPLIMENTARY

NEW SERIES VOL. IV

NO. 14

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF

POPULAR INFORMATION

JAMAICA PLAIN. MASS. OCTOBER 25, 1918

Hawthorns handsome in the autumn. Some of the American Haw-
thorns are more beautiful when their fruits ripen in the autumn than
they are when the white flowers cover the branches in the spring and
early summer, and there are great horticultural possibilities in these
plants which are particularly valuable in those parts of the country
where the soil is impregnated with lime. Indeed American Hawthorns,
although they do not require lime, are lime-loving plants, and the
largest number of species and the handsomest plants are found where
lime abounds. In the parks of cities like Chicago, St. Louis and
Pittsburg, where the smoke of bituminous coal is fatal to many plants,
it has been found that American Hawthorns grow better than most
trees and shrubs. It is impossible in one of these Bulletins to do more
than mention briefly a few species which are exceptionally beautiful
at this season and have shown themselves v/ell suited for general cul-
tivation.

Crataegus arkansana. This tree is a native of the valley of the
White River in central Arkansas and was first raised in the Arboretum
in 1880. It belongs to the Modes Group of the genus which is distin-
guished by its large usually tomentose leaves, large flowers and large
scarlet, or rarely yellow, edible fruit. Like the other species of the
group, C. arkansana is a tree which in the deep rich soil of Arkansas
bottom-lands sometimes grows to the height of forty feet. The fruit of
many of the species of this group, like C. Arnoldiana and C. mollis,
ripens in August and September and soon falls; that of C. arkansana
does not ripen until the middle of October when the leaves are still green

53

54

and remains on the branches until the end of November. This late
ripening of the fruit after that of the other large-fruited species has
disappeared makes C. arkansana one of the interesting and valuable
species. The largest plant in the Arboretum is on the left-hand side
of the South Street entrance just outside the gate where it is growing
with a plant of C. suhmollis, a species of the same group, which loses
its fruit early in September.

Nearly all the species of the Tomentosae Group, named for one of
the species, C. tomentosa, and distinguished by the longitudinal cavi-
ties on the inner faces of the nutlets, have lustrous and showy fruits
with the exception of C. tomentosa itself and some of the species
closely related to it. Crataegus prunifolia is one of the handsome
plants of this group. It is a large, compact, round-topped shrub or
small tree with brilliant scarlet fruit and lustrous leaves which turn
bright orange and scarlet in the middle of October. Although this
plant was cultivated in England more than a hundred years ago and is
certainly a native of North America, it is still unknown in this country
as a wild plant. For at least a century botanists have considered C.
prunifolia a variety of the Cockspur Thorn (C. Crus-galli) because the
leaves somewhat resemble in shape the leaves of that tree, no one
apparently having taken the trouble to examine the nutlets. Crataegus
succulenta is another beautiful member of the Tomentosae Group with
drooping clusters of scarlet fruits which remain hard until late in the
autumn and then suddenly increase in size and become soft, succulent
and translucent. It is a small tree not rare in the region from Massa-
chusetts to Illinois and one of the handsomest species of the group.
Crataegus macracantha, another species of this group, is remarkable for
the long stout spines which thickly cover the branches and which
would make it a good hedge plant. This species is particularly showy
when the flowers in large, round-topped compact clusters open in June,
but the fruit is less beautiful than that of C. succulenta. Species of
this group are abundant in the neighborhood of Toronto and other
parts of southern Ontario, and some of these Canadian plants, although
they are not old enough yet to produce fruit here, promise to become
important additions to the collection.

Crataegus nitida from the bottom-lands of the Mississippi River in
Illinois near St. Louis, a member of a southern group (Virides), is, as
has often been said in these Bulletins, one of the handsomest of the
American species cultivated in the Arboretum. It is a wide-branched,
flat-topped tree sometimes thirty feet high with narrow, dark green
shining leaves which late in October assume the most brilliant shades
of orange and scarlet, rather small flowers in numerous crowded clus-
ters, and drooping, oblong, brick-red fruits marked by small white
dots. Very diiferent in appearance is another tree from the neighbor-
hood of St. Louis, C. coccinioides. This has broad, deeply-lobed leaves
which also become orange and scarlet late in October, but the flowers
are an inch in diameter with twenty stamens and deep rose-colored an-
thers. The flowers are arranged in compact from five- to seven-flowered
clusters, and are followed by subglobose, dark crimson, lustrous fruits

55

marked by large pale dots and nearly an inch long, and rather longer
than broad. The fruit ripens about the middle of October as the leaves
turn color and does not entirely fall before December. Another mem-
ber of the same group as the last C. durobrivensis (Dilatatae), the
Rochester Thorn, is valuable for the winter garden because the dark
crimson fruit, which is nearly three-quarters of an inch in diameter,
remains on the branches uninjured by frost until midwinter. It is a
large shrub with flowers an inch in diameter in many-flowered clusters.

Crataegus pruinosa. This is the type of another northern group
distinguished by its thick leaves usually broad at the base with long
slender stems, large flowers and large fruit often broader than high,
frequently angled, green or red covered with a pale bloom, surmounted
by a prominent calyx raised on a tube, and hard dry flesh. Many of
the species are handsome in spring and autumn and the type of the
group, C. pruinosa, especially deserves the attention of planters. It
is a small tree which grows naturally from southern Vermont to Mis-
souri and along the foothills of the Appalachian Mountains. It has
thick, blue-green leaves; the flowers are sometimes an inch in diame-
ter and conspicuous from the twenty large, deep, rose-colored anthers,
and the fruit, which is arranged in broad drooping clusters, is subglob-
ose, rather more than half an inch in diameter, apple green until late
in autumn, when it becomes dark purple red and very lustrous.

