ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF POPULAR INFORMATION

SERIES 4 VOLUME VII
1 939

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PUBLISHED BY THE

ARNOLD ARBORETUM

JAMAICA PLAIN, MASSACHUSETTS

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ILLUSTRATIONS

A typical rhododendron planting in the Northwest, Plate I, p. 9

Viburnum fragrans, Plate II, p. 15

When the Arboretum was young — 1890, Plate III, 22

Malus ioensis plena (branch) Plate IV, p. 29

Bechtel’s Crab, (Malus ioensis plena) Plate V, p. 27

Index Kewensis in its new Loose Leaf Form at the Arnold Arbore¬
tum, Plate VI, p. 39

Logs awaiting the saw mill in Tom Swamp Pond of the Harvard For¬
est, Petersham, Massachusetts, mute evidence of the terrific de¬
struction caused by the hurricane last fall, Plate VII, P- "13

Eel Pond swamp, Woods Hole, September 29, 1939, Plate VIII, p.
47

Japanese Black Pine (P.thunbergi) was outstanding in its resistance
to salt water, Plate IX, p. 49

Seedling crabapples at the Arnold Arboretum after their first year of
growth, Plate X, p. 66

Granite and shale mountains around the western end of Brintnell
Lake, Plate XI, p. 70-71

[iii]

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF POPULAR INFORMATION

YOf^g;

SOTAN'iCAi.

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Series 4. Vol. VII APRIL 14, 1939 Number l

THE PAST WINTER AT THE ARBORETUM

THE past winter at the Arboretum has been spent chiefly in saw¬
ing wood — literally sawing wood, for with about 1500 trees de¬
stroyed, their removal became a major project. In the Bulletin of
Popular Information of October 7, 1938, a graphic description was
given of the damage done by the hurricane of September 21. Although
a great deal remains to be done, a majority of the fallen trees have
been removed, particularly those adjacent to the roads and walks.
Because an extra force of men has worked full time all winter, the
casual visitor in the Arboretum this spring will see few fallen trees,
but will notice hundreds of stumps here and there in the collections
where trees once stood — grim reminders of the fury of the September
storm.

A great deal of necessary pruning is being done now. It will take
at least three months to complete this pruning program. Trees that
were otherwise uninjured have many broken branches which must be
removed and clean cuts made in order to prevent trouble from irisects
and diseases later on. Everyone in New England is fully aware of the
extreme damage done to trees in the path of the September hurricane.
The Arboretum has done everything within its power to make the
plantings look presentable for the flowering season this spring. Even
with an extra force of men it has been necessary to omit the ordinary
routine tasks normally taken care of in the fall and winter. Although
there is much obvious repair work yet to be done, it is hoped that
spring visitors will appreciate the progress that has been made.

There are at least three areas in the Arboretum so badly damaged
by the hurricane that they will have to be replanted. One of these is
at the rear of the administration building, another at the top of Hem¬
lock Hill and the third, the hill along South Street where so many of
the beautiful torch azaleas were planted by E.H. Wilson about ten

years ago. Evergreens will be used to replant these areas, but they
will not be placed until late August or early September, for that is the
season when such trees are best moved. Since it will be impractical to
water the plants after they are once in place, it is far better to plant
them in the fall, rather than in the spring when they will have to go
through the hot, dry summer months with little attention.

Hemlocks will be used for replanting the top of Hemlock Hill.
Some of the venerable specimens uprooted in the September storm
were growing when George Washington was President, others are
much younger. It will take the better part of a century before the
magnificent grove on Hemlock Hill will again approach its perfection
of September 1938. The soil is extremely shallow, in some places being
only about eighteen inches deep. Because of such poor growing con¬
ditions, it has been thought advisable to replace the large trees with
smaller ones, each young tree with a ball of earth around its roots.
This will enable them to get a quick start. Providing the weather con¬
ditions prove too much for the first planting — several hundred 2—3 foot
plants have been acquired to be cared for in the nursery through two
growing seasons. After this time they will be planted in the more open
places on Hemlock Hill or where some of the other young plants may
have died. It was thought better to replant in stages, rather than to
do the entire task at once and thus take a chance on weather condi¬
tions ; for if one long dry spell occurred after the first planting, many
of the plants might suffer severely or be lost entirely.

The bank at the rear of the administration building was originally
planted with white and red pine. Later, other interesting evergreens
were added. The large grove of white pines was practically eradicated
in the hurricane, and this area will be replanted with small white
pines. Some of the young exotic spruces will be rearranged in the
fall, but to make this planting beautiful once more, it will be neces¬
sary to plant some larger trees. For this purpose, some splendid Caro¬
lina hemlocks approximately fifteen feet tall will be moved from the
Walter Street tract to the hill back of the administration building.
With such good plants, once in place, an interesting evergreen plant¬
ing should be established in a very few years.

Red pines will be replanted on the South Street hill. One of the
last plantings that E.H. Wilson authorized was that of approximately
one thousand torch azaleas on this bank. The bank was well adapted
for such a planting for on it were growing many vigorous red pines
which gave sufficient shade to protect the delicate azalea flowers. When
exposed to the full strength of the sun for any length of time, the
flowers of the torch azalea fade in a very few days, but when given
some shade during the day, they may last for a week or longer. The
hurricane destroyed the majority of red pines on this bank. The thou¬
sand azaleas are still there, mostlv unharmed, but in mid-Mav when

[2]

they will be in bloom, their flowers will be sadly in need of some pro¬
tection from the bright sun. Since the red pine is of very vigorous
growth, it is expected that the three foot plants which will be placed
there this fall will develop rapidly enough to give the needed protec¬
tion within a few years.

A large number of stumps still remain. It is hoped that during the
summer the smaller stumps can be removed. A tractor has been need¬
ed in the Arboretum for a long time and one was acquired this spring
to be used especially for stump removal and to take care of the heavy
work connected with moving the large Carolina hemlocks this fall.
Larger stumps will be cut close to the ground and allowed to rot in
place, as their immediate removal is a very expensive undertaking.
It is a comparatively simple matter with proper equipment to remove
one stump after the other along the highway or street, but when such
stumps are on steep banks and among closely planted trees and
shrubs, it becomes practically impossible to remove them without in¬
jury to adjacent plantings except at very great expense.

Age of Trees Destroyed

Bulletin readers may be interested in the age of some of the trees
destroyed by the hurricane. In the case of those trees about 70 years
of age or older, the figures were obtained by ring counts. For the
younger trees, data were compiled from our planting records, as ac¬
curate data have been maintained appertaining to all trees planted
since 1872.

Age

Canadian Hemlock

157

6 6 6 4

1 54

6 6 6 6

151

6 6 6 6

139

English Elm

133

White Oak

1 15

Sugar Maple

110

Horse Chestnut

98

Tulip Poplar

93

Cucumbertree

69

Red Pine

66

Douglas Fir

65

White Fir

65

White Spruce

65

Blue Spruce

65

Kentucky Coflfeetree

64

Engelmann Spruce

60

Green Ash

59

Pin Oak

56

American Ash

55

Carolina Hemlock

53

Common Pear

50

[3]

European Mountain-ash
Japanese Hemlock

Poplars (practically the entire collection)
London Plane

45

42

40

34

(Note): All these were perfectly healthy trees with solid trunks.
Other trees were blown over, many of them natives but with
rotten trunks. Many of these were very old, possibly older than
any listed above, but it was impossible accurately to estimate
their age because of the decayed interior parts of the trunks.

A fourth area which will be replanted within a year or two is the
slope at the base of Peter’s Hill where the older poplar collection was
located. Since this slope faces the tracks of the New York, New Haven
and Hartford Railroad (Dedham Branch) it affords an excellent am¬
phitheater for a display of flowering trees. It had been decided to
replant this area with a comprehensive collection of the oriental flow¬
ering crabapples. The plants are being grown in the nursery now and
will be ready for transplanting to this bank in a year or two. These
trees are most attractive when in full bloom, and because of their
heavy crops of small colored fruit are again attractive in the fall. In
some species and varieties the fruits remain on the trees well into the
winter.

Individuals familiar with the Arborway may regret to notice the
removal of most of the large willows immediately within the fence.
Because of their age and their brittle nature it was decided in 1937
to remove about one third of them in the winter of 1937-38, which
was accomplished. The plan was to remove another third in the winter
of 1938-39, and the remainder the following winter. Because of the
extreme breakage during the September storm, most of the remaining
trees were removed this past winter, and the few that are left will
be taken out next winter. They are to be replaced by intermixed
plantings of red maple, tupelos and sour woods.

Donald Wyman

(Note): Subscription renewals for 1939 are now due. Those who
have not resubscribed, and who desire to continue to receive the
Bulletin, should remit $1.00 to the Bulletin of Popular Informa¬
tion, Arnold Arboretum, Jamaica Plain, Massachusetts, at an
early date to insure continuity in the receipt of the numbers as
issued.

[4]

ARNOLD ARBORETUM

HARVARD UNIVERSITY

fWUARl
r v,v YORK
TAJSlCAt
(iARUBK.

BULLETIN

OF POPULAR INFORMATION

Series 4. Vol. VII APRIL 28, 1939 Number 2

RHODODENDRONS IN THE PACIFIC NORTHWEST

BY

Herbert Ihrig

Chairman, Rhododendron Committee Arboretum Foundation
Seattle, Washington

THE greatest area in America for growing rhododendrons is the
Pacific Northwest. This territory extends along the coastal region
from British Columbia through Washington, Oregon and northern
California. Owing to the warmth of the Japanese current, climatic
conditions are mild with an absence of extreme heat and cold, but
while the rainfall is generally less than either Boston or New York,
the periods of rain are much longer. This moist weather and a natu¬
rally acid soil seem to meet their requirements to a remarkable degree.
Whether they come from the higher elevations of the Himalayas, the
jagged gorges of Upper Burma or China, or the open moorlands of
Tibet, they readily adjust themselves to our garden and woodland.

These facts have long been known to students of horticulture, but
are not today generally understood in this country. While England
has experimented for more than one hundred years and developed a
literature that reflects a long and continued appreciation of rhododen¬
drons, it is only in recent years that we have made worth while con¬
tribution.

Not only has plant material representing very numerous species
been unavailable, but owing to the embargo that existed tor some
time, we failed to keep pace with the hybrid developments abroad,
especially in England and Holland. Occasionally some individuals
imported seed or a few new hybrids, but little or no record was kept

[5]

of their results, so that interested amateurs like myself were at a loss
as to what to buy or where to buy.

It was for that purely selfish reason that I first began my importa¬
tions. I wished to test some of the better things and to determine
what was hardy in our locality, what really constituted “garden
value,” and what the conditions of soil and growth were.

I started with one great advantage in that most of the English rho¬
dodendron literature is applicable to our climatic conditions, and the
work of the Rhododendron Association in establishing standards was
invaluable as a guide. Its ratings, when criticised as not suitable for
the United States are misunderstood, for obviously those on hardiness
apply only to the British Isles and each rating is so defined. These
ratings give one an established starting point and should be even more
valuable to the eastern experimenter than to one on the Pacific Coast.

Ratings are as follows :

(A) Hardy anywhere in the British Isles and may be planted in
full exposure if desired.

(B) Hardy anywhere in the British Isles, but requires some shade
to obtain the best results.

(C) Hardy along the seaboard and in warm gardens inland.

(D) Hardy in south and west, but requires shelter even in warm
gardens inland.

(E) Requires shelter in most favored gardens.

(F) Usually a greenhouse shrub.

In our Northwest area a plant with an “A,” “B,” or “C” rating
is hardy in most locations. A plant with a “D” rating is generally
hardy, although inclined to be a sparse bloomer except in occasional
years. A plant with an “E” rating can be grown in favorable loca¬
tions, and in my garden R. Barclayi “Helen Fox,” a large, broad-
leaf variety, which is rated “E,” blossoms in early March and has
never missed a year since it reached a blossoming age. I have, also,
grown plants with “F” ratings with light winter protection.

As to “Garden Merit” the English Association’s ratings, like all
such, are subject to change as standards improve and experience var¬
ies, but they can generally be accepted as the best guide available.

On the basis of these ratings, as borne out by local experience, there
are no less than two hundred and sixty seven different species of
garden merit that can be generally grown out of doors in the Pacific
Northwest; nineteen others are suitable for favored locations, and
more than four hundred that are questionable or untried-

[6]

These numbers in themselves give a general idea of the variety of
species, but no figure can impart the beauty and variety of types that
are encompassed, ranging from tiny creepers only a few inches high
to huge trees.

These naturally divide themselves into definite botanical groups,
but for the layman these can be grouped in five general subdivisions:

(1) The broad-leaf varieties

(2) The narrow-leaf varieties

{3) The Alpine or rock garden varieties

(4) The Azalea group

(a) The Hybrids

The Broad-leaf Varieties

In the broad-leaf division lies the parentage of most of our lovely
garden hybrids, and the finest stock comes from India, northern Bur¬
ma, and western China. Representatives of such series as Barbatum,
Fortunei, Irroratum and others do wonderfully well in this area and
embrace many lovely varieties. They range from small shrubs to huge
tree forms, some of which eventually reach the height of forty to sixty
feet ( R.Calophytum 30'— 40'; R. Barbatum 30'-60'). Conditions under
which they grow in their native home, however, vary greatly. Some
come from rain forests ; others high, open woodlands; and the Ameri¬
can grower’s chief task is to find the conditions of soil, exposure, sun,
and shade best suited to their success. While I have grown several
thousand plants of nearly two hundred different species, my experience
is too limited to make any dogmatic statements. Generally I have
found that the larger the leaf the more shade required. Shade, how¬
ever, is a comparative term. It varies in density and moisture content,
two factors of importance and different in various localities. None seem
to do well in “deep shade” or beneath overhanging branches. They
do best with the sky overhead, and their shade intermittently broken
with sunshine such as comes through tall abutting trees.

The Narrow-leaf Varieties

The narrow-leaf group, in which I have included such species as
R. rubiginosum, yunnanense, lutescens, Davidsonianum, heliolepis, and
others, will stand considerable sun and a dryer location.

A number of these have beautiful flowers, but are difficult to place
in a garden as they are sometimes inclined to be unshapely. In an
open, naturalistic planting, however, they are a real joy, and a num¬
ber of R. yunnanense planted with our native Salal ( Gaultheria Shallon )
and Oregon Grape ( Mahonia Aquifolium ) is a sight worthy of a long
pilgrimage.

[7]

The Alpines

When vve consider the alpines and other rock garden varieties even
a general statement is apt to be misleading in that there are many
different ideas as to what constitutes a rock garden type.

Low alpines such as R. myrtilloides, pemakoense , imperator, Calostro-
tum, keleticum, radicans, and similar species have done well in full sun,
but I always try to get their roots well under rocks where they are
protected from direct sun rays and do not dry out.

Almost all of the Lapponicum series which include such varieties
as R.Justigiatum, impeditum, intricatum, russatum, scintillans, etc. do well
in full sun. I grew them in semi-shade for several years and they were
leggy, poorly shaped and sickly, but when moved into full sun sent
out new shoots from the base and main stock so that in two years they
were shapely, healthy, well-grown plants.

R. ciliatum grows to six feet in favorable locations, but when exposed
to full sun breaks out at the base and forms one of the best rock plants
I know. Occasionally a precocious shoot may try to attain height, but
can be easily cut back.

R. glaucum is another that shapes better and remains comparatively
low in the sun. R. moupinense, which I have always protected, as it
blossoms in February, has been moved to full sun and shows material
improvement. R. racemosum does nicely in any location. R.Tephro-
peplum seems to prosper in either sun or shade, but remains lower in
the sun. Then there are some like R. repens that I have been unable
to make happy in any location.