Dwarf Hawthorns. From the middle to the end of October there is
not a more interesting group of small shrubs in the Arboretum than that
of the species of Crataegus in the Intricatae Group which is arranged
on the lower side of the road at the eastern base of Peter’s Hill next
to the Crabapple Collection. These shrubs are confined to the northern
United States and Canada, and are perhaps more numerous in Penn-
sylvania and Michigan than in other parts of the country. They bloom
later than most of the American Hawthorns, the flowers of all of them
are large and conspicuous with yellow, rose-colored or pink anthers.
The fruit ripens late and is scarlet, red, orange, yellow or russet, and
its beauty is increased by the brilliant colors of the leaves at the time
it ripens. A large number of these plants are now in the collection.
One of the handsomest this year is C. cuprea with scarlet foliage and
russet or copper-colored fruit. This little shrub was first detected in
a vacant lot in the city of Wilmington, Delaware, and is not known
to grow naturally beyond the limits of that city. C. Delossii, found
growing several years ago by the side of a road near Toronto, is un-
usually full of its orange and red fruit this autumn. This species dif-
fers from the others of the group in the large number of fruits (ten
to fifteen) compactly arranged in dense clusters. The autumn leaves
are green and yellow. Other species of this group deserving attention
are C. infera from the neighborhood of Sellersville, Bucks County,
Pennsylvania, with orange-red fruit and brilliant orange and red autumn
leaves; C. fructuosa, a shrub five or six feet talKwhich has only been
found on the Serpentine Ridge near West Chester, Pennsylvania, with
deep orange-red fruit in small erect clusters, and dark red-purple
autumn leaves; and C. modesta, a little shrub often not more than

56

twelve or eighteen inches high, first noticed on a hill near Rutland,
Vermont, but now known to grow in many places in southern New
England and to range into eastern Pennsylvania, and conspicuous in
the autumn with its bright scarlet leaves and green, yellow or orange
and red fruits. Two species of the group in the southern Appalachian
Mountain region, C. Buckleyi and C. Boyntonii, are small trees and
have grown in the Arboretum into dense pyramids now eight or ten feet
tall, and still covered with dark green leaves which later turn to
shades of orange and scarlet.

The Tulip-tree (Liriodendron) is unfortunately not a native of eastern
Massachusetts, although it occurs in the western part of the state and
in Rhode Island. It is perfectly hardy here, and has grown to a large
size in the neighborhood of Boston. It is therefore surprising that this
tree is not more generally planted here for the American Liriodendron
is one of the most magnificent trees of the northern hemisphere, grow-
ing as it does when all the conditions of soil and climate favor it, as
in the rich “coves” of the southern Appalachian Mountains, to the
height of two hundred feet and forming a trunk eight or ten feet in
diameter and free of branches for half its height. The tulip-shaped
flowers and the leaves, which are of unusual shape, are beautiful and
interesting, but attention is now called to this tree on account of the
beautiful color of the autumn foliage. This when the leaves first lose
their green color is bright clear yellow but later as they begin to fall
becomes darker and the color of old gold. In October in those parts
of the country like Delaware County in eastern Pennsylvania, and on
the slopes of the southern mountains where the Tulip-tree forms a con-
siderable part of the forest and often raises its head high above its
humbler companions, its spire-like bright golden crowns produce a
beauty which can be found in no other part of the world. The Chin-
ese Tulip-tree of recent discovery has not proved hardy in the Arbor-
etum. It is a much smaller tree than the American species with
smaller flowers but larger and handsomer leaves.

Pyrus Calleryana, This Pear-tree, which was raised here from seeds
collected by Wilson in western China, has less beautiful flowers than
many other Pear-trees, and the russet-colored fruit is not more than
half an inch long. It may, however, prove to be one of the most val-
uable plants introduced into the United States by the Arboretum, for
it is now believed by American pomologists that it will prove to be a
blight-resisting stock on which to graft the varieties of garden pears.
The Arboretum trees appear to be the only ones in the United States
large enough to flower and this year they have produced a good crop
of fruit which will be sent to the Department of Agriculture for dis-
tribution.

Complimentary

NEW SERIES VOL. IV

NO. 15

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF

POPULAR INFORMATION

JAMAICA PLAIN, MASS. OCTOBER 30. 1918

Some late October colors in the Arboretum. Now that the leaves
of the Sweet Gum (Nyssa) and the Liquidambar have fallen the most
brilliantly colored tree here is the Scarlet Oak {Quercus coccinea) which
has no rival among the northern Oaks in the bright scarlet of its shin-
ing deeply divided leaves. We are here near the northern limits of
the range of this tree and it is not very common in the neighborhood
of Boston. In Plymouth County and in some parts of Cape Cod it is a
prevailing tree, and to those who love the woods in autumn that part
of the state is well worth a visit this week or next. The leaves of
only one other Oak turn in the autumn to more brilliant shades of
scarlet and that is the Turkey Oak (Q. Catesbaei) of the southern
states, a smaller tree than the Scarlet Oak but with larger and often
more lustrous leaves. Persons who like most northerners know the
coast region of South Carolina and Georgia and the Florida peninsula
only in late winter or in spring have little idea of the splendor of the
color which the Turkey Oak gives that part of the country at the end
of November. The leaves of some trees of the Pin Oak (Q. palustris)
are turning scarlet or scarlet and yellow, and those of other trees are
still nearly green, scarlet or nearly green leaves often occurring on
the same branch. The Pin Oak is a handsome tree at this time of the
year although it is less brilliant and conspicuous than the Scarlet Oak.
This is true, too, of the Red Oak, the autumn leaves of which vary
on different individuals from yellow to dark red, bright red, red and
yellow, and brown. On the trees of the White Oak Group the hand-
somest autumn foliage is found on the White Oak itself (Q. alba). The
leaves of this tree turn later than those of most Oaks and when in

57

58

perfection are often of a deep rich vinous red color. The other Amer-
ican White Oaks which are hardy here, the Bur Oak (Q. macrocarpa),
the Swamp White Oak (Q. bicolor), the southern Overcup Oak (Q. lyr-
ata), the Post Oak (Q. minor) and the three Chestnut Oaks (Q. mon-
tana, Q. Muehlenbergii and Q. prinoides) turn yellow in part or en-
tirely in the autumn, and from most of these the leaves fall earlier
than those of Q. alba. Among the White Oaks the leaves of which
turn yellow in the autumn a single individual of the Swamp White Oak
with large, bright scarlet autumn leaves is a remarkable exception to
the general autumn color scheme of these trees. This is one of the
most remarkable and interesting trees in the Arboretum collection of
Oaks. It is growing in the mixed plantation by the road at the sum-
mit of Peter’s Hill and was probably raised in the Arboretum, although
unfortunately no record of its origin has been kept.