The alpine group is so extensive and varied that it is impossible to
discuss it fully at this time, but it offers perhaps more immediate in¬
terest than any other group because of its beauty, and the demand
for new and interesting rock plants. From it will, no doubt, come
varieties and hybrids that can be generally grown throughout the
United States, and a wealth of beauty awaits the hybridist.

The Azaleas

Experience on the west coast with deciduous azaleas differs little
from that in the east, but in evergreen types we have a great many
new comers such as malvaticum X Kaempferi and Japanese crosses of
eriocarpum,indicum ( macranthum) , scabrum, and others. These undoubt¬
edly have a very definite place in the future. At present these crosses
have become intricate and variations are so slight that the entire group
is sadly in need of standardization.

This will come with time, but meanwhile we will continue to grow
many varieties, all beautiful and interesting, and hope that out of

[8]

PLATE I

A typical rhododendron planting in the Northwest.

them will come more hardy varieties that will be available to a larger
section of the country.

The Hybrids

To the average layman a hybrid is just another Rhododendron, but
it is in reality something quite different. It is the result of a scientific
effort to adjust or improve plants for garden use. It has the heritage
of long years of effort in crossing and recrossing species with species
or with other proven hybrids. These are grown under garden condi¬
tions and take more kindly to garden change. The aims of the hy¬
bridist have been varied. Some have sought to improve hardiness,
some color, form or foliage, and their success has advanced our stand¬
ards to a remarkable degree.

It is true that in “hardiness” this advance has not been all that
could be desired ; for the hybridists have not as yet developed a wide
range of Rhododendrons with color and beauty which are capable of
withstanding the rigors of our northern winters, as has been done for
the more favored climates. But in other ways, such as size and texture
of blossom, clearness and beauty of color, and richness of foliage, their
results are conspicuous.

In the Pacific Northwest area most of these new hybrids are being
grown such as Blue Tit,” “ Betty Wormald,” 4 4 Brittania, ” 44 But¬
terfly, ” “Cornubia,” “Corona,” 4 4 Dr. Stocker, ” 4 ‘ Glory of Little-
worth,” “Goldsworth Yellow,” and many others, but their names
are still strange to most gardeners, and there are many old favorite
stand-bys that have been replaced, not for a whim or a passing fancy,
but because of the inexorable advance of science in a field of beauty.
I do not depreciate the lovely old favorites as there is a beauty of age
in most Rhododendrons for which nothing can be substituted, but I
do urge those who are contemplating new acquisitions to study these
new plants before making their decisions. I am sure that when they
have seen the gorgeousness of a 4 ‘Beauty of Littleworth” or a 4 4 King
George” most other white rhododendrons will pale into insignificance.

This is equally true of the other colors: blush, pink, rose, red,
scarlet, yellow and apricot. Only in the blue and orange ranges does
one feel the need of better colors, and even here “Blue Tit” iimped-
itum X Augustinii ) and the new R. Dichroanthum crosses are doing much
to make up this deficiency.

Those who are familiar only with the American and early English
hybrids have a real treat in store for themselves, for while these ear¬
lier varieties had the advantage of being hardy, they were largely
from North American stock, R. maximum and R. catawbiense, the first

[10]

of which produces small papery flowers, while the Catawbiense crosses
have a tendency to revert to a purple or unpleasant magenta shade.

The newer hybrids made with Asiatic species have acheived not
only size and texture of blossom, but a clearness and depth of color
that must be seen to be fully appreciated. Some even surpass the
catalogue descriptions!

Many British hybridists believe that the use of the hardier Asiatic
rhododendrons, especially those from the higher altitudes, will even¬
tually produce a race of hybrids beautiful in color and size and suit¬
able for general use in our colder sections. Already Mr. C. O. Dexter
of Sandwich, Massachusetts, has done much along this line with For-
tunei hybrids, but there are still many other sturdy varieties unknown
and untried.

Most of these better hybrids, as well as the Asiatic species, are now
in west coast arboreta and private collections and should be available
to the hybridist who wishes to develop a new field of beauty.

Culture

Much has been written about proper soil conditions, but [ have
seen and purchased rhododendrons grown in almost every conceivable
soil from California "gumbo” to loose sand and gravel, so I am led
to believe that other than being on the acid side there are other fac¬
tors that are important. My own experience is that lime in any form
is not only unnecessary, but dangerous. My soil is only slightly acid
and every attempt to treat it with a lime-bearing fertilizer has been
disastrous. I have had splendid success with a soil made up of a mix¬
ture of ^ leaf mold, 4 peat moss, and 4 loose sandy soil. Some var¬
iation of this formula will meet almost any condition, provided the
planting area is well drained.

Rhododendrons need moisture, but at the same time drainage is im¬
portant, for few if any will prosper in wet, soggy ground. In their
natural habitat, most rhododendrons grow in loose, rocky soil with
plenty of moisture around their roots, so that if the soil is loose or
sandy (with excessive drainage) it is well to add leaf mold or peat
moss to aid in retaining the moisture.

The very word pruning is an anathema to rhododendron growers
and properly so when considered in the usual sense of the term. How¬
ever, used judiciously it can do much to improve the plants both in
looks and growth. I began experimenting on our native rhododen¬
drons,/?. macrophyllum (/?. California um), cutting out weak or unsight¬
ly growths. Now I do not hesitate to do this on finer hybrids and

trim them for shape as well. Sometimes this is done for height or
bushiness, sometimes to eliminate crossing branches. Properly done
it will help in the development of good growth, appearance and flower.

There is another form of pruning that will help the shapeliness of
a rhododendron and that is disbudding. This is better than permitting
growth that should later be cut out. Some varieties like 4 4 Earl of
Athlone” tend to crowd their upward growth and both flowers and
foliage are at a disadvantage. By proper disbudding this new growth
can be encouraged to spread out, giving much more room for both
flowers and foliage.

Fertilizers

This is also a controversial subject. Some growers recommend well-
rotted cow manure, others oppose it. Some avoid commercial fertilizers
in any form. I use both with good results. Of course, I do not mean
the promiscuous use of fertilizers, many of which contain ingredients
that are poisonous to rhododendrons, but there are good fertilizers
available, or one can use an accepted formula.

In selecting a fertilizer it is important to select one with an acid
rather than an alkaline reaction, and to get the right proportion of
available food minerals with which to supplement the soil.

What constitutes proper soil balance has not been scientifically de¬
termined, for as previously stated, I have found them doing well in
various soils, but a common factor in all successful formulae that I have
tried seems to be a large potash content. Whether this is due to a soil
deficiency or a special plant requirement, I do not know.

The formula that seems best for Puget Sound requirements accord¬
ing to my own experience is as follows :

10 lbs sulphate of ammonia — Reaction — acid
35 lbs superphosphate 4 4 neutral

20 lbs sulphate of potash

20 lbs cotton seed meal 44 acid

15 lbs aluminum sulphate “ strictly acid

This I apply at the rate of one handfull to a small plant and to

larger ones in proportion. This is simply spread on top of the ground
over the root area and is best done in early spring. Late summer ap¬
plications may start new growth that will not harden sufficiently to
resist the winter cold and consequently be cut by frosts. Woodland
plantings require less treatment, and the usual mulch of leaves and
pine needles will generally suffice.

[12]

i.in

ARNOLD ARBORETUM

HARVARD UNIVERSITY

I IhK A fctJf

BOTANICAL

oakpk®-

BULLETIN

OF POPULAR INFORMATION

Series 4. Vol. VII APRIL 29, 1939 Number 3

THIS HESITANT SPRING

UDS are swelling at the Arboretum, but their opening is far be¬
hind schedule. The continued cold, cloudy spell will be respon¬
sible for many peculiarities in blooming dates this year. Some plants
are as much as three weeks late in flowering. Viburnum fragrans, for
example, is just now starting to flower. Only half of the flowers of
Magnolia stellata are open at the time this is being written. About half
of the buds near the top of the trees came into bloom last week, but
the rest have remained tightly closed, awaiting warmer weather.

Forsythias should be in bloom now. There are many bushes at their
height of color in warm, protected places in the city, but at the Ar¬
boretum, forsythias are just beginning to show patches of yellow here
and there. Forsythia ovata — normally opening a week before the rest —
came into flower only a few days ago. The spice bush is not yet in
full bloom, but various species of Corylopsis have been in flower for
about a week. Rhododendron mucronulatum is not a mass of colorful flow¬
ers — yet. Many of the flowers opened on a warm day last week, but
the weather has been so cold since that the majority of flower buds
are still closed. When these buds do open the flowers which have been
out for some time will undoubtedly begin to fade, so that the display
of color made by these plants this year will be mediocre. The same
is true of Magnolia stellata, plants gowing in front of the Administration
Building. Fortunately the plants of M. stellata rosea in the lawn in
front of the building are still in tight bud; and if we have a warm
spell of several days’ duration, these plants should make a splendid
display.

The winter has been a very mild one, at least as far as the woody
plants at the Arboretum are concerned. It is true that some of the

[ 13

evergreens have been slightly burned, but this was done by the hur¬
ricane of last September and not by the winter. Apparently, there
has been no serious winter injury to flower buds. One of the ^indi¬
cator” plants in this respect is Viburnum fra grans, which is injured
so frequently by cold in the winter. This spring all the flower buds
are in excellent condition, and now they are gradually opening. This
is a fine plant for early spring flowers, but is best used south of New
England where it is reliably hardy. The late season is well illustrated
by a list of blooming dates kept by Mr.W.H.Judd, of the Arboretum
staff, and reproduced in part on page 16.

Notes

Dr. E. D. Merrill, Administrator of Botanical Collections, Harvard
University, and Director of the Arnold Arboretum, has just received
through the State Department, the gold medal of the Ministere de
1’ Agriculture of the French Republic and the corresponding diploma
of the Societe Nationale d’ Acclimation de France. These were con¬
ferred on Dr. Merrill at a session of the Societe d’ Acclimation in Paris
on February 12, 1939, in appreciation of his services to French horti¬
culture.

Estimated Blooming Dates for the Arnold Arboretum, 1939

Magnolias

Single-flowered Japanese cherries, shadbushes
Crabapples, double-flowered Japanese cherries
Torch azaleas

Lilacs, wisterias, deutzias. hawthorns
Rhododendrons

May 3-7
May 3-7
May 15-20
May 18-24
May 20-24
June 1 0- 1 5

It is extremely difficult to predict reasonably accurate blooming
dates in advance this year. Those given above should be considered
only as approximations. A very warm spell in early May will change
them all.

Donald Wyman

PLATE II

Vi burn u m fragrans

Photographed in the Arnold Arboretum, April 15, 1931,
by Professor Oakes Aines

Blooming Dates of Individual Plants in the Arnold Arboretum*

Year

’31

’32

’33

’34

’35

’36

’37

’38

’39

Abeliophyllum distichum

— -

—

—

21

17

1

—

1

24

Acer rubrum

10

—

1

9

18

M3Q

1 1

M23

20

Acer saccharinum

Ml

Jl5

J24

Ml7

Mil

M 1 7

J 1 4

M23

M5

Benzoin aestivale

—

21

29

19

—

19

19

15

28

Cercidiphyllum japonicum

12

20

21

18

20

12

17

14

28

Corn us mas

7

3

1

13

17

16

10

1

. 20

Corylopsis pauciflora

25

23

29

22

19

3

- —

15

25

Daphne mezereum

5

- — ■

9

1

M25

—

8

M25

20

Dirca palustris

3

10

9

7

21

M30

14

14

20

Forsythia ovata

10

17

—

18

19

1

4

1

20

Hamamelis mollis

F25

Jl 5

J25

- —

M7

M20

Jll

— -

—

Hamamelis vernalis

N29

D3

N28

N21

D12

Dl3

D 1 9

N21

—

Lonicera praeflorens

2

2

M30

7

10

M27

9

1

13

Lonicera standishi

12

J2 1

19

18

18

—

—

1

22

Magnolia denudata

17

21

—

19

20

22

20

15

29

Magnolia kobus borealis

17

20

29

19

—

19

19

15

m?

Magnolia soulangeana speciosa 18

24

■ —

21

25

23

23

m 1

m?

Magnolia stellata

10

17

19

15

19

M31

12

14

29

Prunus armeniaca Mikado”

20

21

- — •

—

—

22

25

16

m?

Prunus concinna

22

29

29

—

- —

23

ml

19

m?

Prunus davidiana

10

6

9

—

—

M30

9

1

22

Prunus incisa

22

28

ml

26

27

24

ml

20

m?

Prunus mandshurica

17

20

—

20

—

14

17

13

m?

Prunus nigra

30

ml

- —

m 1

ml

—

m7

20

m?

Prunus sargenti

20

29

m 1

22

26

22

m 1

20

m?

Prunus subhirtella

22

29

21

—

27

25

m 1

20

m?

Prunus subhirtella pendula

22

29

29

—

27

—

ml

20

m?

Prunus tomentosa

20

21

- —

25

27

23

25

16

m?

Prunus triloba multiplex

22

ml

—

—

28

ml

ml

20

m ?

Rhododendron dauricum

—

J 1 3

—

—

—

—

10

M27

20

Rhododendron schlippenbachi

m3

—

—

—

ml

—

m5

28

m?

Rhododendron vaseyi

m 9

—

— -

m6

—

m 8

ml 3

m 1

m?

Ulmus americana

3

3

—

3

1

M29

M 13

M23

M20

Viburnum fragrans

5

J 1 4

8

15

19

M30

J 1 5

10

20

*These figures have been supplied by Mr. W. H. Judd, Propagator at the
Arnold Arboretum. The dates represent the first day each plant could be con¬
sidered to be in full bloom. The same plant has been inspected each year for
this information.

Note: All dates given are for April unless otherwise noted.

N = November
D = December
J = January
F = February
M = March
m = May

[16]

o

ARNOLD ARBORETUM

HARVARD UNIVERSITY

«- ^ li

BULLETIN

OF POPULAR INFORMATION

Series 4. Vol. VII

MAY 5, 1939

Number 4

NEW ENGLAND MUST PLANT TREES THIS SPRING!

THERE is ample opportunity for every town in New England to
initiate a carefully planned tree planting program this spring, and
the need for this is very great. After the devastating hurricane of last
September, the streets of many towns have been frightfully marred by
the loss of valuable trees, and civic organizations everywhere in New
England are uniting in planning intelligent tree planting programs for
the streets and highways as well as on private property.

There are a few important points to be kept in mind when planting
trees anywhere ; some are common knowledge, but others may be un¬
known to the individual who has had little or no previous experience
in this field. Briefly, these points are as follows:

Transplanting in the spring should only be done when the soil is
well dried and in workable condition. When soil is wet or muddy, any
handling or working will Spuddle” it; that is, the air spaces will be
closed up when worked, and the soil may dry out in almost brick-like
consistency. In such soil it is almost impossible for plant roots to grow.
Consequently, the time of actually planting trees will vary consider¬
ably over the New England area. As soon as the soil is in good condi¬
tion plant immediately, for the longer the period in which the tree
has to grow, the better off it will be.

The hole dug for the tree should be deep and ample. The tree itself
should be set not more than two inches deeper than it was formerly.
Remember that it is always better to plant a fifty-cent tree in a three-
dollar hole than a three-dollar tree in a fifty-cent hole.

If drainage is poor, a drain should be put in the bottom of the hole.
If there is a hard clay bottom, it should be broken up with a pick axe.
If the soil is very poor, it might well be removed entirely, a good layer
of well-rotted manure (never use fresh manure) placed on the bottom
of the hole, and good top soil filled in firmly underneath and on top

[IT]

LlttRAKT
rtf: W YCtRK
BOTANICAL

of the roots. Sometimes a tamping stick is used for this, since it is im¬
perative to get plenty of soil well-firmed under the roots as well as on
top of them. Some tender barked trees, such as birch and beech may
do better if their trunks are wrapped in burlap for several months
after transplanting.

It may be advantageous to leave a slight depression around the tree
in order to catch water, for the newly transplanted tree needs much
water, and it should be carefully and conscientiously watered during
the dry periods the first year. At the time of transplanting, the tree
should be either staked or guyed with wires which are run through a
rubber hose around one side of the tree only, so that it will become
established in the correct upright position. The wires should be left
on for the first year or two.

A word of caution is needed for the person who wants to dig and
transplant trees from the woods. Sometimes this proves successful, but
more often it results in failure because the roots have never been
pruned. Such trees are very difficult to transplant unless every root
is carefully dug and protected against drying out during the trans¬
planting process, and the roots are apt to be greatly elongated. It is
usually better to buy trees from nurseries, for such trees have been
periodically root pruned, thus rendering it easier and safer to trans¬
plant them.

Pruning and Later Care

It is a comparatively simple matter to plant a tree. Anyone can do
it. If reasonable care be taken in the transplanting operation, the tree
will live. However, no planting program is complete without a word
of caution concerning the later care of the tree. It must be pruned
somewhat as soon as it is in its new situation. The pruning of branches
is necessary to compensate for the loss of roots cut off in the trans¬
planting operation. Trees which were severely wrenched or tilted by
the hurricane might also have some branches removed. This is fre¬
quently hard to do, but results in much better growth. The tree must
be carefully watered ; evergreens must have their tops sprayed in the
evenings of particularly hot summer days; bad crotches among the
branches must be located and eliminated; disease and insect troubles
must be cared for as they appear, and often it is wise to take prevent¬
ative measures before they appear. The experienced gardener knows
these things and is always prepared to act when such difficulties arise.

What Trees to Plant

Contrary to popular belief, there is a wide variety of trees which
can be planted along the streets of New England towns. There is noth¬
ing quite like the American elm and the sugar maple, both of which
are native here. Yet, since the time our forefathers planted the streets
so marred by the hurricane, a surprisingly large number of hardy exotic

[18]

trees have been introduced and tested, and these offer splendid oppor¬
tunities for interesting planting. Then, too, there are many trees na¬
tive to this country which might very well be included in any tree
planting program. All the streets of a town do not have to be planted
with the American elm or sugar maple. If the property owners on a
certain street unite in the desire 4 4 to plant something different,” let
them, by all means ! They might try the beautiful flowering Sargent
cherry, the mountain silverbell, or even the flowering dogwood ! If
they want brilliant autumn color combined with splendid summer foli¬
age and flower, they might use the southern sourwood. The sweetgum
is also a possibility. If the street is very narrow, there are other plants
besides the Lombardy poplar. The upright growing variety of the
English beech, ginkgo or hornbeam are all possibilities.

New England towns now have a splendid opportunity for making
their streets interesting to a public which is becoming increasingly
plant conscious. The following suggestions are given to indicate some
of the trees that might be used. All are available from nurseries, and
if they cannot be located in local nurseries, the Arnold Arboretum
will be glad to indicate where they may be obtained.

Suggested List of Trees for Planting in New England

(Those marked with an asterisk are not hardy in the northern
parts of Maine, New Hampshire and Vermont.)

Trees for Wide Streets

Acer saccharum
Celtis occidentalis
Sophora japonica
Fraxinus americana
Fraxinus lanceolata
Gleditsia triacanthos inermis
Liriodendron tulipifera
Phellodendron amurense
Platanus acerifolia
Populus alba
Prunus sargenti
Quercus palustris
Quercus rubra
Ulmus americana
Ulmus campestris

Sugar Maple
Hack berry
Katsura-tree
White Ash
Green Ash

Thornless Honeylocust
*Tuliptree
Amur Corktree
*London Planetree
White Poplar
*Sargent Cherry
*Pin Oak
Red Oak
American Elm
^English Elm
Width Streets

Trees for Medium

Acer platanoides
Acer platanoides schwedleri
Crataegus crusgalli
Halesia monticola
Liquidamber styraciflua
Magnolia acuminata

Norway Maple
Schwedler Maple
Cockspur Thorn
*Mountain Silverbell
*Sweetgum
*Cucumbertree

[ 19]

Oxydendrum arboreum
Quercus coccinea
Quercus phellos
Quercus imbricaria
Nyssa sylvatica

Sassafras albidum (S. officinale)
Tilia cordata
Tilia vulgaris
Tilia tomentosa

^'Sourwood
'^Scarlet Oak
* Willow Oak
Shingle Oak
^Tupelo
^Sassafras

^'Littleleaf European Linden
^Common European Linden
^'Silver Linden

Trees for Narrow Streets

Carpinus betulus fastigiata
Carya glabra
Cercis canadensis
Cornus florida
Crataegus phaenopyrum
Crataegus phaenopyrum fastigiata
Fagus sylvatica fastigiata
Ginkgo biloba fastigiata
Populus alba pyramidalis
Quercus robur fastigiata
Tilia platypbyllos fastigiata
Ulmus americana Moline Elm”

^Pyramidal Hornbeam
Pignut Hickory
* American Redbud
^Flowering Dogwood
Washington Hawthorn
Pyramidal Hawthorn
^'Dawyck Beech
Columnar Ginkgo
Bolleana Poplar
^Pyramidal English Oak
*Pyramidal European Linden
Moline Elm

Other Trees and Tall Shrubs for Ornamental Planting
on the Home Grounds

Fagus sylvatica

Ilex opaca
Cladrastis lutea
Syringa japonica
Caragana arborescens
Viburnum lentago
Viburnum prunifolium
Elaeagnus angustifolia
Amelanchier laevis
Pseudotsuga taxifolia
Pinus resinosa
Pinus strobus
Tsuga canadensis
Tsuga caroliniana
Picea omorika

Oriental Crabapples (many types valuable for
flowers and fruits)

^Magnolias (for flowers)

^Japanese Cherries (for flowers)

*European Beech (several varieties for interest¬
ing form and color)

^American Holly (for fruits)

*Yellowwood (for white flowers)

*Japanese Tree Lilac (for flowers)

Siberian Pea-tree (for yellow flowers)
*Nannyberry (for flower and fruit)

Blackhaw (for flower and fruit)

Russian-olive (for gray foliage)

Allegheny Shadblow (for flowers)

Douglas Fir (evergreen)

Red Pine (evergreen)

White Pine (evergreen)

Canada Hemlock (evergreen)

Carolina Hemlock (evergreen)

^'Serbian Spruce (evergreen)

Donald Wyman

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF POPULAR INFORMATION

Series 4. Vol. VII

MAY 12, 1939

Number 5

t °

THE NORTH MEADOW

HE Jamaica Plain Gate is one of the most attractive approaches

A to the Arnold Arboretum in the first warm days of spring. The
magnolias planted about the Administration Building, which stands
just inside the gate, are among the earliest flowering shrubs to open
their buds. They enjoy particularly good conditions here because,
being mainly on the south side of the building, they are exposed di¬
rectly to the warm sun; also they are protected from cold winds by
the building and the hill behind it. About the same time the red ma¬
ples on the opposite side of the road are opening their scarlet flowers,
and the willows nearby are producing catkins.

It was decreed in the original plan of the Arboretum that the trees
and shrubs should be arranged in a sequence which would conform
to a commonly accepted view of their relationship. The scheme chosen
was that of the great British botanists of the last century, Bentham
and Hooker. Consequently, as one goes along the Meadow Road past
the magnolias, he first finishes the Magnolia Family by passing their
relatives, the tulip-trees, which grow on the hillside near the place
where the bridle-path turns off. These trees do not flower until late
May. Just to the south of the road and partly hidden by tall shrub¬
bery is a grass path along which is a large planting of gooseberries
and currants which flower attractively in May. The old-fashioned
golden currant, Ribes odoratum is one of the most fragrant and most
popular in this group.

Proceeding along the road one notes that it is on a low embank¬
ment, with wet meadow on the left and park-like expanse on the right.
The embankment itself had been planted with Cercidiphyllum, Phello-
dendron, and Evonymus on the right, and with Cercidiphyllum, shad-

bushes, maples, buckthorns, and sumacs on the left. The Cercidiphyl-
lums put forth their bluish-green leaves early, but these are preceded
by a wealth of small flowers that have bright red stamens. Although
of an unfamiliar sort, the Cercidiphyllums have a form more or less
characteristic of our native deciduous trees. The Phellodendrons, on
the other hand, possess an “awkward,” unsupported branching form
that is foreign to our usual eastern American concept of what a de¬
ciduous tree should look like.

The linden and horseehestnut collections are among the finest of
their kind in America. They appear to be thriving in the low but
fairly well-drained field which extends from the road westward to the
wooded gravelly knolls nearby. In late May the horsechestnuts and
buckeyes are covered with their upright, conical inflorescences, rang¬
ing from white or cream-color to deep pink and red.

Between the Meadow Road and the Arborway is a low swampy area
which remains wet during a large part of the year. At its lower end,
just across from the Administration Building, are the remnants of a
once-large willow collection. Strangely enough many species have
failed to do well here, chiefly because the water table has been at
such a high level that even willows cannot survive ! A row of tall wil¬
lows along the Arborway fence had grown so large that its overhanging
branches threatened traffic on the street. A part of these were removed
in the winter of 1937-38, and the remainder were so severely damaged
in the hurricane of September, 1938, that most of them were taken
out last winter, leaving a few surviving veterans to be disposed of
later. It is being replaced with a planting of red maples and tupelos
whose brilliant red autumn color will eventually become one of the
Arboretum’s outstanding autumnal displays. On the opposite side of
the low ground, northwest of the lindens and Cercidiphyllums is a
curving grass path lined with honeysuckles and viburnums. Back of
this is the bridle path, recently improved by the city from a mudhole
to a well-drained roadway.

As in most of the Arboretum, the evidences of earlier history are
here nearly all erased. Along the bridle path, and roughly bordering
the property of the Adams Nervine hospital, is a row of tall ash trees
(now badly damaged by the hurricane) which appear to have marked
an old boundry of the low meadow. Although it is not now visible,
one of the oldest surveyed lines in the town of Roxbury passes through
this tract. When the original settlers in the town divided among
themselves the lands in the outlying districts, they laid down a line,
trending roughly northwest and southeast, as a base from which to

[22]

PLATE III

When the Arboretum was young. Picture taken at Jamaica Plain gate, 1890.

■

:

-

measure. This was known as the “headline of the first division,” and
in our area extended from a point among the shadbushes and Cercidi-
phyllums across the wet meadow and the Arborway so as to margin
the westerly curb of Park Road. Farther over the hill the line marks
the end boundary of the Bussey Institution grounds. This line was
the northeast boundary of the original Arboretum. Later the present
extensions of the tract to the Jamaica Plain Gate and to Centre Street
were added by the city or by the University.

Most of the low ground, notably that west of the Meadow Road
and the southerly half of the remainder, is mentioned in the oldest
land records in Roxbury as “Gore’s Meadow.” It remained a meadow
throughout its history to the time of the Arboretum plantations. As
such it was in demand among the early settlers who had to have nat¬
ural feed for their stock. Most of the countryside was originally wood¬
ed except, perhaps, for the low stream margins and swampy areas;
and even when cleared, the production of forage in the dry hillside
pastures was meager. Consequently the farmers used the coarse grasses
and sedges of the natural meadows to good advantage, and utilized
every means at their command to drain the wetter parts so that they
could be used. The old maps of our wet meadow show the arrangement
of these early drainage ditches, which were also the dividing lines
between small parcels of land which were bought and sold separately.
The part west of the road was evidently most in demand because it
was higher and needed less artificial drainage. Parts of it changed
hands twenty or more times during the first 200 years after the lands
were granted.

The original vegetation can only be suggested. It was probably a
grassy or sedgy meadow, for this term was used for it in the earliest
land records. Nevertheless, at some early date it must have had a
swampy forest, for cedar logs have been taken from excavations in the
underlying peat. The only record we have that the peat was ever used
for fuel is in a deed given by Eleazer Weld to one Daniel McCarthy
in 1784, giving the latter the right “to cut Sufficient TurflT for fuel
for the Necessary Support of Two Families ... so long as Turff can
be cut on said . . . meadow land.”

The Meadow Road was built by 1890, making possible the planta¬
tions on its borders soon after. The Arborway was completed in 1895,
and its border plantation of willows was put in about that time. A
small stream known as Goldsmith Brook, which rises in the hills west
of Centre Street, formerly had a channel through the meadow. It was
brought under partial control in 1892; and the lindens, horsechest-

[23]

nuts, and neighboring groups were planted in 1894. The arrangement
did not prove satisfactory, however, and the brook was finally confined
to an underground conduit in 1905. Drainage from the lower part of
the meadow was somewhat improved in 1900 when the eastern sewer
level was lowered between the Arborway and Stony Brook. It is still
unsatisfactory, however, for the meadow is flooded at least once a
year, often nearly to the level of the Meadow Road. Since nothing
can be planted there, the weeds are allowed to grow rankly through¬
out the summer. Fortunately they are composed largely of wild as¬
ters, mints and goldenrods, which make a blaze of color in late summer
and early autumn when the Arboretum is otherwise reduced to browns
and dull greens.

These low grounds at the northeasterly end of the Arboretum have
been difficult to make attractive. Nothing could be done at all until
the water level was lowered by local ditching or by lowering the sewer
barriers. The Meadow Road gave a mass of stable and well-drained
soil which could be used for suitable border plantings. We owe a trib¬
ute to the foresight and sense of proportion which were shown by the
founders of the Arboretum in laying out the plantings. They had to
visualize as best they could the mass effects of trees and shrubs as they
would appear 50 to 75 years after they were planted. That they ac¬
complished an admirable task is evident on every hand in the Arbo¬
retum, and no more so anywhere than in the north meadow. But much
remains to be desired in the low swamp across from the Administra¬
tion Building. The variety of possible plantations will always be limited
by the excessive peaty substratum. If the whole were to be filled up
it would be necessary to open it as an unsightly dumping ground for
a considerable period of years.

It has been suggested that a permanent pond for hardy water lilies
might be established by excavating a portion of the peat bog and uti¬
lizing the excavated material for filling other parts of this area. This
would add a very attractive feature to the meadow and should at the
same time increase the area of higher land which might be used for
permanent plantings.

This might be a feasible solution^ for there is an abundance of water
both from the brook which enters the lowland from a culvert just east
of the building and from the old Goldsmith Brook. Both of these flow
throughout the summer.

Hugh Raup

[24]

6£fii q

ARNOLD ARBORETUM

HARVARD UNIVERSITY

v***.

-p /U

‘**s

BULLETIN

OF POPULAR INFORMATION

Series 4. Vol. VII

MAY 19, 19S9

Number 6

FLOWERING CRABAPPLES FOR SPRING AND FALL
T THIS TIME of year in New England and New York, the

El flowering crabapples are in full bloom. Collected from widely
segregated places in the northern hemisphere, nurserymen in this
country are able to offer over fifty of them to the public. Generally,
they can be grown wherever the common apple does well, and, though
subject to similar apple troubles such as borer and scale, they are an
asset to any garden. The sizes and shapes of the twenty-five different
crabapples listed in this bulletin differ greatly.