Among the smaller trees with scarlet or crimson autumn foliage none
is more beautiful now than the so-called Flowering Dogwood {Cornus
Horida) which is unusually brilliant this year in its shades of crimson,
scarlet and green. Its autumn beauty is increased by the contrast of
of the color on the upper and lower surface of the leaves for only the
upper surface changes color, the lower surface retaining the pale some
times nearly white color of the summer. Another tree with leaves red
or scarlet on the upper surface and pale on the lower surface, Acer
nikkoense, is well worth the attention of persons interested in the
autumn color of tree leaves. Acer nikkoense is a native of the moun-
tain forests of central Japan and is one of the species with compound
leaves related to the Ash-leaved Maple or Box Elder {Acer Negundo) of
the United States. There are several good specimens of this handsome
tree in the mixed plantation on the road near the top of Peter’s Hill
where the leaves of these trees are now beginning to change color.
Another small Maple from northern Japan, A. Sieboldianum, has been
conspicuous this year in the intense scarlet of its leaves which are now
beginning to fall. The best plants in the Arboretum of this tree are
also in the mixed plantation on Peter’s Hill.

Several plants are interesting now from the dark purple color of
their autumn leaves. Among these is a variety of Prunus serrulata
(var. pubescens), a large pink-flowered Cherry raised from seeds col-
lected by Wilson in western China. One of the Japanese species of
Stuartia (S. pseudocamellia) has autumn leaves even darker than those
of this Cherry. This Stuartia is a hardy little tree with pale smooth
bark exfoliating in large thin scales and white flowers which look like
those of a single-flowered Camellia, and open in summer. There are good
specimens of this tree on the left-hand side of Azalea Path. Akebia
quinata, the Japanese species with leaves composed of five leaflets and
small dark purple flowers, is well known in American gardens. The
leaves fall late in the autumn without having changed color. The
other Japanese species, A. lohata, is less well known in this country.
From the other species it differs chiefly in the three, not five, rather
larger leaflets which turn late in the autumn to a handsome dark bronze
color. In this country the Akebias rarely produce fruit, which re-
sembles in shape a short thick banana and is pale violet in color. It

59

contains many small seeds imbedded in sweet juicy insipid pulp of
which the Japanese appear fond, as the fruit of A. lobata is found in
September in great quantities in the markets of the towns of northern
Japan.

Vaccinium Carlesii, although discovered in Korea only a few years
ago, is fast becoming a popular garden plant in the United States
where it is admired for its compact clusters of fragrant white flowers
which open from rose-colored buds, closed buds and open flowers oc-
curring together in the same cluster. The value of this handsome little
shrub is increased by the autumn color of the leaves which are now
dark bronze purple. Little has been known of this plant in its native
country but Mr. Wilson, who has passed the last two summers in
Korea, writes of it, “This is a maritime species fond of cliffs and rocky
soil; it grows in localities rather remote one from the other and is no-
where common."

Witch Hazels (Hamamelis). The different species of this genus add
to the interest of the Arboretum in the autumn and winter by the
colors of their leaves and the opening of their flowers. The first spe-
cies to change its color is Hamamelis japonica, one of the winter-
flowering species. The leaves of the other Witch Hazels turn bright
clear yellow in the autumn, but the autumn color of the leaves of the
Japanese species is scarlet and orange. During a week early in Octo-
ber the leaves were brilliant but they have now fallen. The pale clear
yellow autumn leaves of the eastern American species {H. virginiana)
have nearly all fallen from the branches which are now covered with
pale yellow flowers. The leaves of the other American species {H,
vernalis) are still green on some individuals and on others are begin-
ning to turn yellow. Toward the end of December or early in January
this shrub, which grows naturally along small streams in southern
Missouri, will be covered with flowers. The dull blue-green leaves of
the Chinese Hamamelis mollis are still as green as they were in mid-
summer but later they will turn to a beautiful shade of pale yellow.
The flowers of this remarkable plant open usually late in January or
early in February and are larger and more conspicuous than those of
the American or Japanese species. No winter garden can be complete
without these winter-flowering shrubs.

Enkianthus. The autumn colors of the leaves of the four Japanese
species of this genus of the Heath Family which are established in the
Arboretum have been remarkably brilliant during October and it is un-
fortunate that these handsome plants are not more generally found in
gardens in those parts of the United States where the presence of lime
does not make the cultivation of plants of the Heath family impossible.
All the species have bell-shaped flowers arranged in gracefully droop-
ing clusters, but their greatest beauty is in the color of their autumn
leaves. This is scarlet, crimson or deep wine color on the different
species. The deep crimson or scarlet colors which the leaves of E.
perulatus or japonicus assume make this the showiest of the species
at this season and one of the most popular plants in Japan where it is
usually cut into dense round balls. In the Arboretum this shrub has

60

not produced seeds and it has remained rarer in this country even than
the other species. The large group of these plants on the right-hand
side of Azalea Path shows the habit and autumn coloring of the leaves
of the different species.

Blueberries in autumn. The leaves of all the deciduous-leaved Blue-
berries asd Huckleberries turn bright scarlet late in the autumn, and
as a ground cover in native woods there are no more beautiful plants
than the three dwarf Blueberries of the eastern states, Vaccimum
pennsylvanicum, V. canadense, V. vacillans. In the whole northern
hemisphere there is hardly a shrub which equals the Highbush Blue-
berry, V. corymbosum, for the decoration of New England gardens.
The white flowers in drooping clusters are beautiful, the blue-black
fruits are even more beautiful than the flowers, but it is in the late
autumn that this shrub is most valuable as a garden or woodside orna-
ment for the crimson of its autumn leaves is not surpassed in intensity
by that of any other shrub. There is considerable variety in the shades
of color in the leaves of different individuals, and on some plants crim-
son and green leaves are found together. There are a number of plants
of this Blueberry on the sides of Azalea Path near its entrance from
Bussey Hill Road which show the variety of autumn leaf color of this
Blueberry.

Forsylhias. The leaves of all the forsythias usually fall, like those
of the garden Lilacs, without having greatly changed color, but occa-
sional plants of F. suspenaa var. Fortunii occur on which the upper
surface of the leaves turn bronze purple while the lower surface retains
its summer color. Such plants are more valuable than those with green
autumn leaves and should be propagated.