Mains baccata mandshurica is not only the first to bloom, starting
this year while the Japanese cherries were still in flower, but is also
the tallest, growing fifty feet high or more. On the other hand, Mains
sargenti is the smallest, often growing twice as broad as it does high
and seldom becoming over 8 feet tall. This might be the best crab-
apple for the small home garden where space is the limiting factor.
Unfortunately, nurserymen often grow it from seed which has not
been collected from pure stands, resulting in trees that do not have
the typical low-growing habit but are much more upright. Since there
are few, if any, pure stands in this country, grafting might better be
resorted to in order to insure the typical form. The rest of the flow¬
ering crabapples range in height from 15 to 30 feet, the majority of
them being 15 to 25 feet tall. Some, like M.haUiana parkmani, rarely
exceed 15 feet, while others like M. ioensis plena and M.Jloribnnda
may attain 30 feet. Some of the varieties, like M.prunfolia rinki, are
upright and spreading in habit of growth ; others, like M.Jloribnnda
and M. arnoldiana, are generally mound-like in appearance.

The most picturesque in habit is the tea crab, now called M.hupehen-
sis, but listed in nursery catalogues as M.theifera. The main branches,

[25]

originating from the trunk, are long with few side branches, appear¬
ing from a distance somewhat like a huge fan. It is always outstanding,
particularly when planted in front of grouped pines or hemlocks.

Like the common apples, the flowering crab has a strong tendency
to be alternate bearing, that is, fruit production is poor one year but
good the next. Though this may not be particularly noticeable in the
flowering, it is very noticeable and often disappointing in the fruiting
habits. For instance, the best fruiting tree in the group at the Arbo¬
retum ( M.toringoides ) was marvelous in fruit during the fall of 1936,
but in 1937, even the largest plant was uninteresting because of few
fruits.

The Oriental crabapples (see table) are the first to bloom, followed
shortly afterwards by the native species. The flower display lasts about
a week, but, of course, depends entirely upon the weather, and this
year is considerably retarded because of the unseasonable cold weather.
When this issue of the Bulletin reaches its readers the crabapples will
be in full bloom at the Arboretum. Some years when the weather is
particularly cool the beauty of these plants is prolonged.

For instance, the Tea Crab is charming with its long slender branch¬
es clothed with delicately-colored flower buds. It is almost the ideal
among crabapples, since the deep pink of the buds, touched here and
there with a tinge of white, blends beautifully with the bright green
of the unfurling leaves. When these buds begin to open, it is noticed
that the petals are white inside and this color becomes predominant,
the pink on the under-side slightly fading to white, so that instead
of having a pink-flowered crabapple as might be reasonably supposed
from a view of the pink buds, actually the flowers are white in color.
Although most of the crabapples are either red to pink or white in
flower, the Purple Flowered Crab ( M. purpurea ) is unusual with its
striking reddish-purple flowers that are particularly conspicuous. The
fruits, veins of the leaves and even the wood of the twigs of this pe¬
culiar plant are all a slightly reddish-purple shade.

One of the best of color combinations can be obtained by planting
a single Carmine Crab, ( M.atrosan guinea ) the flowers of which are a
very beautiful deep carmine, in front of two Japanese Flowering Crabs
( M.floribunda). These latter are light pink as the flowers open but
fade to white almost immediately. Since the Carmine Crab and the
Japanese Flowering Crab are about the same height, seldom over
twenty-five feet tall, dense, bushy and mound-like in habit of growth,
and bloom at the same time, such a combination is never forgotten,

PLATE V

Bechtel's Crab, Malus ioensis plena

particularly when planted so that they are viewed with an evergreen
background of pine or hemlock foliage.

In the late summertime, the crabapple fruits begin to color, natural¬
ly becoming conspicuous against the green background of leaves. The
fruits of a few species are an inconspicuous green, the fruits of the
Purple Crab, purple. Many fruits are red like those of the Zumi Crab,
some are bright yellow, but the ones we value the most are red and
yellow, red on the side towards the sun, and yellow on the side away
from the sun. Such is the fruit of the Cherry Crab, and the Cutleaf
Crab, M.loriitgoide. ?, the best of all the crabapples for ornamental fruit.
It was introduced into this country for the first time in 1904 and since
that time has proved itself the best in fruit of the hundred different
kinds growing at the Arnold Arboretum in Boston. The individual
fruits are almost half an inch long, slightly pear-shaped, and colored
a glorious mixture of red and yellow, red on the side turned towards
the sun and yellow on the side shaded from the sun. For a good
yellow-fruited form, the Arnold Crab, originating in the Arnold Ar¬
boretum before 1883 as a chance hybrid, is probably the best since
its fruits are a brilliant golden yellow. It is difficult to say what va¬
rieties are most enticing to birds, for in years when birds are numerous
almost all of the varieties prove attractive, although there is a tree
here and there which for some reason may be left untouched.

In New England and parts of New York, past winters have demon¬
strated that the double-flowered Japanese cherries are not dependably
hardy. Gardeners in general should realize that the crabapples are
considerably hardier and that there are also double-flowered forms
(see table) . Though these may not be considered as worthy substitutes
for cherries, they can at least be depended upon for bloom. The least
hardy of all the crabapples is the Parkman Crab, M. halliana parkmani,
which was injured considerably during the winter of 1933-1934, both
in New York and at the Arboretum.

The method of propagating these plants varies considerably. Many
of the species can be easily grown from seeds, but in botanic garden
collections, where a number of species are in close proximity, there
is ample opportunity for cross polliniation ; and it has been definitely
proved that M.sargenti when grown from seed thus collected does not
give plants with the desired low-growing habit but rather plants with
a more upright form. It is much safer to bud or graft all forms, ob¬
taining buds or scions from stock plants with known characteristics.
There is a confusion in the nomenclature of the crabapples in many

[as]

Mains ioensis plena

Photographed in the Arnold Arboretum, May, c2(i, 1931,
by Professor Oakes Ames.

PLATE IV

nurseries today, simply because large scale production from seed has
resulted in many variations from true types.

Asexual reproduction naturally brings up the problem of under¬
stocks, which is by no means definitely settled. The American species
are best grafted on seedlings of M.ioensis or M.coronario. Both French
crab seedlings and those of the various Asiatic species have proved suc¬
cessful for the Asiatic forms, especially M. robusta.

Crabapples are hosts of Juniper rusts, and the Arnold Arboretum
has found the Asiatic species to be the least susceptible. There are
places around Boston where Bechtel’s crab becomes so disfigured with
this disease that it is not grown. Bordeaux has been used in efforts
at control but with little success. After several years of careful inves¬
tigation, the Arnold Arboretum recommends the following for the
control of this troublesome disease on ornamental flowering crab-
apples: Use 5 to 6 pounds of “Linco,” a colloidal sulphur spray
produced by Linder & Co. Inc., 296 North Beacon St., Boston, Mass.,
with 100 gallons of water with 3 pounds of “ S. S. S.”, a commercial
4 ‘ spreader” available at any store selling spray materials. Spray at
first when the young leaves become visible and follow with four or
five sprays at six to ten day intervals. Spraying just before a rain
gives optimum results. To control chewing insects, add 4 pounds of
lead arsenate to one of the later applications.

It should be mentioned that crabapples must be sprayed for scale.
At the Arboretum Sunoco Oil is applied as a dormant spray, one part
of oil and 15 parts of water, the application being made sometime
between the middle of February and the first of April.

During the next few years the Arboretum will replant the slope at
the base of Peter’s Hill where the poplar collection was located before
the hurricane. This has already been mentioned in a previous issue
of the Bulletin (Vol. VII, No. 1 ; April 14, 1939). Over a thousand
seedlings are now being planted in our nurseries and will be ready to
plant in the permanent collections within a few years. This is the
result of a definite plant breeding program and it is hoped that at
least a few new and interesting varieties will be found in this large
number of seedlings.

Crabapples are easily grown in a large number of soils and situa¬
tions. They are of ornamental interest several seasons of the year and
are excellent for attracting birds. We should recognize these sterling
qualities and plant more of them !

[30]

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“Species native to the United States.

00 “Oriental Flowering Crabapples’’ native to China and Japan.
SD = semi double

Notes

At the time of writing the weather is still unusually cold. There
have been frosts for the past three nights with strong indications of
another tonight. At the present time the Magnolia soulangeana va¬
rieties are still at their height of bloom. Amelanchiers have been at
their best for the past few days but will soon drop their petals rapidly.
Forsythias are still gorgeous, but they too, will lose their brilliance
as soon as one or two warm days force the vegetative shoots into
growth. The single flowering cherries are past but the double flower¬
ing cherries will soon be at their height of bloom.

This week end will find the Japanese quinces in full bloom; the
crabapples approaching their peak and some of the early flowering
azaleas like the royal azalea and the pink-shell azalea will be particu¬
larly conspicuous.

Lilacs should be in full bloom during the week end of May 27,
with May 28 being Lilac Sunday. At this same time the thousands
of torch azaleas planted on the hills in the Arboretum should be at
their best.

Donald Wyman

A last minute inspection of the lilacs discloses the fact that they
show more flower buds than they have for many previous years.

Consequently the lilac display this coming week will certainly be
worth a trip to the Arboretum.

[32]

If

K

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF POPULAR INFORMATION

library
new yorm

UOTANiCAb

Series 4. Vol. VII JUNE 23, 1939 Number 7

SOME TWINING VINES

ASK any gardener how many species of hardy ligneous twining
vines there are, and the answer may be from six to twelve ; yet,
the Arnold Arboretum has approximately 65 species and varieties of
hardy twining vines growing within its boundaries. Truly a surprising
number ! And this is not all, for if the other climbing vines are added
to this list, the total number of woody vines actually growing in the
Arboretum today is well over 150. All of these are not good landscape
plants, but there are some which might well bear further investiga¬
tion by the interested gardener.

Old-fashioned vines like Actinidia arguta, Aristolochia durior , and
Celastrus scandens are all grown here, of course. So are the Chinese
and Japanese wisterias ( Wisteria sinensis and W. fioribunda) . However
there are 34 other wisteria species and varieties being grown also,
many of which have been added to the collections during the last
three years. It is doubtful if all the varieties in this genus now being
offered by American nurseries are distinct and worthy of individual
varietal names; nevertheless, all are now being grown on a long arbor
recently erected near the old Bussey Institution Building, and after
they become well established and produce Bowers, it will doubtless
be most interesting to study their differences.

Akebia quinata can be considered as one of the best of these vines
for foliage. Its palmately compound leaves are semi-evergreen, and
its small purplish colored flowers— though not conspicuous — are most
interesting and unusual. Akebia trifoliata ( A. lobata) has three leaflets
instead of five and is somewhat coarser in texture because of this char¬
acter. There is a vigorously grown g hybrid (A. pentaphylla ) between
the two now growing in the Arboretum. This plant has leaves with

three, four, and five leaflets. All three have tuberous roots, are easy
to divide and of very vigorous growth once they become well estab¬
lished. When not allowed sufficient space in which to expand, the
foliage becomes so dense that some of the inner leaves are shaded to
such an extent that they often become yellow and drop off.

The bower actinidia ( Actinidia arguta) is perhaps the most vigorous
of all these climbers (actually Pueraria thunbergiana is, but this plant
is not winter-hardy at the Arnold Arboretum). The sexes are sepa¬
rate, and the pistillate plant bears fruits that are about the size of a
gooseberry and very good for making jelly. At one time the Hicks
Nurseries at Westbury, Long Island, had five strains of this species
selected primarily for their large fruits. These are now represented
in the collections at the U. S. D. A. Bureau of Plant Introduction
Station, Bell, Maryland. Actinidia poly gama is another climber, very
enticing to cats. Several plants have been literally chewed to death
in our vine collection. A few years ago Mr. Judd grew some in the
greenhouse for a time, and he states that cats were so attracted by
the delicious odor from this plant that they actually crept through the
overhead greenhouse ventilators to get a taste of it. This vine is rel¬
atively rare in American gardens and if grown should be protected
by wire screening of some sort.

Two species of Celastrus are commonly used, Celastrus scandens , na¬
tive to the United States, and C. orbiculata, ( C. articulata) native to
Japan and China. Both are excellent for their ornamental fruits, and
vigorous twining habit of growth. The peculiar C. flageUaris from
northeastern Asia makes an unusually effective barrier because it has
stipular spines that are very effective indeed. It is the only hardy
twining vine with thorns that thrives with us and consequently should
have many uses. ( Smilax also has thorns, but this is not considered
to be a twining vine). This Celastrus is perfectly hardy in the Arbo¬
retum and might very well be tried elsewhere.

The common moonseed ( Menispermum canadense) is a vigorous twin¬
ing vine that spreads rapidly over the ground and quickly climbs up
any means of support with which it comes in contact. It easily be¬
comes a pest, for it escapes its bounds rapidly, but is not as bad in this
respect as M. dauricum; it should be used with some discretion. These
vines are not very woody and usually die down to the ground in win¬
ter, but on the trellis in the Shrub Collection, some of the vines have
already grown as much as eight feet high this spring alone.

The two silkvines ( Periploca graeca and P.sepium) suffer winter in¬
jury frequently here in the Arboretum. The Grecian silkvine ( P.

graeca) is the taller growing of the two, has more foliage, but is not
as hardy as the Chinese silkvine ( P.sepium ). Their fruits are long
pods, which, when they open in the fall, are full of fluffy seeds re¬
minding one of the milkweed.

There are actually 36 named wisterias growing in the Arboretum.
The differences between some of the varieties of W .floribunda may
not be very marked, but most of these forms are being offered in the
nurseries of the United States. In the Chinese wisteria the flowers of
each cluster open at once, while in those of the Japanese wisteria the
flowers open progressively from the base of the long cluster to the end.
Both are good plants, with deliciously fragrant flowers, the Chinese
form being more common in landscape use, although the W .floribunda
is somewhat hardier. It is from specimens of our native W.fridescens
that this genus was first named by Nuttall in 1818. Seeds of the Jap¬
anese wisteria were first sent to this country by Dr. George R. Hall,
to his friend Samuel Parson, of Flushing, Long Island, in 1862.
Today ‘‘wisteria” and W. sinensis are synonymous to many Ameri¬
cans, but nurserymen are beginning to offer some forms of the Jap¬
anese wisteria with long racemes, so that it will not be long before
these also become familiar.

It may be of interest to Bulletin readers to note in which direction
the various vines twine. One of the catch questions in many a quiz
on garden matters centers on this interesting point. There is not a
haphazard method of twining, but the plants of each species invariably
twine consistently in one direction. In training young vines, this
should be kept in mind, for it is just as easy to wind young plants
around their supports in the right direction, and the chances are that
this will be much more likely to be permanent. I have just now in¬
spected all the vines listed here and have noted their habit in this
respect. It will be seen that the species of each genus consistently
twine in the same direction in all cases, except the wisterias. Three
species of this genus twine by climbing from left to right, and two
species twine by climbing in the opposite direction (i.e., from right
to left). All our plants at the Arboretum have been examined in this
respect, and in the case of W .floribunda two plants of more than a
dozen examined were found that twined in the opposite direction from
the majority of this species. Consequently we should welcome corre¬
spondence on this subject particularly if some plants of the species
named are found which do not twine in the manner noted below.

TWINING VINES

Twining by climbing from left to right

Actinidia polygama

4 4

purpurea

melanandra

kolomikta

arguta

Akebia pentaphylla
trifoliata
quinata

Aristolochia durior

kaempferi
manshuriensis
Celastrus flagellaris
“ orbiculata
seandens
loeseneri
hypoleuca

Menispermum canadense
dauricum
Periploca graeca

4 4

sepium

Wisteria frutescens

macrostachya

Silvervine
Purple Actinidia

Kolomikta
Bower Actinidia

Threeleaf Akebia
Fiveleaf Akebia
Dutchman’s Pipe

Korean Bittersweet
Oriental Bittersweet
American Bittersweet

Common Moonseed
Asiatic Moonseed
Grecian Silkvine
Chinese Silkvine
American Wisteria
Kentucky Wisteria

Twining by climbing from right to left

Berchemia racemosa
Dioscorea villosa
Lonicera henryi

japonica halliana

4 4

sempervirens
Schisandra chinensis
^Wisteria floribunda

4 4 /*

tormosa

Japanese Supplejack
Wild Yam
Henry Honeysuckle
Hall’s Honeysuckle
Trumpet Honeysuckle

Japanese Wisteria

(W. sinensis XW, floribunda)

’’'Of about fourteen plants of this species examined, all but two
twined by climbing from right to left. Those two twined by climbing
from left to right! The experiences of others are welcomed on this
interesting and often controversial subject.