Barberries in late October. The leaves of many of the Barberries
in the Arboretum collection have now turned crimson, scarlet, or scarlet
and orange, making these plants which are now covered with scarlet
fruit conspicuous. Of the species closely related to the common Bar-
berry {Berberis vulgaris) the handsomest perhaps is the Japanese Ber-
beris Regelii, a large shrub with large pale flowers, large fruit and
leaves which turn orange and scarlet. Although still rare here, this
plant was brought to the United States more than fifty years ago and
was long cultivated in the Parsons’ Nursery on Long Island as Berberis
Hakkadate. The Chinese B. diaphana is probably now the handsomest
of the species with dark crimson autumn foliage. This is a low, round-
topped shrub broader than high, with large solitary flowers which rarely
produces fruit here. The only objection to it is that the leaves unfold
so late that the plants appear dead when other Barberries are covered
with nearly fully grown leaves. Among the new Chinese species the
most beautiful Barberry in the autumn is B. circumserrata, a small
round-topped shrub with large solitary flowers and leaves which in an-
other week will be of as brilliant shades of scarlet as those of any
plant in the Arboretum. Other species which are particularly attractive
this week are B. koreana, B. lucida, B. amurenais, and B. dictyophylla.

COMPLIMENTARY

NEW SERIES VOL IV

NO. 16

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF

POPULAR INFORMATION

JAMAICA PLAIN, MASS. NOVEMBER 7, 1918

In the early numbers of the present volume of the Bulletin the ef-
fects of the severe winter on many plants in the Arboretum was dis-
cussed. Several plants which were then believed to be dead produced
leaves in June and some are now apparently in good health; others
which were only killed to the ground have grown again from the
stumps and the damage by the winter has been less severe than it was
believed to be in May.

Oaks. In the third week of May the Willow Oak {Quercus Phellos),
the southern Overcup Oak (Q. lyrata), the Spanish or Red Oak of
the south (Q. rubra or falcata), the so-called Turkey Oak of eastern
Europe {Q. Cerris), the hybrid Q. heterophylla from the middle states,
and a little Oak from Stone Mountain, Georgia {Q. georgiana), appeared
to be dead. Six weeks later they were covered with healthy leaves,
with the exception of the last which after a hard struggle for life
finally died. Fortunately this species is represented in the Arboretum
by a healthy young specimen which was not injured by the winter. A
fine specimen of the weeping form of one of the European Oaks {Q.
Robur var. pendula), which appeared in the spring to have been ruined,
escaped with the loss of a single branch. A vigorous species of the
native Black Oak (Q. velutina), one of the common trees in Massachu-
setts, growing with others in the Oak collection, was killed, showing
that exceptional cold like that of the past winter may kill even
the hardiest native trees. This is shown, too, in the fact that two
trees of the Sour Gum {Nyssa sylvatica) were killed in the group by the
little pond near the junction of the Meadow and the Bussey Hill Roads.

61

62

Ashes. The three trees of Fraxinus syriaca, often cultivated as
F. sogdiana, which have been uninjured in the Arboretum for thirty-
eight years and have frequently flowered and ripened their fruit here,
were killed to the ground but have now sent up a few feeble shoots
from the roots. The flowering Ash so called, {Fraxinus Ornus) of
southeastern Europe, which has suffered before in the Arboretum but
flowered here in the spring of 1917, is now represented by a few weak
stump shoots which did not appear until September. Fraxinus Paxi-
ana, one of the new introductions from western China, was killed in
the Ash collection, but was not injured in the Peter’s Hill Nursery.

The Liquidambar and other trees. The North American Liquidambar
opened its leaf-buds so late that by the middle of May the trees looked
as if they were hopelessly injured. Later they entirely recovered, and
in October the leaves of this beautiful tree have not before been more
brilliantly colored here. A single plant of the Chinese Liquidambar
formosana is still living in the Peter’s Hill Nursery; it is, however,
only a bush for it is more or less injured every winter, and it is prob-
able that this tree will never flourish in the United States except in
some of the Gulf and Pacific coast states. Catalpa Bungei has not
suffered before in the Arboretum but many branches on all the trees
were killed by the winter, and one of the two specimens in the Catalpa
collection on the hill above the Lilacs was killed to the ground but has
now sent up a number of shoots from the roots. The condition of the
three Persimmon trees {Diospyros virginiana) in the group on the right-
hand side near the lower end of the Bussey Hill Road illustrates the
fact that some individuals of a species can resist cold better than
other individuals of the same species. These three trees were of the
same origin and the same age; two are uninjured and the third is
now represented by a few weak suckers from the roots.

Various shrubs injured by the winter. Although it was believed in
May that the Arboretum had lost a number of species by the excessive
cold of the winter, the actual loss has not been as serious as it then
appeared. All the plants, however, of the Japanese Ilex crenata were
killed. These plants have been growing in the Arboretum for twenty-
five years and had never suffered in earlier winters more than the loss
of a few leaves. This Holly was believed therefore to be one of the
few broad-leaved evergreens which could be safely used in northern
gardens. Plants of the Inkberry {Ilex glabra), a common Atlantic and
Gulf coast shrub from New Hampshire to Texas and one of the hand-
somest and hardiest of the broad-leaved evergreen shrubs which can
be grown here, lost for the first time in the Arboretum a large part
of their leaves and a few branches during the winter. The plants soon
recovered, however, and are now as thickly clothed with leaves as they
were a year ago. The largest plants of Ilex opaca, another native of
the Massachusetts coast region, were killed outright, but smaller plants,
although they lost most of their leaves, are still alive. One of the
new Chinese species of Magnolia {M. Wilsonii), Daphne genkwa and
Lonicera Delavayi appear to be the only species of recent introduction
which have been actually killed. All the plants of Sophora viciifolia
appeared to be dead until June when the leaves began to unfold. None

63

of the plants flowered but they are all in good condition. All the plants
of the new Chinese genus of the Witch Hazel Family {Sinowilsonii)
appeared to be uninjured in May but many of the branches died after
the leaves were fully grown, and although these plants may recover
their present condition is not satisfactory.

Evergreen Barberries. It is a satisfaction to be able to report that
the four species of evergreen Barberries from western China in the
collection, Berberis Julianae, B. Sargentiana, B. Gagnepainii and B.
verruculosa, are now in good condition, although the leaves of all but
the last species were killed and many of those of B. verruculosa were
injured. It may be expected therefore that these beautiful plants may
continue to live in eastern Massachusetts if suitable positions can be
found for them.

Corylopsis. The two species of western China which were covered
with flowers in the spring of 1917, C, Willmottiae and C. Veitchiana^
were killed to the ground by the cold of the winter and are now rep-
resented by feeble stump-shoots, and it is doubtful if these plants can
be sucessfully and permanently grown in this climate. The Japanese
C. pauciflora and C. spicata, which lost their flower-buds and some
branches have not looked well through the summer but are recovering.
Another Japanese species, C. Gotoana, which was uninjured in bud and
leaf, seems destined to become a popular garden plant in the northern
states.

Several other shrubs which were injured by the winter and in May
and June gave little promise of recovery, are now alive and will prob-
ably entirely recover. Among them is a plant of the Japanese Lindera
obtusiloba which, although it has been growing in the Arboretum for
twenty-five years, is still one of the rarest plants in the collection as
it has not borne seeds and has proved difficult to propagate. This plant
is most beautiful in the autumn when the leaves during the first week
in November are the color of gold. Another Japanese Benzoin, B.
sericea, which was injured by the winter will probably recover, although
this plant has suffered in less severe winters and will probably never
be valuable in this climate. The two Dipeltas, a Chinese genus related
to Weigela, which were killed to the ground have produced shoots from
the roots. These plants, although they have flowered sparingly in the
Arboretum, have suffered from cold before and it is doubtful if they
can be successfully grown in Massachusetts. Rhus Potaninii, Cornus
paucinerviSy Salix Bockii, Osmaronia cerasiformis and Ceanothus
Wrightii have recovered, as was predicted in the Bulletin issued on
the 16th of May. The most important of these for the garden is Cor-
nus paucinervis for it flowers here late in July when comparatively few
shrubs are in bloom. It is a narrow shrub with numerous upright stems
five or six feet high, small narrow pointed leaves with only two or
three pairs of veins, small flat clusters of white flowers and small black
shining fruits. If this plant proves as hardy in eastern Massachusetts
as it has at Rochester, New York, it will be one of the most valuable
of Wilson’s introductions from western China. Coluteas bloom on the
branches of the year and all the species, although they had been killed

64

to the ground were later as full of flowers and fruits as they were in
ordinary seasons.

The following plants believed to be dead in the spring are still alive,
although it is doubtful if they can be permanantly successful in this
climate: Stachyurus chinensis, Staphylea holocarpa, Poliothyrsis sinen-
sis, and Fortunearia sinensis. The Staphylea, which Wilson believed
to be one of the handsomest of the small trees which he saw in China,
has never done well in the Arboretum, and although there is still life
in some of the small plants it is doubtful if it ever flowers here. Vibur-
num ovatifolium, which was reported in May to have been killed, has
grown again from the roots, and all the Chinese Viburnums with decidu-
ous leaves are now in good condition. The two evergreen species which
live here, V. rhytidophyllum and V. buddleifolium, lost their leaves
from the cold but are now covered with a new growth and look as well
as they usually look here at this season of the year. They are better
suited, however, for a milder climate than that of New England. Loni-
cera Henryi, a Chinese species with twining stems and evergreen foli-
age, was killed to the ground but is growing again. This beautiful plant
flowered for several years in the Arboretum and was believed to be per-
fectly hardy and an important addition to the small number of broad-
leaved evergreens which can be successfully grown in the northern
states.

Broad-leaved Evergreens. The colors which the leaves of a few of
these assume in the autumn add greatly to the beauty of these plants
in November. The most conspicuous change of leaf color on any of
these plants is on the Rocky Mountain Mahonia (or Berberis) repens.
From light bluish green the leaves turn to pale violet color in the au-
tumn. This is one of the handsomest and hardiest evergreen plants
which can be used here to cover the ground under larger plants; it
grows only a few inches high, spreads rapidly by underground stems,
and the bright yellow flowers are large and conspicuous. It is unfor-
tunate that eastern nurserymen have not yet learned the value of this
plant. The small dark green leaves of the Box Huckleberry {Gaylus-
sacia brachycera) become in the autumn deeply tinged with red when
the plant is fully exposed to the sun, and the leaves of Pachystima
Canbyi are more or less tinged with violet. These are two of the
rarest plants in the United States, being known now only in two locali-
ties, the first in Pennsylvania and the other in West Virginia where the
Pachystima has not been seen, however, for nearly fifty years. The
leaves of Leucothoe Catesbaei often turn deep bronze color in the
autumn. This plant which has always been considered hardy in east-
ern Massachusetts, suffered seriously during the winter. Most of the
plants lost the ends of their branches and their leaves, and many
were killed outright in a particularly favorable position for this shrub
where it had been established for nearly twenty years. The Rhodo-
edndrons are in good condition and generally well furnished with fiow-
er-buds, and the Laurels {Kalmia latifolia) have not before in the
Arboretum given such promise of abundant bloom.

Complimentary

NEW SERIES VOL IV

NO. 17

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF

POPULAR INFORMATION

JAMAICA PLAIN, MASS. NOVEMBER 11, 1918

In the Pinetum. The collection of cone-bearing trees and shrubs is
of special interest this autumn as during the past twelve months it
has had to endure such severe weather conditions that plants which
are now in good condition should be able to successfully support
any extremes of heat, cold and dryness which they are likely to meet
with in Massachusetts. In discussing the possibility of cultivating
conifers in the northeastern United States it must be remembered that
at its best this is not a favorable climate for these trees. There are
only a few indigenous species here in New England, and all the exotic
species which can be grown here grow better in other parts of the
world. This is the region for trees and shrubs which lose their leaves
in autumn and the man who wants to plant successfully and perma-
nently here must use these plants, and not conifers or broad-leaved
evergreens, unless he is prepared to suffer many disappointments. It
is the business of a scientific establishment like the Arboretum to ex-
periment with all plants which, judged by the region where they grow
naturally, have any chance of success and to report failures as well as
successes. Enough is now known of the habitat and climatic condi-
tions necessary for the conifers of the world to make it possible to
say that none of these trees which grow in any part of the world
south of the equator can grow here. It is now known that none of
the conifers of the southern United States, Mexico, Central America
and the West Indies can be grown in the north. This is true, too, of
the species of southern Europe, northern Africa, southern India, south-
western China, Formosa and the southern islands of the Japanese em-
pire. Of the conifers of the Pacific coast of North America only a
few can grow at all in the east. The planter of conifers therefore in the

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66

New England, middle and middle western states must make his selec-
tion from native species, and from the species of northern Japan,
Korea, northern China, Siberia, the Caucasus and eastern and northern
Europe, That is, the largest and some of the handsomest and most
interesting trees in the world cannot be successfully grov/n in the United
States except in the south, and in western Washington, Oregon and
California where the climate is better suited to the successful culti-
vation of conifers perhaps than that of any other part of the world,
with the exception possibly of New Zealand where conifers from all
parts of the world have grown with astonishing rapidity and vigor, and
in the case of some species to a larger size than individuals of the
species attain in their native lands.