[36]

Donai.d Wyman

ft

ARNOLD ARBORETUM

HARVARD UNIVERSITY

ijr

BULLETIN

OF POPULAR INFORMATION

we* y**k

Series 4. Vol. VII JUNE 30, 1939 Number 8

INDEX KEWENSIS IN IMPROVED LOOSE
LEAF LEDGER FORM

IN 1932, at the New York Botanical Garden, I initiated the past¬
ing of all the entries in Index Kewensis and its seven supplements
then published, in loose leaf ledger form, the first time that the task
was consummated on the basis of modern business technique in any
institution. The actual work was done under the personal supervision
of Mr.G. L. Wittrock, by assistants provided by the Emergency Work
Bureau of New York City. Since the New York set was completed
two additional supplements have been issued. This fundamental work,
now consisting of over 6,000 folio pages with about 700,000 binomial
entries is the most used single work in all institutions where system¬
atic botanical work is a major activity. The importance of a single
generic sequence is at once realized when one considers that if the
several addenda and emendanda be included, there are as many as fif¬
teen different generic entries in the eleven volumes now published
for some groups. This means that one must, or should, search in fif¬
teen different places when consulting the work when one is interested
in determining whether or not such and such a specific name lias been
used, and if so, where it was first published.

In February, 1939, the task of pasting up all entries in the original
work and its nine supplements in one generic sequence was initiated
at the Arnold Arboretum and was completed early in June. The im¬
provements in the Arnold Arboretum set over the style selected at
New York are in the adaptable auto-flex four post binders manufac¬
tured by the Wilson-Jones Company, pig skin binders rather than
buckram being selected for permanency ; chain lock mechanism for
holding the sheets firmly in place and providing for future easy addi-

[37]

tions of extra sheets ; the individual sheets reinforced by tough cloth
strips on the binding edge; and a very much greater amplification of
the pasted-in data, thus providing jfmple space for future additions
without breaking sequences as additional quinquennial supplements
appear; and in the case of all large genera, an indefinite amount of
space for this purpose.

In preparation for this work two complete sets of Index Kewensis
and its nine supplements were clipped. Each entry was stamped “IK”,
“IKS1 ”, “IKS2”, etc. , and when this part of the task was completed,
the clippings were arranged alphabetically under the generic heads,
and chronologically in accordance with the sequence of the several
supplements. After carefully checking for alphabetic sequences and
proper spacing between entries, the items were pasted on the stand¬
ard sheets selected. The estimated amount of space for future addi¬
tions under each small genus was approximately determined by scan¬
ning the several Supplement entries, but all large and medium sized
genera were left “hanging” for indefinite future additions, the blank
part of the last page to be filled first and then new sheets, as neces¬
sary, to be inserted. In all large genera the entries were pasted in
solid, covering both sides of the sheet, regardless of the amount of
space left on any last page, but except for such groups the items were
pasted on one side of the sheet only. Thus in one of the open loose
leaf ledger books shown in the illustration, it will be noted that the
third and last page of Gladiolus is nearly full; but when the tenth
supplement appears, the small amount of remaining space will be
used and then a new sheet will be inserted to take the remainder «nd
future additions.

When Supplement ten appears, five years hence, it may be neces¬
sary to break sequences to provide for some of the newly published
genera, and occasionally it may be necessary to do this in a few cases
where a very large number of new binomials under any old generic
name may be published. The breaking of sequences can, however,
be readily obviated by steaming the sheets, removing the pasted en¬
tries, and expanding the arrangement to meet future contingencies.
This provision for the insertion of additional sheets is the great ad¬
vantage of the modern loose leaf ledger format over the older system
of permanently bound volumes, such as that initiated at Kew many
years ago. The system of a single sequence is, for practical purposes,
superior to the form used at the Rijks Herbarium, Leiden, where the
generic entries were first sorted into families, and then arranged al¬
phabetically by genera, each genus commencing a new page.

[38]

,<S bt

The page size selected is the same as for the New York set, 17 by
14 inches, four column format. The sheets are arranged in one generic
sequence occupying six binders, each about five and one-half inches
thick, about 550 sheets to a binder. The net advantages to the nu¬
merous users of this indispensable work is the actual saving of a vast
amount of time when one has to check the published binomials in
any genus of flowering plants, the time actually saved in this connec¬
tion often amounting to as high as 90 percent.

E.D. Merrill

NOTES

The loose leaf ledger system is ideally adapted to the purpose of
keeping scattered bits of information together and in order. Various
sizes of binders are available from the Wilson- Jones Company, 100
S.Elmora Avenue, Elizabeth, New Jersey. A special glue, known as
“Mikah” remoistening gum, manufactured by the National Adhesive
Corporation, 15 Elkins Street, Boston, Massachusetts, was used in
pasting, and its excellent adhesive qualities make it most satisfactory
for this type of work. This adhesive has been used by the Arboretum
in some other extensive pasting work which is in perfect condition
years after being applied. In making the references of the voluminous
Index Kewensis thus quickly accessible, Dr. Merrill investigated a
considerable number of adhesives, most of which he discarded as being
unsatisfactory for one reason or another. Horticulturists in general
might well profit from Dr, Merrill’s experience and adopt some stand¬
ard loose leaf binder as a highly satisfactory method of filing miscel¬
laneous articles, reports, clippings, notes, programs, and the thousand
and one other bits of garden information that are constantly appear¬
ing and should be kept — provided they can be filed so they are readily
accessible when needed.

Donald Wyman

Addition to Twining Vines (Bulletin of Popular Information, Vol.
7, No. 7, June 23, 1939).

In the lists of twining vines on page 36 the Chinese Wisteria ( Wis¬
teria sinensis) was unfortunately omitted. This should be added to the
group Twining by climbing from left to right.

D. W.

[40]

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF POPULAR INFORMATION

Series 4. Vol. VII AUGUST 11, 1939 Number 9

DROUGHT AT THE ARBORETUM

THE extended drought of the past six weeks has been broken —
we hope ! Never before in the history of the Boston Weather Bu¬
reau was there so little rain in July, and accurate records have been
kept in this area 121 years. Friends of the Arboretum will be glad
to know that the heavy thunderstorm of August fourth, brought con¬
siderable relief to the many plants at the Arnold Arboretum, and
alleviated the acute condition for the time being, at least.

In any large area the size of the Arboretum, there are always places
which can normally be expected to become considerably dry when
rainfall is low- — particularly in the summer time. In the Arboretum,
for instance, one of the azalea beds along the Meadow Road is always
among the first to suffer from lack of water. Some of the plants in the
Chinese collection on Bussey Hill can be expected to show lack of
water readily, and it is usually necessary to water the rhododendron
collection at least once during the summer, although efforts are made
annually to incorporate more humus into the soil about the plants.

There is a rain gauge in the small nursery adjacent to the green¬
house and readings are taken there daily for the Boston Weather Bu¬
reau. Though the official rainfall for the month of July for the Boston
area was given as .75 of an inch (nearly 3 inches below normal) only
.34 of an inch was recorded at the Arboretum during the same period,
about the lowest of any area in the vicinity of Boston. The previous
July record low for rainfall in the Boston area was in 1849 when only
.85 of an inch was recorded.

With an excess of rain ( 1 1 . 10 inches total rainfall in July) and
flooded conditions throughout Massachusetts for the same period last
year (later followed by a hurricane), it would seem that the plants in
eastern Massachusetts are being subjected to all the vagaries which
an unpredictable Nature can provide in the short period of one year!
It is fortunate, indeed, that the heavy rainfall of August fourth came

LffiftA*?

IWW YOKK
©otanical

when it did. The rain gauge recorded a fall at the Arboretum of .99
of an inch, practically three times as much rain as had fallen during
the entire month of July!

Plants Affected

Foremost among the plants which showed noticeable wilting were
the large lilacs in the lilac collection growing between the walk and
the road, and the Philadelphus on the opposite side. These were
wilting consistently and it became necessary to water them every few
days in order to keep them from losing their leaves. The rhododen¬
drons were beginning to show wilting about the middle of July. Be¬
cause of the great value of these plants it was necessary to water
them continuously for a full week.

Many of the younger trees and shrubs planted in the collections
during the past two and three years suffered considerably. Attempts
were made to water them but some were so far from the road that it
was impossible and as a consequence some undoubtedly will die.

Near the end of July, particularly during the last few days, trees
began to show the effects of drought at an alarming rate. Some of the
small Japanese cherries near the Administration Building dropped
some of their leaves. Several of the viburnums in the collection were
in very poor condition, and such rugged plants as Viburnum dentatum
and V. lenlago, growing at various places in the Arboretum showed
an increasing number of wilted and fallen leaves. The bank of For-
sythias below the lilac collection started to wilt about July thirty-first.
It was nothing serious, for the leaves did not dry up entirely as did
those of many other plants, but they did show pronounced wilting and
the rain came in the nick of time to save them from more serious
injury.

Fires

During the latter part of July the danger to the plants from fire
Avas as great as the danger from lack of water. One day during the
last Aveek of July there Avere three fires within the boundaries of the
Arboretum, tAVo of them burning simultaneously. Most of the fires,
(they averaged about one a day for over two Aveeks) Avere small grass
fires, started by dropped matches or cigarettes and were easily con¬
trolled by Arboretum Avorkmen, but for some it Avas necessary to call
the fire department in order to obtain quick control. No serious dam¬
age Avas done to any of the valuable trees and shrubs, due to the
prompt control methods of the Arboretum force and the firemen.

It is hoped that the heavy rains of August fourth will be folloAved
shortly by others. At the time this is Avritten, plants in the Arbore¬
tum can be said to have recuperated fairly well, but with a pronounced
deficiency of rainfall to date, considerably more rain is needed before
the trees and shrubs can be considered safely out of danger for the
rest of the summer.

[4-2]

Logs awaiting the saw mill in Tom Swamp Pond of the Harvard Forest, Petersham, Mass., mute
evidence of the terrific destruction caused by the hurricane last fall. One might judge that Nature
had run through the entire gamut of weather tricks since July of last year.

An Important Introduction of Seeds from Western China
to the Arnold Arboretum

Within the past few years it has been the policy of the Arnold
Arboretum to make modest grants to strategically located institutions
and individuals in support of cooperative collection of seeds as well as
botanical specimens essential to the proper identification of the form¬
er. Last year the very large seed collection, comprising about 2300
numbers, made by Mr. Yu in 1937 in western China was distributed
through the Arboretum. From a grant made in the early part of 1938
to the Fan Memorial Institute of Biology in Peiping the Arboretum
has just received, in one shipment, 585 packages of seeds from Yun-
nan-Sikang, in southwestern China. Over one-half of the numbers
represent woody species, the remainder herbaceous forms. The field
work was done by Mr.T.T.Yu during the past collecting season. The
seeds were shipped from Yunnan-fu in April and delivered in Boston
on July 12, a commentary on the delays in transportation to which
such material is subject due to present unsettled conditions in China.
The botanical material, shipped at the same time, has not yet been
received.

Selections from the woody species will be made for trial at the Ar¬
boretum, while excess material will be distributed to the various cor¬
respondents of the institution who may be interested in new intro¬
ductions. With little information as to whether or not the various
species may prove to be hardy in New England, it seems to be better
policy to give such current introductions rather wide distribution, so
that if the species fails to survive with us, it may be found to thrive
elsewhere.

The seeds of the herbaceous species, mostly determined to the ge¬
nus, have been turned over to the Massachusetts Horticultural Society
for distribution to its members. This current shipment from war-torn
China is potent evidence that plant hunting is still actively going on
in these unsettled times.

Note

The Arboretum is always recommending new plants to the horti-
culturally minded public, though it is not always, possible to get such
new things in large quantity. Both Privsepia sivevsis and P. uniflora
are two excellent, vigorous-growing, thorny shrubs which are not grown
much in this country outside of botanic gardens but they have been
described from time to time in this Bulletin and recommended. The
trouble has been the inability to get seed. Now it may be obtained
for $0.50 per pound (cleaned, packed, and delivered to the Post Office
at Harbin, Manchoukuo) from:

Mr. A. Woeikoff, The Garden of Manchurian Flora, P. O. Box 33,
Harbin, Manchoukuo. Those interested should write immediately.

Donald Wyman

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF POPULAR INFORMATION

YO^Ui

botanical

WAilDEN

Series 4. Vol. VII NOVEMBER 3, 1939 Number 10

SALT WATER INJURY OF WOODY PLANTS RESULTING
FROM THE HURRICANE OF SEPTEMBER 21, 1938

SINCE last year’s Hurricane, it has been particularly interesting
to note the rapidity with which certain trees and shrubs recovered
from salt water injury. Many plants have shown a remarkable ability
to withstand immersion in salt water for twenty-four hours and longer.
Because of this, a study was made of certain sections around Woods
Hole and Falmouth, in Massachusetts; Newport, Rhode Island; and
places along the north shore of Massachusetts, a year after the hurri¬
cane, in an attempt to see how well injured plants were recovering.
As a result of these observations, the appended lists are presented.
These data were compiled on special trips to the areas indicated and
have been checked by several individuals who have been doing land¬
scape work in the regions. Mr. Wilfred Wheeler, of Hatchville, Mass¬
achusetts, has been particularly observant and helpful, and assisted
materially with his important observations and has also checked the
lists.

Lawns

Many lawns were flooded with salt water, and in the spring anxious
property holders sent many soil samples to the Rhode Island Exper¬
iment Station for analysis. Several of these samples were analyzed but
jn no case was a sufficiently heavy accumulation of salts found to cause
permanent injury to the soil. No great accumulation of salt in the soil
took place because the ground was thoroughly saturated with water
before the storm struck. It had been raining steadily during the four
days preceeding the storm, and in the months following there was
plenty of rain and snow, so that much of the salt remaining after the
storm was leached out before spring. However, there were many cases

where either the grass foliage or the grass roots or both were killed.

Standard practice for renovating immersed lawns was to apply
ground limestone at the rate of 20-50 pounds per thousand square feet
and thoroughly water the areas after the limestone was applied. If the
grass roots were not killed, new growth appeared in the spring. If the
grass roots were killed, the soil was dug up and the affected areas were
reseeded, standard applications of regularly recommended fertilizers
being made at the same time. Different grasses reacted in different
ways. Bent grass and Kentucky Blue grass were easily killed, while
the omnipresent crabgrass eventually appeared even after being sub¬
merged 24 hours or more. Several areas around Woods Hole where
salt water had stood for 24 hours, observed one year later, were a good
green — from a distance. On close examination, the grasses and weeds
making this green color were of some of the coarser and more objec¬
tionable sorts, but, nevertheless, the fact remains that they were not
killed and made an excellent recovery.

Trees and Shrubs

Although considerable care was taken in observing the extent of
salt water injury on trees and shrubs, conditions differed widely, and
plants that may have suffered severe damage in one place may have
been unharmed in others. This may be on account of variations in soil,
drainage, and the length of time the salt water stood about the plant
roots. Salt-spray injury also differed widely, perhaps chiefly because
of varying degrees in exposure, wind velocities at the time of the storm,
height, age and condition of the plants, and other factors.