In spite of the unusual and prolonged cold of the winter which fol-
lowed a dry summer, the cold spring and the drought which lasted
from April to September the Arboretum conifers are not in bad condi-
tion, and it is now possible to discuss with more confidence the value
of many exotic species than it has been before. Only one species has
been entirely lost from the effects of the severe winter. This is the
blue-leaved form of Cedrus atlantica, a native of the mountains of
Algeria, There was only one specimen in the Arboretum where it has
been growing for many years in a sheltered position in the middle of
a Pine grove. This beautiful tree sometimes grows fairly well south
of Cape Cod, but there is little hope 'that it will live for more than a
few years at a time in Massachusetts,

Some of the species of the northeastern states have suffered more
than any of the exotic species, and several plants of the Red Spruce
{Picea rubra) were killed or so badly injured that it was necessary to
destroy them. If any coniferous tree should be hardy here it is the
Red Spruce which grows on some of the high mountains of New Eng-
land and close to the seashore of Maine and New Hampshire where it
is fully exposed to the gales from the Atlantic, The Red Spruce,
although there are now a number of healthy individuals in the Arbor-
etum, does not take very kindly to cultivation and always grows slowly.
Another eastern American tree, the short-leaved Pine {Pinus echinata)
was injured by the winter. This tree finds its northern home on
Staten Island, New York, and there have been a number of trees
raised from seeds collected at this northern station growing in the Ar-
boretum for twenty years. These all lost their leaves and several were
killed; the others produced new leaves in June and now look nearly as
well as ever. One specimen of this Pine raised here in 1879 from
Missouri seeds also lost all its leaves but is now in comparatively as
good health as it was a year ago. Several plants of the White Cedar
of the eastern states {Chamaecyparis thyoides) lost their tops and were
a good deal injured by the winter although none were killed. This
plant has not taken kindly to the conditions the Arboretum affords it,
but it is surprising that it is not more hardy here, as within twenty
miles of Boston there are hundreds of acres of low ground covered
with forests of this tree.

Cedar of Lebanon. The Cedars of Lebanon raised here from seeds
gathered on the Anti-Taurus, which have been growing in the Arbor-
etum for sixteen years and which have not before been injured by heat

67

or cold, in early spring lost all their leaves which had been killed by
the excessive cold of the winter; they soon put out a new growth, how-
ever, and although the branches are now less densely covered with
foliage than in other years the trees are in good health. Among the
Spruces and Firs the Grecian and Roumanian form of Abies cephalonica
(var. Apollinis) suffered the most, and although the plants are still alive
they can never grow into good trees. Some small plants of Abies
cephalonica were killed, but the large plants of this Fir in the collection
are in good condition, although this tree was badly injured in other
collections in Massachusetts and New York. Abies cilicica, which has
been for many years considered one of the hardiest and handsomest
of the Firs which can be grov^n in the northeastern states, has suffered
seriously in other collections, but in the Arboretum it was little injured
by the winter and is now in good condition. Abies amabilis from the
Cascade mountains of Oregon, although always a slow-growing, shabby
looking tree in cultivation, lost a good many leaves in the spring but
is now in its usual health. Abies grandis from the northwest coast,
planted in sheltered and exceptionally favorable positions, is uninjured,
but for general use in Nev/ England this handsome tree should not be
depended on. The Sugar Pine of the California Sierras {Finns Lam-
bertiana) and the Chinese White Pine (P. Armandi) lost a good many
leaves but now look as well as usual. The Japanese Black Pine (P,
Thunbergii) suffered more in the loss of its leaves, but the buds were
uninjured and the trees, although somewhat disfigured, are recovering.

Among the long established trees here which are not native in New
England and which show no evidence of having just passed through the
most serious experience of their lives, and may therefore be considered
suitable for cultivation in the northern states, are all the forms of the
Norway Spruce {Picea Abies), the Balkan Spruce (P. omorica), the Cau-
casian Spruce (P. orientalis), the Siberian Picea obovata, Picea Schrenk-
iana from Chinese Turkestan, all the Japanese species, and the spe-
cies of the Rocky Mountains P. pungens, P. Engelmannii and the west-
ern form of P. canadensis. The Firs not already mentioned which
have not been injured are the Rocky Mountain form of Abies concolor,
which is the most satisfactory of all Firs in the northeastern states,
the Caucasian Abies Nordmaniana, the Japanese A. homolepis, (or
brachyphylla) and A. Veitchii. Like the eastern American Balsam
Fir {A. balsamea), the Rocky Mountain A. lasiocarpa and the Fir of
central Siberia {A. sibirica) are perfectly hardy here, but are short-
lived shabby trees in cultivation, and are not worth planting in east-
ern North America. The Korean A. holophylla was first raised at the
Arboretum twelve years ago and it is still one of the rarest of all coni-
fers in cultivation. Fortunately Wilson sent from Korea a year ago
a supply of seeds of this tree; these germinated well and there are
now many seedlings in this country and Europe. The twelve-year-old
plant has grown well in the Arboretum; it has not suffered from cold
or heat and promises to be a good tree here. The Douglas Spruce
(Pseudotsuga mucronata) raised from seeds gathered in Colorado, has
been growing in eastern Massachusetts for nearly fifty years and prom-
ises to live long here and grow to a large size. Numerous specimens
of the Carolina Hemlock {Tsuga caroliniana) have been uninjured by
the cold and drought of the year. This is one of the handsomest of

68

all cone-bearing trees which can be grown in this part of the country.
One plant of the Japanese Tsuga densifiora was killed during the
winter, but several others were uninjured. Small plants of the Jap-
anese T. Sieboldiana have lived in an exceptionally sheltered position,
but there is little hope that this beautiful tree, which is more southern
in its range than the other Japanese Hemlock will ever live long in
Massachusetts. A small plant of the Hemlock of the Northwest coast
of North America {T. heterophylla), the largest and handsomest of all
Hemlock trees, was uninjured in a sheltered position. There is not
much probability, however, that this tree will live for more than a
few years in this part of the country. The Chinese Hemlock {T. chi-
nensis) was injured by the winter and probably will never be very suc-
cessful here.