Consequently, the information included herein should be taken only
at its face value. It merely represents observations made in areas where
salt water damage to woody plants was greatest. Many commonly
grown plants were not observed in the flooded areas examined ; con¬
sequently numerous additions to the lists can and should be made as
additional data becomes available. Fortunately, with hurricanes in the
east spaced 100 years apart, it is not necessary that the fear of another
in the immediate future should govern present seashore planting. Since
continual planting is being done, it is hoped that the following lists
may prove helpful to those engaged in selecting the right kind of plant
material for exposed seashore situations. It is very seldom that such
a golden opportunity is offered to study the effects of wide-spread salt
water damage to woody plants, and, since the opportunity has pre¬
sented itself, it was thought advisable to take advantage of it and make
careful notes on individual species before the damage became mini¬
mized by the soothing effects of time.

[ 46 ]

PLATE VIII

Pictures taken in Eel Pond swamp, Woods Hole, September 29, 1939.

At the top, Sycamore maple, Acer pseudoplatanus is growing unharmed though its
roots were submerged with salt water for 24 hours. Nearby, red maple, elm and birch
have been severely injured.

Lower picture shows red maple and Pinus rigida killed, while white willow, bayberry,
azalea and various grasses are growing well.

The following plants were submerged in salt water for at
least 24 hours after the hurricane and were recovering
satisfactorily when observed one year later.

(in all cases the roots were submerged, and in many cases the
plants themselves or portions of them. Satisfactory recovery means
that, although injured, these plants were sending out vigorous suckers
from the base or from the larger stems, or the tops were sending out
new shoots. It should be noted here that if the inundation had come
after a long drought and the soil had not been saturated with water,
there might have been a considerably greater injury.)

Acer pseudoplatanus
Aesculus hippocastanum
Ailanthus altissima
Aronia arbutifolia
Calluna vulgaris
Campsis radicans
Catalpa speciosa
Clematis paniculata
Clethra alnifolia
Comptonia asplenifolia
Corylus americana
Cryptomeria japonica
Hibiscus syriacus
Ilex glabra

Juniperus ehinensis pfitzeriana
Juniperus virginiana
Juniperus virginiana glauca
Ligustrum amurense
Ligustrum ovalifolium
Malus sylvestris
Myriea pensylvanica
(M. earolinensis)

Nyssa sylvatica
Farthenocissus tricuspidata
Fopulus grandidentata
Ficea canadensis
Picea pungens kosteri
Finus sylvestris
Pinus thunbergi

Prunus martima

Prunus serotina

Prunus virginiana

Pyrus communis

Quercus alba

Rhododendron viscosum

Rhus aromatica ( R. canadensis)

Rhus copallina

Rhus glabra

Rhus toxicodendron

Rhus typhina

Rhus vernix

Robinia pseudoacacia

Rosa (Ramblers)

Rosa rugosa
Rosa virginiana
Rosa wichuraiana
Salix alba

Sambucus canadensis
Smilax glauca
Spiraea prunifolia
Tamarix parviflora
Tilia cordata
Ulmus pumila
Vaccinium corvmbosum
Viburnum dentatum
Vitis labrusca
Wisteria sinensis

[ 18.]

1

PLATE IX

The Japanese Black Pine (P.thunbergi) was outstanding in its resistance to
salt water. This one, only a few hundred feet from the shore at Woods Hole,
was exposed to the worst of salt spray and was even covered with salt water,
yet it came through in perfect condition.

Plants subjected to salt spray and either uninjured
or not injured seriously

(The hurricane came only a few weeks before most deciduous trees
dropped their leaves; consequently, salt spray injury was comparative¬
ly worse on the evergreens. The amount of salt spray varied consid¬
erably in different locations, and many of the plants in this list would
be injured in one place and uninjured in another. Many other plants
may have weathered salt spray injury satisfactorily but do not appear
on this list because they were not observed. These facts should be
kept in mind when studying the list.)

Acer platanoides
Acer pseudoplatanus
Actinidia arguta
Ailanthus altissima
Amelanehier canadensis
Arctostaphylos uva-ursi
Baccharis halimifolia
Cedrus atlantica glauca
Cephalanthus occidentalis
Chamaeeyparis pisifera plumosa
Chamaecy paris pisifera squarrosa
(damaged somewhat)

Clethra alnifolia
Crataegus crus-galli
Cytisus scoparius
Elaeagnus angustifolia
Elaeagnus longipes
Fagus sylvatica
Forsythia species
Hippophae rhamnoides
Hydrangea macrophylla
(H. hortensis)

Ilex glabra
Ilex opaca

Juniperus communis
Juniperus communis depressa
Juniperus exeelsa stricta
Juniperus horizontalis
Juniperus virginiana
Juniperus virginiana glauca

Kalmia angustifolia
Ligustrum amurense
Lonicera japonica halliana
Lonicera morrowi
Lonicera tatarica
Malus sylvestris
Myrica pensylvanica
(M. carolinensis)
Parthenoeissus tricuspidata
Physocarpus opulifolius
Picea abies
Picea asperata
Picea canadensis
Picea glauca
Picea orientalis
Picea pungens kosteri
Pieris japonica
Pinus mugo mughus (varied
responses on different soils)
Pinus nigra
Pinus thunbergi
Populus alba
Prunus maritima
Pyrus communis
Quercus marilandica
Rhamnus cathartica
Rhus copallina
Rhus glabra
Rhus toxicodendron
Rhus typhina

[50]

Robinia pseudoacacia
Rosa (ramblers)

Rosa blanda
Rosa humilis
Rosa nitida
Rosa rugosa
Rosa virginiana
Rosa wichuraiana
Salix humilis
Sambucus canadensis
Spiraea species

Syringa vulgaris (if submerged,
it whs k. died)

Tamarix parviflora

Taxus species and varieties (even
took submergence for 2—3
days in some instances though
they did not respond as well
as Pfitzer’s juniper).

Tilia americana
Tilia cordata
Tilia vulgaris

Thuja occidentalis varieties
Ulmus pumila
Vaccinium corymbosum
Viburnum cassinoides
Viburnum dentatum
Wisteria sinensis

Plants killed or very seriously injured by salt water

(if salt water stood on the soil long enough it would kill all the
roots of most trees and shrubs, except a very few like Baccharis. The
plants listed below were killed or seriously injured by salt spray, by
submergence in saltwater, or by both.)

Abies concolor
Abies pinsapo
Acer rubrum

Azaleas (evergreen types)
Berberis thunbergi
Betula papyrifera
Betula populifolia
Buxus sempervirens
Buxus sempervirens suffruticosa
Cephalanthus occidentalis
Chamaecy paris species and
varieties

Clematis virginiana

Euonymus species and varieties

Ginkgo biloba

Hedera helix

Larix decidua

Liquidambar styraciflua

Liriodendron tulipifera

Lyonia ligustrina
Parthenocissus quinquefolia
Pinus rigida
Pinus strobus
Pseudotsuga taxifolia
(P. douglasi)

Rhododendrons (evergreen
types)

Rosa — (Any grafted or budded
rose) Injury may have been
due to sudden freeze late in
the fall, more than to salt
water injury.

Sassafras albidum (S. officinale)
(but coming up from roots)
Tsuga canadensis
Ulmus americana
Ulmus fulva

Weigela species and varieties

NOTE

Through the support received from a number of friends of the
Arnold Arboretum it has been possible to establish a Fellowship for
1939-40 which has been assigned to Miss Luetta Chen, a Chinese
student taking graduate work in botany in Radcliffe College. This has
been designated the “George B. Emerson Fellowship” in memory of
Mr. Emerson, one of the trustees of the James Arnold estate, and the
individual who actually suggested the establishment of the Arnold
Arboretum. Because of his enthusiasm and interest, the trustees of
the Arnold estate were inspired to transfer the initial endowment of
$100,000 to Harvard University, provided the University would set
aside a part of the Bussey farm as a site and foster the establishment
of the Arnold Arboretum.

Donald Wyman

[52]

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF POPULAR INFORMATION

Series 4. Vol. VII NOVEMBER 29, 1939 Number 11

THE ORDER OF BLOOM OF TREES AND SHRUBS
AT THE ARNOLD ARBORETUM

IN order to establish a beautiful planting of flowering trees and
shrubs, one must have a knowledge of those plants which effec¬
tively bloom together. Although the actual day on which a certain
plant may come into bloom varies from year to year according to the
weather, there are some that always bloom together, and it is this
information that gardeners should always have available when planning
their gardens. In this bulletin a large number of the more ornamental
trees and shrubs growing at the Arboretum are listed according to
their sequence of bloom. Many varieties have been omitted because
of lack of space, but the list is of sufficient length to serve as a basic
list to which future additions may be made. Of particular interest could
be the addition of notes on the length of bloom of these plants, and
in making additions and notes of this character the list should become
of increasing value.

Many have had the opportunity of following the spring from the
South into the North. In fact, one could enjoy the beauties of any
particular period in the spring a full three months simply by travelling
in slow stages from Florida to Maine. The following schedule shows
the approximate times the mountain-laurel ( Kalmia lalifolia) blooms
at different places in the United States. Though these vary according
to the weather during the particular year in question (see Bulletin,
No. 3, April 29, 1939, page Id, for other information on this same
point) , nevertheless, there is a progressive display of mountain-laurel
from the South to the North over a two-month period.

The time Kalmia latifolia blooms in different regions

Augusta, Georgia . Mid April

Glen St. Mary, Florida . Late April

Monongahela National Forest, West Virginia . Mid May

Shenandoah Valley, Virginia . Mid May

St. Louis, Missouri . Late May

Philadelphia, Pennsylvania . Late May

New York, New York . Early June

Columbus, Ohio . Early June

Chicago, Illinois . Mid June

Rochester, New York . Mid June

Boston, Massachusetts . Mid June

Seattle, Washington . Late June

Since most of the hybrid rhododendrons bloom slightly before the
mountain-laurel and most of the Philadelphus species and varieties bloom
at about the same time, it is easy to correlate the time of bloom of
other plants with those in such a list. With this in mind, the list of¬
fered in this bulletin is really applicable anywhere since the sequence
of bloom is the same, even though the actual time mentioned is for
the vicinity of Boston, Massachusetts.

In consulting the following list it should be kept in mind that,
though a certain plant may be listed as blooming the first part of June,
it may remain in full bloom and hence be effective from the landscape
point of view for at least two weeks or more, and so can be used in
combination with plants that normally bloom later. The length of
bloom is an intensely interesting study, and because of a long blooming
period, many plants are quite useful. As an example Spiraea prunifolia
plena normally starts to bloom at the Arboretum on May ] . It fre¬
quently remains effective for three full weeks. On the other hand, a
plant like Amelanchier canadensis may remain in bloom only five days
or even drop its petals in three days if the weather is unusually warm.
Consequently, the length of time the flowers remain on the plant is
important and depends upon the weather and the kind of plant. As
a rule, the plants with double flowers last considerably longer than
do those varieties with single flowers.

The length of time that plants like the flowering crabapple can be
enjoyed depends particularly upon the weather. Many are more in¬
teresting in bud than in full flower, and if there is a long period of
cool, cloudy weather when the buds are full but not open, they may
remain in good condition for some time and so may be colorful and

[54]

effective for two weeks or more. On the other hand, if a warm hot
spell forces the buds to open at once, the flowers may fade in less than
a week. Since these conditions vary considerably, those interested in
using such plants must study them carefully and consider local con¬
ditions as a basis for determining the length of time the flowers may
be expected to be of ornamental value.

Wherever possible, yearly records have been kept of individual
plants, since one individual of the same variety, growing in a warm,
sunny spot, will undoubtedly bloom earlier than another which is
more exposed. The following list is based on blooming dates in Boston
and has been correlated with records kept by Professor J.G.Jack of
the Arnold Arboretum between 1887 and 1893. Because of lack of
space, a majority of the varietal names have not been given. Among
the large number of Japanese cherries and the hybrid lilacs, there are
some varieties that do bloom earlier than others, but this is a study
in itself. Not all the plants listed are of value for their flowers, but
they have simply been included as a matter of record. A plant is listed
only for the particular date when it is in full bloom from the landscape
point of view, although its flower buds might be rather conspicuous
for several days previous to full bloom. As an example Pieris floribunda
and P.japonica are listed only once each in the following list, yet the
flower buds of both are conspicuous a greater part of the late winter.
Consequently, it is not to be considered that hard and fast date lines
are set up in the following list, but the general sequence and the as¬
sociation of plants blooming together should be of particular value to
all interested in woody trees and shrubs.

ORDER OF BLOOM
February

Hamamelis vernalis

March

Acer saccharinum
Hamamelis japonica
Hamamelis mollis

Prinsepia sinensis buds opening
Salix species
(Snowdrop & Crocus)

Early April

Cornus mas
Cornus officinalis

Acer rubrum
Alnus incana

rugosa

Corylus species
Daphne mezereum
Erica carnea
Forsythia ovata
Jasminum nudiflorum

Lonicera fragrantissima
praeflorens
standishi
Pieris japonica

Populus species
Prunus davidiana
Rhododendron dauricum
Viburnum fragrans

Mid-April

Abeliophyllum distich um
Acer negundo

Berberis thunbergi (leaf buds
opening)

Betula species
Cercidiphyllum japonicum
Corylopsis species
Dirca palustris
Epigaea repens
Forsvthia europaea

intermedia vars.
suspensa

Late

Acer circinatum
4 diabolicum purpurascens
“ platanoides
Aesculus species, leaves well
advanced

Euptelea francheti
polyandra

Larix species leaf buds opening
Lonicera altmanni pilosiuscula
coerulea edulis
“ tenuipes
Maddenia hypoleuca
Magnolia denudata
44 kobus

44 borealis
stellata

Malus baccata mandshurica
Myrica gale
Prinsepia sinensis
Prunus apetala
44 armeniaca

Forsythia viridissima
Lindera benzoin
Lonicera morrowi and L.tatarica
leaf buds opening
Pieris floribunda
Rhododendron mucronulatum
Salix blanda leaf buds opening
Shepherdia argentea

canadensis leaf buds

opening

Viburnum sieboldi
Ulmus americana

Prunus canescens
cerasifera

6 6

concinna
44 cyclamina
44 dasycarpa
fenzliana
44 incisa

44 serrata
mandshurica

i i

nigra

nipponica

sargenti

44 salicina
< (

simoni

subhirtella and varieties

tomentosa

tomentella

triloba

yedoensis

Vinca minor and varieties

[56]

Early May

Acer saccharum

Prunus incana

Alyssum gemonense

4 4

lanata

Amelanchier species

4 4

maritima

Andromeda glaucopbylla

4 4

maximowiczi

Chamaedaphne calyculata

4 4

munsoniana

Crataegus arnoldiana

4 4

orthosepala

Chaenomeles japonica

4 4

padus and varieties

Chaenomeles lagenaria vars.

4 4

persica

Cydonia oblonga

4 4

serrulata (many double

Cytisus beani

flowered forms starting to

decumbens

bloom and continuing for two

elongatus

weeks at least, depending on

Daphne cneorum

the variety, some being slight¬

(Dandelion)

ly earlier than others.)

Forestiera acuminata

Prunus slavini

Iberis tenoreana

Pyrus

amygdaliformis

Ledum groelandicum

4 4

communis and varieties

Leitneria floridana

4 4

michauxi

Lonicera canadensis

4 4

serotina

coerulea

4 4

salicifolia

gracilipes

Rhododendron mucronatum

saccata

venstum

Magnolia salicifolia

Ribes

alpestre

Magnolia soulangeana vars.