Pines. The European and Asiatic" Pinus sylvestris, the so-called
Scotch Pine, the Austrian and other forms of the European Black Pine
(P. nigra), the forms of the European P. montana, and the Swiss and
Siberian forms of the Stone Pine (P. Cembra) have not been injured.
The Japanese White Pine (P. parvijiora), the Japanese Red Pine (P.
densifiora and the Korean form of this tree which the Japanese botan-
ists call Pinas gracilis, seem able to support the New England climate
without injury. The Korean Nut Pine (P. koraiensis) which has produced
seeds in the Arboretum for several years, and the Lacebark Pine of
northern China (P. Bungeana) are uninjured. Of the Pines of western
North America only Pinus monticola, P. ponderosa var. scopulormn,
and P. Jeffreyi grow successfully in the east, and these are uninjured,
as are the eastern American P. pungens and P. virginiana. The
northern Pinus Banksiana, which just reaches northern New England,
with a doubtful station on Nantucket, grows well in the Arboretum
but not as well as it grows much further north. Although killed last
winter in some New England collections, the Japanese Umbrella Pine
was little injured in the Arboretum.

None of the Arbor Vitae in the large collection of these trees here
suffered with the exception of the Chinese Thuya orientalis which is
never a very hardy or satisfactory tree in this part of the country.
It is of particular interest that plants of the we&tern Arbor Vitae, the
so-called Red Cedar of the northwest (7*. plicata), raised here from
seeds gathered in Idaho, have been uninjured, for this is one of the
great conifers of the world. In a sheltered position several plants of
the California Incense Cedar were little injured by the winter. There
has been little injury to the Junipers, and the Larches and the Chinese
Pseudolarix have not suffered.

New Chinese Conifers. It is too soon to say much about the new
conifers introduced by Wilson from northern China. All the forms of
Pinus sinensis are growing well and appear to be hardy. All the
Spruces have also done well with the exception of Picea Sargentiana
which has suffered from cold and will probably not be hardy here.
The Chinese Firs grow less well than the Spruces and only Abies
Delavayi gives much promise of success.

Complimentary

NEW SERIES VOL IV

NO. 18

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF

POPULAR INFORMATION

JAMAICA PLAIN. MASS. NOVEMBER 22. 1918

Dwarf Conifers. Of many of the cone-bearing trees there are ab-
normal dwarf forms, and a few conifers are naturally dwarf shrubs.
The former are of different origin; most of them are seedlings, some
have grown from buds on branches of large trees, and others have
been produced by exposure to excessive cold and high winds, and these
when transferred to more favorable surroundings often lose their dwarf
habit. A good example of a dwarf of the last class is the depauper-
ate Larch which grows at the timber line on Mt. Fugi in Japan.
Seedlings of this little plant raised in the Arboretum twenty-five years
ago are now nearly of the same size as the seedlings of the trees of
the Japanese valleys raised at the same time. In the sandy swamps
of Prince Edward Island Black Spruces not more than two feet high
produce cones and fertile seeds^ and near the timber line of the White
Mountains it is possible to walk on dwarf mats of the Balsam Fir which
lower down on these mountains is a tall tree. Transferred to better
soil where the winter climate is less severe these alpine and boreal
dwarfs would soon assume the tree habit of the species. Dwarfs of
some species, however, which evidently owe their habit to environment,
retain the dwarf habit when transferred to more favorable surroundings.
Such dwarfs are some of the forms of the European Pinus montana from
high altitudes and some dwarf forms of Junipers which reproduce the
dwarf form in their seedlings. Seedling dwarfs have been produced by
many different species, but they are naturally most numerous in species
which have been largely raised in nurseries where seedlings are care-
fully watched and abnormal forms are preserved. It is not surprising
therefore, that trees like the eastern Arbor Vitae and the Norway

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70

Spruce have produced many such forms in nurseries as few other cone-
bearing trees have been so largely raised from seed.

It is only in recent years that dwarf conifers have attracted m.uch
attention, for Loudon in his “Arboretum et Fruticetum Botanicum”
published in 1838 enumerates only ten. These are two dwarf forms of
Pinus montana, two forms of the Norway Spruce, a dwarf Cedar of
Lebanon, a dwarf Red Cedar {Juniperus virginiana), a prostrate form of
Juniperus sabina, and two dwarf forms of Juniperus communis. He
knew no dwarf Arbor Vitae, Chamaecyparis, Hemlock, or dwarf form
of Abies. Beissner in the second edition of his “Handbuch der Nadel-
holzkunde, ” published in 1899, enumerates one hundred and four dwarf
conifers in thirty-one species; of these twenty-five are forms of the
Norway Spruce, eight are forms of Lawson’s Cypress {Chamaecyparis
Lawsoniana), and eight are forms of the Arbor Vitae of the eastern
United States. In addition to the plants enumerated by Beissner there
are a few which originated in this country and which do not appear to
have been known to him.

There is a good but by no means a complete collection of dwarf con-
ifers in the Arboretum, for it is difficult to keep track of the new
forms which appear in the nurseries where large numbers of conifers
are raised from seed and are often given names without descriptions,
and some dwarfs like those of Lawson’s Cypress and the Chinese Ar-
bor Vitae are not hardy here. The Arboretum collection is much vis-
ited, however, by nurserymen for there is now a demand for these
plants, which have their uses in small gardens and are less happily
planted in making low banks of foliage about the base of suburban
cottages.

Perhaps the handsomest of the dwarf conifers in the Arboretum col-
lection is a form of the Japanese Pinus densijiora (var. umbraculifera).
This is a wide, vase-shaped plant which in Japanese gardens is often ten
feet high and broader than high. The leaves are of a bright cheerful
green and comparatively small plants flower and produce minute cones.
Among the fourteen or fifteen dwarf forms of the Norway Spruce
none is handsomer than one of the varieties described by Louden in
1839 (var. Clanbrasiliana). This is a low, very compact, round-topped
bush which rarely grows more than three feet high but spreads to a
diameter much greater than its height. The plant is said to have orig-
inated on the Moira estate near Belfast, Ireland, toward the end of
the eighteenth century and to have been carried to England by Lord
Clanbrasil for whom it was named. Equally good is the variety nana
which has a flatter top and does not grow as tall as the Clanbrasiliana
but spreads into a broad bush. The subglobose var. Gregoriana and
the variety prostrata are interesting plants. Some of the dwarf
Norway Spruces, especially the variety Ellwangeriana, have a ten-
dency at the end of a few years to form a vigorous leading shoot and
eventually to become arborescent.