4 4

alpinum

Malus astracanica

4 4

aureum

44 brevipes

4 4

diacantha

44 micromalus

4 4

gordonianum

Mahonia aquifolium

4 4

inebrians

(Narcissus)

4 4

irriguum

Nemopanthus mucronata

4 4

odoratum

Phlox subulata

4 4

orientale heterotrichum

(Primula elatior superba)

4 4

pinetorum

( 44 polyantha)

4 4

robustum

Prunus allegheniensis

4 4

setosum

americana

4 4

tenuipes

avium

Spiraea arguta

cerasus

4 4

chamaedry folia ulmifolia

domestica

4 4

hypericifolia acuta

fontanesiana

4 4

media

hortulana

4 4

multidora

[57]

Spiraea pikoviensis

44 prunifolia
6 6 6 6 ,

plena

thunbergi

(Tulips)

Vaccinium species
Viburnum alnifolium

Viburnum bitchiuensis
buddleifolium
burejaetieum
shensianum

(Violets)

Xanthorhiza simplicissima

Zanthoxylum americanum
Mid-May

Aesculus carnea

hippocastanum
Akebia lobata
quinata

Alyssum gemonense
saxatile

Amelasorbus jacki
Aristolochia mandshuriensis
Aubretia deltoidea
Berberis dictyopbylla
dielsiana
stenophylla
thunbergi
Berberis vulgaris
Calycanthus floridus
Caragana species
Cercis canadensis
“ chinensis
Coriaria japoniea
Cornus florida
Coronilla emeroides
Cytisus praecox
purgans
purpurea
ratisbonensis
rocheli
scoparius
triflorus

Daphne caucasica
cneorum

Elaeagnus multiflora
Enkianthus perulatus
Euonvmus alata

Exochorda giraldi

korolkovi
macrantha
grand iflora

6 6

racemosa

Forestiera neo-mexicana
Fothergilla species
Halesia Carolina
monticola
Kerria japonica

Lonicera

alpigena

6 6

gibbiflora

6 6

microphylla

6 6

muendeniensis

6 6

muscaviensis

6 6

syringantha

6 6

wolfi

6 6

thibetica

6 6

xylosteum

Magnolia fraseri

liliflora nigra
Malus adstringens
“ arnoldiana
atrosanguinea
44 baccata
44 denticulata
44 floribunda
44 glabrescens
44 halliana parkmani
44 hupehensis
44 prunifolia
44 pumila niedzwetzkya
44 purpurea

[58]

Malus

robusta

R.yedoense poukhanense

4 4

sieboldi

Rhodotypos scandens

4 4

soulardi

Rhus canadensis

4 4

spectabilis

Ribes fascieulatum

4 4

zumi calocarpa

4 4

sangumeum

Pachysandra terminals
(Papaver orientale)

Potentilla fruticosa friedrichseni

Prinsepia uniflora

Prunus angustifolia watsoni

glandulosa and varieties

4 4

grayana

4 4 . ....

instititia

maacki

4 4

mexicana

persica, double flowered
varieties

pumila susquehanae
sieboldi

4 4 ...

virgmiana
Quercus species
Rhododendron canadense
4 4 carolinianum
“ fraseri

44 obtusurn amoenum
44 obtusum arnoldianurn
44 obtusum 4 ‘Hinodegiri”

44 obtusum kaempferi
44 reticulatum
44 schlippenbachi
44 vaseyi

Late

pinetorum
Rosa primula
Sambueus pubens
Sibiraea laevigata
Spiraea canescens

4 4

gemmata

hypericifolia

inflexa

mollifera

oxyodon

pubescens

Syringa hyacinthiflora vars.
oblata dilatata
44 giraldi
pinnatifolia

vulgaris; with approxi¬
mately 300 varieties. It is im¬
possible to list them here as
“Early,” “Medium or
4 4 Late,” though some might
be so listed.

Viburnum carlesi
lantana
mongolicum
wrighti

Weigela “Fleur de Mai”

May

Acer ginnala
Aronia arbutifolia
Assimina triloba
Berberis amurensis
julianae

4 4

vernae

verruculosa

vulgaris

(Buttercup)

Ceanothus ovatus
Celastrus species
Chaenomeles lagenaria
“Kermisina semiplena”
Cornus alternifolia
44 controversa
44 stolonifera
Coronilla emeroides
Cotoneaster adpressa

[ 59 ]

Cotoneaster multiflora
racemiflora
Crataegus oxyacantha

4 4

pruinosa
punctata
Daphne giraldi
(Daylillies)

Deutzia candelabrum
gracilis
hypoleuca
lemoinei & varieties
parviflora

rosea and varieties
Elaeagnus longipes
umbellata

Enkianthus campanulatus
deflexus

Fendlera wrighti
Genista pilosa
Iberis sempervirens
Juglans sieboldiana
Leucothe racemosa
Lonicera amoena

bella rosea
chrysantba
korolkowi
maacki
morrowi
punicea

tartarica and varieties
Magnolia cordata
glauca

soulangeana lennei
tripetala
Malus angustifolia
44 bracteata

4 4

coronana

charlottae

dulca

44 glaucescens
ioensis

Malus ioensis plena

4 4

sargenti

spectabilis riversi
sylvestris
scbeideckeri
toringoides
Neilla sinensis
Paeonia suff’ruticosa
Petteria ramentaceae
Philadelphus hirsutus
schrenki
Pbotinia villosa
Physocarpus amurensis

4 4

monogynus

Prunuslaurocerasusschipkaensis

pennsylvanica

serotina

Rhamnus catbartica
Rhododendron atlanticum
R. catawbiense 4 4 Albert”

R. 4 4 4 <Boulede Neige”

R. 4 4 4 4 Cbarles Dickens”

R. “ “Daisy”

R. “ “Mont Blanc”

R. catawbiense “Viola”
R.fortunei “Dukeof York”
R.japonicum
R.gandavense hybrids
R.molle hybrids
R.nudiflorum
R.roseum
R. smirnowi
Robinia elliotti
fertilis
bispida
kelseyi
slavini

Rosa acicularis engelmanni
44 hugonis

spinosissima and vars.

44 xanthina

4 4

4 4

4 4

4 4

4 4

4 4

4 4

[60]

Rubus deliciosus
Smilax rotundifolia
Spiraea blanda
blumei
eantoniensis
chamaedry folia

4 4

cinerea

4 4

nippomca

trilobata

vanhouttei

wilsoni

Staphylea colehica
trifolia

Styrax obassia
Symplocos paniculata
Syringa chinensis
julianae

4 4

meyeri

microphylla

t .

persica

pinetorum

potanini

pubescens

Actinidia arguta
Buddleia alternifolia
Chionanthus retusus

4 4 ...

virgmicus
Cladrastis lutea
Clematis glauca angustifolia
recta

Colutea species
Cornus alba

kousa chinensis
rugosa

Cotinus coggygria
Crataegus cordata

crus-galli
oxyacantha pauli
Daphne pontica
Decaisnea fargesi

Syringa velutina

vulgaris and many vari¬
eties
wolfi

4 4

yunnanensis
Tamarix parviflora
Thymus serphyllum
Vaccinium corymbosum
Viburnum affine

4 4

erosum

lentago

macrocephalum
opulus roseum
rhytidophyllum
rufidulum
sieboldi

4 4

tomentosum

4 4 4 4 , .

plicatum

trilobum

Weigela, several species & many
varieties

Wisteria species and vars.

Early June

Elaeagnus angustifolia
Euonymus atropurpurea
Genista hispanica
Genista tinctoria
Helianthemum nummularium
Hydrangea petiolaris

xanthoneura wilsoni
Idesia polycarpa
Ilex opaca

verticillata
Jamesia americana
Kolkwitzia amabilis
Laburnum species
Leucothoe catesbaei
Lonicera maacki podocarpa
minutiflora
rupreehtiana

Lonicera xylosteoides
Lycium species
Magnolia parvifiora
Phellodendron amurense
Philadelphia sehrenki
Physocarpus amurensis
intermedia
opulifolius

Potentilla fruticosa varieties
Pterostyrax hispida
Rhamnus frangula
Rhododendron arbutifolium

calendulaceum
catawbiense and
many vars.
ferrugineum

R. minus
Rhus potanini
Robinia hartwigi

pseudoaeacia
Rosa acicularis
44 arnoldiana
44 blanda

4 4

camna

4 4 foetida harrisoni

4 4 4 4

persiana
Rosa multiHora

Rosa rugosa

4 4 . .

spinosissima

4( . . .

virgimana
webbiana
willmottiae
Sassafras albidum
Sorbus aucuparia
Spiraea dasyantha
trichocarpa
Staphylea pinnata
Styrax americana

4 4

japonica

Syringa henryi varieties
josikaea varieties
komarowi

4 4

prestonae and varieties
reflexa

4 4

swegmzowi

tomentella

villosa

“ i

wilsoni

Viburnum cassinoides
dentatum
dilatatum
opulus
prunifolium
sargenti

4 4

4 4
4 4

Mid-June

Amorpha fruticosa
Castanea pumila
Catalpa speciosa
Ceanothus pallidus rosea
Celastrus scandens
Colutea arborescens
Cornus amomum

bretschneideri

4 4

coreana

kousa

4 4

racemosa
Cytisus supinus
Deutzia scabra and varieties

Diospyros virginiana
Euonymus europaea

fortunei vegeta

Gynmocladus dioica
Hydrangea bretschneideri
Ilex glabra
Kalmia angustifolia
latifolia

Ligustrum obtusifolium

4 4 4 4 .

regelianum

vulgare

Liriodendron tulipifera
Lonicera browni
iberica

japonica halliana
periclymenum
Periploca sepium
Philadelphus coronarius

cymosus varieties

Philadelphia inodorus

grandiflorus

laxus

lemoinei and
varieties

6 6

maximus

pubescens

6 6

tomentosus
virginalis and
varieties

Rosa arvensis
dahurica
jacksoni
micrantba

multiflora cathayensis
rubifolia

rugosa kamtchatica
6 6 6 6

repens

Rubus allegheniensis
Sophora vicifolia
Spiraea henryi

Acanthopanax sieboldianus

senticosus

Actinidia polygama

Amorpha glabra

Cornus macrophylla

Cotoneaster salicifolia

Cytisus albus
6 6

supinus

Deutzia myriantha
Genista anglica
Halimodendron halodendron
Ilex crenata
Indigofera decora
kirilowi
potanin i
Itea virginica
Lonicera henryi
Periploca graeca
Rhododendron arborescens
Rhododendron maximum
Rhus typhina
Rosa anemoniflora

Spiraea menziesi

nipponica rotundifolia
veitchi

Symphoricarpos racemosus laev-
igatus

Syringa amurensis
6 6 6 6

japomca

pekinensis

Tilia platyphyllos
6 6

tomentosa

Vaccinium stamineum
Viburnum acerifolium

dilatatum hispid um

6 6

erosum

molle

pubescens

Weigela “Congo”

Xolisma ligustrina
6 6

manana

Zenobia pulverulenta

June

Rosa Carolina

damascena

multibracteata

Rubus odoratus

Sambucus canadensis

Schizophragma hydrangeoides

Sorbaria sorbifolia

Spiraea brachybotrys

bumalda

latifolia

p}n-amidata

rubra

sylvestris

tenissima

tomentosa
6 6 ...

virginiana

Watson iana

Stewartia koreana

Tilia species

Tripterygium regeli

Weigela “Eva Rathke”

Yucca glauca

[03]

Buddleia japonica
Castanea species
Cytisus nigricans
Holodiscus discolor
Indigofera amblyantha

Early July

Maackia amurensis
Rhus glabra
Rosa setigera
Spiraea billiardi

Mid-July

Aesculus parviflora

A morph a braehycarpa

fruticosa

Berberis aggregata

Catalpa ovata
6 6

speciosa

Ceanothus arnericanus
Clematis jackmani
Diervilla lonicera
Hydrangea arborescens grandi-

flora

cinera

paniculata praecox

quercifolia

serrata

Hypericum aureum

Late

Hypericum kalmianum
Koelreuteria paniculata
Lespedeza bicolor
Lonicera sempervirens
Martensia erecta
Rhododendron viscosum
Securinega ramiflora
Sorbaria sorbifolia
Sphaeralcea remota
Spiraea alba

albiflora
douglasi
magentae
Tamarix odessana

i i .

pentandra
Yucca filamentosa

July

Albizzia julibrissin rosea
Aralia spinosa
Buddie ia albiflora
Callicarpa species
Calluna vulgaris and varieties
Campsis radicans
Cephalanthus occidentalis
Clethra acuminata
alnifolia

Hydrangea radiata

Hypericum prolificum
Indigofera pulchella
Ligustrum quihoui
Lonicera involucrata serotina
Nandina domestica
Oxydendrum arboreum
Sorbaria arborea
Spiraea bumalda * Anthony
Waterer”

August

Abelia grandiflora
Buddleia davidi magniflca
Clematis virginiana
vitalba
Evodia danielli
Hibiscus syriacus varieties
Hydrangea arborescens
macrophylla
paniculata

Hypericum dawsonianum
Lespedeza buergeri praecox
cyrtobotrya
Lonicera heckrotti
Paulownia tomentosa
Polygonum auberti
Sophora japonica
ymphoricarpos vulgaris
Vitex agnus-castus

negundo incisa

grandiflora

September

Clematis paniculata Elsholtzia stauntoni

Clerodendron trichotomum Franklinia altamaha

October

Hamamelis virginiana

[6-1]

Donald Wyman

ARNOLD ARBORETUM

HARVARD UNIVERSITY

LHUJCAfv’*

tew yo.<&
50TAMJCAI*
Q a

BULLETIN

OF POPULAR INFORMATION

Series 4. Vol. VII DECEMBER 1, 1939 Number 12

BREEDING NEW VARIETIES OF ORNAMENTAL
CRABAPPLES AT THE ARNOLD ARBORETUM

DURING the past few years the Arboretum has started rather
extensive experiments in the breeding of ornamental trees and
shrubs. One of the objectives is the possibility of thus obtaining new
plants which may be desirable from an ornamental standpoint. To
perhaps attain this objective, a large number of seedlings must be
grown from which to make selections. Since nursery space at the Ar¬
boretum is limited, we cannot carry through all of these seedlings to
maturity and, hence, plan to farm out” these plants to interested
individuals who have space in which to grow them. The ornamental
crabapples were selected because of their high ornamental value and
the interesting genetic problems connected with their breeding. Ap¬
proximately 2000 seedlings will be distributed next spring to individ¬
uals and institutions requesting them, and it is to acquaint those who
may be interested with some of the facts concerning this work that
this bulletin is issued.

It is desirable from our standpoint that plantings be made in regions
reasonably convenient to Boston so that at the proper season we may
have the privilege of examining the growing stock. They will, of course,
all represent unnamed seedlings, but it is expected that some of them
will present features of special horticultural interest and it may later be
desirable to perpetuate some of these by asexual propagation methods.

As a rule the breeding of new varieties of plants is done by artificial
cross pollination, but in the case of apples and cherries the plants are
largely self-sterile so that under proper conditions hybrids are produced
naturally. It has long been known that apples are partially or com¬
pletely self-sterile and must be cross pollinated to produce fruit and

[65]

set seeds. Trees of a clonal variety are inter-sterile so that in commer¬
cial orchards different varieties must be planted together to insure
proper pollination. The cross pollination is effected largely by bees,
and in many of the large western orchards hives of bees are distributed
through the orchards at blooming time. In New England the bumble
bees play an important part in orchard pollination.