Two dwarfs originated in the Arboretum in 1874 among seedlings of
Picea pungens, the Colorado Blue Spruce and Abies lasiocarpa. The
original plant of the former is now seven feet high and ten or twelve

71

feet in diameter, and has so far escaped the loss of branches which
disfigures this Spruce after it is thirty years old. Although well worth
the attention of lovers of dwarf conifers, Pinus pungens compacta is
little known beyond the limits of the Arboretum. The seedling of
Abies lasiocarpa retained its dwarf habit for many years but has now
begun to grow more vigorously and to assume the typical habit of the
species. The dwarf of the European Silver Fir {Abies Picea compacta)
behaves here in the same way and after a few years grows out of its
dwarf habit. There is in the collection a small plant of a dwarf of
Abies concolor which is very compact, but it is too soon to speak of
its value. The well known dwarf of the Balsam Fir {Abies balsamea
var. hudsonica) is a real dwarf only a few inches high. A number of
seedling forms of the White Pine {Pinus Strobus) and of the Scotch
Pine {Pinus sylvestris) are in the collection, but the best known and
most generally planted dwarf Pines are the mountain forms of the
European Pinus montaUa which appear in the catalogues of nursery-
men as Pinus pumilio and P. Mughus. There are many forms of this
hardy dwarf; they are broad shrubs with erect or semiprostrate stems
and are rarely more than ten feet high, but often much broader
than tall. Seedlings of these plants show great variation in size and
habit, and new forms are constantly found in nursery seed-beds. The
dwarf form of the Douglas Spruce {Pseudotsuga Douglasii var. globosa)
has proved one of the slowest growing of these plants in the Arbore-
tum collection.

In the common Hemlock of eastern North America the tendency to
variation in seedling plants is unusually strong and dwarfs differing in
size, shape and vigor are often found in the neighborhood of Hemlock
groves. Some of these have been propagated and have received names
but as different names have been used for the same or nearly the same
forms it is not now possible, even if it were desirable, to distinguish
all these dwarf Hemlocks by name.

Among the seedlings of the Arbor Vitae of eastern North America
are found some of the handsomest of the dwarf conifers. There is a
large collection of abnormal forms of this tree in the Arboretum col-
lection and among them none are better than those called “Little
Gem,” compacta and Hoveyi. Seedlings of the Japanese Retinos-
poras {Chamaecyparis obtusa and pisifera) show, too, a great ten-
dency to variation. One of the handsomest of these forms is C. obtusa
nana, a compact, pyramidal, slow-growing plant. The largest speci-
men in the collection is now about eight feet tall. Other forms of
C. obtusa are compact mats which show little indication of growing more
than a few inches high. In the collection there are among others
dwarf forms of C. pisifera^ plants with yellow-tipped branches and
others with yellow and with white leaves and plants of the variety
Jilifera with green and with yellow leaves.

Among the Junipers are found some of the most useful dwarf coni-
fers. Some of these are forms of arborescent species and others
are natural dwarfs which reproduce themselves from seed. Among
the former are three varieties of the so-called Red Cedar of the eastern

72

states {Juniperus virginiana). One of these (var, globosa) is a compact,
round-topped bush taller than broad, and in the Arboretum collection
where it has been growing for fifteen years it is about three feet high.
The history of this plant is not known at the Arboretum. It came here
from Holland and probably originated in a European nursery. The vari-
ety Kosteriana forms a wide open bush with erect and spreading, grace-
fully arching stems from two to three feet tall. This is an unusually
handsome plant which will prove useful for the margins of beds of taller
growing conifers. This variety probably also originated in a European
nursery. More interesting even than these nursery forms of the Red
Cedar is a plant which grows on a few wind-swept cliifs on the coast
of Maine. Plants of this form are not more than eighteen inches high,
with prostrate stems which spread into dense mats sometimes fifteen
feet across. These plants bear fertile seeds, and there are seedlings,
grafted plants and young collected plants growing in the Arboretum,
but it is too soon to judge if they will retain the habit of the wild
plants when planted in less exposed situations. If this form of the
Red Cedar retains its dwarf habit in cultivation it will be one of the
handsomest of the prostrate Junipers. Of Juniperus chinensis there
are a number of interesting shrubs in the Arboretum collection. The
handsomest of these, var. Pfitzeriana, which grows in the form of a
low broad pyramid, is the most satisfactory of all Junipers in this
climate. Fortunately it can now be found in most American nurseries.
There are dwarf round-topped forms of J. chinensis with green and
with yellow leaves which are less than a foot high; and a form of
this Juniper, var. Sargentii, from northern Japan with prostrate stems
makes mats now eight or ten feet across here. This is a form repro-
ducing itself from seed and has proved to be one of the best of the
mat-like Junipers in the collection. With the exception of the dwarf
form of the European J. sabina (var. minor), the lowest Juniper in
the collection is J. horizontalis which has long prostrate stems with
blue-green or in some forms steel blue leaves. This is a North Amer-
ican plant which is widely distributed from the coast of Massachusetts
to British Columbia. There are fine masses of this plant in the collec-
tion. Less well known is J. conferta, another species which covers
with long prostrate stems the sand dunes on the coast of Japan.
Raised first in the Arboretum three years ago from seeds collected by
Wilson in northern Japan there is every reason to believe that this
will prove a useful plant in this country. Another prostrate Japanese
Juniper, J. procumbens, is better known. It is distinguished by its
sharply pointed leaves marked on the upper surface by two white lines.
This Juniper has not produced seeds and is not known except as a cul-
tivated plant; it is planted, however, in nearly every Japanese garden
and has been much planted in California and occasionally in the eastern
states. A dwarf Juniper, J. communis var. depressa, covers thousands
of acres of hillsides in the northeastern states where many forms occur
differing in the height and in the width of the leaves. These are
coarser and less desirable garden plants than J. horizontalis and the
different low-growing varieties of J. chinensis and J. virginiana.

These Bulletins will now be discontinued until next spring.