The species of ornamental crabapples also are self-sterile and must
be cross pollinated in order to produce seeds. In the Arnold Arbore¬
tum these species and varieties are represented by single specimens
as a rule so that the seed produced by a single tree is the result of
pollination by the other trees in the vicinity. Consequently, the seed¬
lings produced by such a collection of species must be hybrids. There
is some limitation on crossing because the flowering periods of the
Asiatic and American species do not overlap and as a consequence
crossing is restricted to species within these two groups growing in
the Arnold Arboretum.

Seeds from species of crabapples were collected in the fall of 1938
and were planted in flats. Young plants were grown in the greenhouse
until they could be set out in the nursery plots in May. Most of these
seedlings are now from 2 to 4 feet tall and can be transplanted next
spring.

There are over 3,000 trees in the nursery representing the progeny
of 50 species and varieties. As expected most of the seedlings from
any species vary greatly in growth habit, leaf shape, and color, indi¬
cating that they are of hybrid origin. Some of the parental trees were
known to be of hybrid origin so that their progeny should vary even
if pollination were limited to a single male parent.

Among these crabapple species two produce only the parental types.
These species, Malus hupehensis (theifera) and M. toringoides, are
parthenogenetic and produce seed asexually without pollination. These
species fortunately are among the best of the flowering crabs, and can
be reproduced by seed regardless of their association with other spe¬
cies. A few of the other species show little segregation, but most of
them produce seedlings which are extremely variable.

Among the seedlings from the Arboretum collections there are many
dwarfs, a few prostrate or weeping types, and many variations in leaf
shapes and colors. Some have dark purple foliage all summer long
while others have color only in the fall. A few are very large and
vigorous and may have possibilities as root stocks for orchard trees.

It is hoped that many of the new combinations of species will pro¬
duce varieties of horticultural value. Types with attractive flowers,

[66]

Seedling Crabapples at the Arnold Arboretum After Their First Year of Growth.
These are the seedlings, 2 to 4 feet tall, which will be distributed in the spring of 1940

ornamental fruits and graceful growth habits will be selected as the
trees mature. The Arboretum now has several acres of nursery space
where many crabapple, lilacs, cherry, and rose seedlings will be grown
to the flowering stage.

There will be a considerable number of crabapple trees which we
cannot handle at the Arboretum and we hope that about 2,000 of these
seedlings can be placed on private grounds or estates. We plan to
distribute our surplus stock next spring to individuals who will care
for the young plants. If any particular orphan tree should prove to
be of exceptional value, the Arboretum reserves the right to obtain
propagating stock from it so that the variety can be more widely dis¬
tributed.

The surplus apple seedlings will be distributed in the spring of 1940.
Most of them should be of ornamental value and some should be new
and unusual types. Those interested in growing some of these hybrids
should send their request to Dr. Donald Wyman, at the Arboretum,
and indicate the number of seedlings desired. Because of the hybrid
nature of these seedlings, as explained above, the color of flowers and
fruit cannot be foretold. The plants will be delivered simply as crab¬
apple seedlings. However, since all have been grown from seed col¬
lected in the Arboretum where the best ornamental species are grown,
a large number should be of distinct ornamental value. It is under¬
stood that, in most cases, the prospective grower will obtain the young
trees at the Bussey Institution greenhouse at a time to be indicated
later, and see that the trees are properly planted and cared for.

George W. Skirm '

[07]

CONDITIONS UNDER WHICH CRABAPPLE SEEDLINGS

MAY BE OBTAINED

1. Each seedling must be carefully planted and given normal care
thereafter. They become the property of the person or institu¬
tion obtaining them.

2. Arboretum staff members will have the privilege of inspecting
these seedlings occasionally from time to time.

3. The Arboretum reserves the right to take propagating material
from any tree which proves to be of exceptional value.

4. The plants will be prepared for shipment by the Arboretum but
recipients are expected to make arrangements for their delivery
from the Bussey Institution greenhouse, South Street, Jamaica
Plain, at a time to be indicated later.

5. Because of the hybrid origin of these trees, color of flower,
fruit, etc., cannot be foretold; consequently they will be dis¬
tributed simply as unnamed seedlings, originating in the Arnold
Arboretum.

ARNOLD ARBORETUM

HARVARD UNIVERSITY

BULLETIN

OF POPULAR INFORMATION

Series 4. Vol. VII DECEMBER 15, 1939 Number 13

BOTANICAL EXPLORATION OF THE
MACKENZIE MOUNTAINS

BOTANICALLY unexplored mountain ranges are no longer com¬
mon in North America. A host of expeditions and local collec¬
tors, from the days of Kalm, Michaux, Douglas and Nuttall to re¬
cent times, have seen to that. The Mackenzie Mountains of north¬
western Canada have remained a challenge, not only to botanists but
to geographers and geologists as well, during the long period of more
active exploration around them. They are remote both by distance
and accessibility, hidden away in the vast wilderness of Yukon and
western Mackenzie, and drained only by broken, unnavigable streams.
A few hardy trappers and prospectors, and a few Indians who are
among the least civilized on the continent, are the only inhabitants.
But the development of air transport in recent years has altered all
our prospects for biological exploration. Even the most inaccessible
regions now become available for study by naturalists in various fields.

The Arnold Arboretum as part of its general program of field work
sponsored a collecting expedition to the Mackenzie Mountains during
the past summer. The main objectives were to make collections rep¬
resenting the flora of a part of this unknown region, and a study of
the local types of vegetation. The net results will be a contribution to
the broader problems of boreal phytogeography, for the summer’s work
will throw light on one of the largest blank spots in our plant maps
of the northern part of the continent. The field work was in charge
of the writer, who, with his wife, had been engaged in the botanical
investigation of the Mackenzie basin for several years ; and was financed
in part by grants from the Milton Fund of Harvard University, the
American Academy of Arts and Sciences, and the National Academy
of Science. The National Museum of Canada made generous loans of
field equipment. Mr. James H. Soper, of Hamilton, Ontario, served as
field assistant. Since it was especially desirable to reach the mountains
for spring collecting (mid-June), and since the Mackenzie system at
Great Slave Lake is not commonly open to navigation so early in the
season, plans for the whole trip had to be made a year ahead of time.

PLATE XI

Granite and shale mountains around the western end of Brintnell Lake. 1
expedition’s camp is on the shore near the right hand margin of the pictu

rimber line is from 1200 to 1400 feet above the level of the lake, and the effects
}f snow-slides may be seen in the spruce and birch forests on the steep slopes.

Most of the food supplies, collecting outfit, and heavier camping equip¬
ment were packed and shipped to the Hudson’s Bay Company at Fort
Simpson in the summer 1938. The party left Boston May 20, 1939,
and reached Simpson on June 8th, using a Mackenzie Air Service plane
for the last and ordinarily most time-consuming stage of the journey —
north from Fort Smith. A week at Simpson gave time to sort and re¬
pack supplies, and to collect the local spring flora along the Mackenzie
River.

On the 16th a chartered plane carried us to Brintnell Lake, a small
body of water at an altitude of 2600 feet in the Snyder Range, ap¬
proximately 200 miles west of Fort Simpson. This range lies in the heart
of the Mackenzie Mountain system, and is composed of rugged granite
and shale mountains, some of which reach elevations 9000 feet or more
above the sea.

It would be difficult to conceive of a more completely primeval
country than this. Two years ago a surveying party sponsored by Mr.
Harry Snyder of Montreal (for whom the mountains were named)
camped there for a few weeks ; and trappers spent a winter on the lake
a few years ago. Aside from these few visitors the lake and its sur¬
rounding mountains seem never to have been inhabited by human
beings. No evidence of Indian occupation could be found. Overland
travel proved extremely difficult due to the steep slopes and the com¬
plete absence of man-made trails.

The flora is a small one in number of species, and strongly Arctic
in character. Never-the-less a remarkably rich forest of spruce grows
op the lower slopes of the mountains. The timber line is from 1200 to
1400 feet above the lake, with colorful alpine meadow and crevice
vegetation above. The steeper slopes every where are made difficult for
plant growth by the prevalence of hazardous slide-roek; and on the
steep southward-facing surfaces the vegetation is subject to great dam¬
age by periodic spring snow-slides. Collecting and field studies of local
distribution problems engaged our attention until another plane came
for us on the 20th of August. A sectional canoe made possible short
trips about the lake, but otherwise we went on foot to the surrounding
country. No two mountain slopes had the same flora, so that the col¬
lecting did not become monotonous in spite of our confinement to one
region.

After a stay of three weeks in Fort Simpson we travelled southward
up the Mackenzie, Slave and Athabaska Rivers by slow stages, and
finally reached home on the 28th of September. The summer’s collect¬
ing netted some 15,000 herbarium specimens, over two thirds of which
are of flowering plants and ferns, and the remainder lichens, mosses
and fungi. Most of the material came from Brintnell Lake and Simp¬
son, although some very interesting plants, especially willows, were
gathered along the rivers as we travelled northward in the spring. The
collections will be studied at the Arboretum and the duplicates dis¬
tributed from it in exchange with herbaria throughout the world.

H UGH M. It AUP

[72]

INDEX TO SERIES 4

VOLUME VII

Synonyms are in italic; illustrations in bold face type.

Abeliophyllum distichum, Id
Acer rubrum, 16

— saccharinum, 16
Actinidia arguta, 33,34

— polygama, 34
Akebia lobata, 33

— pentaphylla, 33

— quinata, 33

— trifoliata, 33
Arborway, The, 24
Aristolochia durior, 33
Arnold Arboretum, Drought at

the, 41-42
— , Fires in the, 42
— , Hurricane damage at the,
1-4

— , When it was young, Plate
III, 22

Arnold Crab, 28

Bechtel’s Crab, (Malus ioensis

plena), Habit of, Plate V, 27
Benzoin aestivale, 16
Bloom, Order of, 53-64

— February, 55

— March, 55

— April, 55-56

— May, 56-61

— June, 61-63

— July, 64

— August, 64

— September, 64

— October, 64

Blooming dates for the Arnold
Arboretum, 1931-1939, 16
Breeding new varieties of crab-
apples, 65-68

Brintnell Lake, 72
Carmine Crab, 26
Celastrus articulata, 34

— flagellaris, 34

— orbiculata, 34

— scandens, 33-34
Cercidiphyllum japonicum, 16
Cornus mas, 16
Corylopsis, 13

— pauciflora, 1 6

Crabapple seedlings, Conditions
under which obtained, 68
Crabapples, Breeding new vari-
ties of, 65-68
Crabapples, Oriental, 26
Crabapples, The best flowering,
31

Daphne mezereum, 16
Dexter, Charles O., 11
Dirca palustris, 16
Drought at the Arboretum,
41-42

4 ‘Earl of Athlone”, 12
Eel Pond swamp, Woods Hole,
Plate VIII, 47

Emerson, George B. , Fellowship,
52

Exploration of the Mackenzie
Mountains, Botanical, 69
Fan Memorial Institute, 44
Fertilizers (for Rhodendrons), 12
Fires in the Arboretum, 42
Flowers, Malus, 31
Forsythia ovata, 13,16
Fruit, Malus, 31
Gold Medal of the Ministere

[73]

de l’Agriculture of the
French Republic, 14
Gore’s Meadow, 23
Great Slave Lake, 72
Hamamelis mollis, 16

— vernalis, 16
Hemlock Hill, 2
Hurricane, Age of trees

destroyed by, 3
— , Areas replanted after the,
2-4

— , Repairing damage done by,
1-4

Ihrig, Herbert, 5-12
Index Kewensis, Improved form
of, 37-40

, in its new Loose Leaf Form
at the Arnold Arboretum,

Plate VI, 39

— Supplement, 38
Japanese Black Pine (P.thun-

bergi), Plate IX, 49
Judd, William H., 16
Juniper rusts, 39
Kalmia latifolia, Blooming dates
in different regions, 53-54
Lawns, Salt water injury to,
45-46

Logs awaiting the saw mill at
Harvard Forest, Plate VII,

43

Lonicera praeflorens, 16
Loose-leaf binder, 40
Mackenzie Mountains, Botani¬
cal Exploration of, 69
Magnolia denudata, 16

— kobus borealis, 16

— soulangeana speciosa, 16

— stellata, 13,16

- - rosea, 13

Malus arnoldiana, 25

— atrosanguinea, 26

— baccata mandshurica, 25

— floribunda, 25
halliana parkmani, 25

. hupehensis, 25

— ioensis plena, 25

— ioensis plena (branch) Plate
IV, 23

— prunifolia rinki, 25

— purpurea, 26

— sargenti, 25,28
— , The best flowering crab-

apples, 31

— theifera, 25

— toringoides, 26,28
Meadow Road, 24
Menispermum canadense, 34

— dauricum, 34
Merrill, E.D., 14
Mountains around Brintnell

Lake, Plate XI, 70-71
North Meadow, The, 21-24
Order of Bloom of trees and
shrubs, 53-64
Periploca graeca, 34

— sepium, 34

Prinsepia sinensis, Seed source
of, 44

— uniflora, Seed source of, 44
Pruning of trees, 18
Prunus armeniaca 4 4 Mikado”

16

— concinna, 1 6

— davidiana, 16

— incisa, 16
— ■ mandshurica, 16

— nigra, 1 6
— ■ sargenti, 16

— subhirtella, 16

- - pendula, 1 6

— tomentosa, 16

[74]

Prunus triloba multiplex, 16
Pueraria thunbergiana, 34
Purple Flowered Crab, 26
Rhododendron Barbaturn, 7
— Barclayi “Helen Fox”, 6
californicum, 1 1
— Calophytum, 7
Calostrotum, 8
catawbiense, 10
ciliatum, 8

— culture, 11-12

— dauricum, 16
Davidsonianum, 7

— Dichroanthum, 10
eriocarpum, 8

— fastigiatum, 8

— fertilizers, 12

— Fortunei, 7
— ~ glaucum, 8

— heliolepis, 7

— hybrids, 10

— “Blue Tit”, 10

— “Betty Wormald”, 10
“Brittania”, 10
“Butterfly”, 10

— “Cornubia”, 10 .
“Corona”, 10

— “Dr. Stocker”, 10
“Glory of Littleworth”,

10

— ■ — “Goldsworth Yellow”,
10

- “King George”, 10

— impeditum, 8

— imperator, 8

— indieum, 8

— intricatum, 8
- — Irroratum, 7

— keleticuin, 8

— lutescens, 7

— macranthum, 8

macropbyllum, 11
malvaticum x Kaempferi, 8
maximum, 10
moupinense, 8
mueronulatum, 13

— myrtilloides, 8
pemakoense, 8
planting in the Northwest,
Plate I, 9

— racemosum, 8

— radicans, 8

— repens, 8
rubiginosum, 7

— russatum, 8

— scabrum, 8

— schlippenbachi, 16

— scintillans, 8

“ Tephropeplum, 8

— vaseyi, 16

— yunnanense, 7
Rhododendrons, “Garden

Merit” rating of, 7
Hardiness, rating of, 6
in the Pacific Northwest,
5-12

Salt water injury of woody .
plants, 45-51

Salt water injury, plants killed or
seriously injured by, 51
Salt water injury, Plants recov¬
ering from, 48

Salt water injury, Plants slightly
injured by 50-51
Salt water injury to lawns, 45-46
Seedling crabapples at the Ar¬
nold Arboretum, Plate X, 66
Sequence of bloom, 54
Shrubs, Order of bloom of,
53-64
Smilax, 34

[75]

Societe Nationale d’ Acclimation
de France, 14
South Street Hill, 2
Spring, This hesitant, 13
Street trees for New England,
17-20

Tea Crab, 25,26
Transplanting of trees, 17-18
Trees and shrubs, Order of
bloom of, 53-64

Trees and shrubs, Salt water in¬
jury to, 45-51

Trees destroyed by the hurri¬
cane at the Arnold Arbore¬
tum, 3

Trees for medium-width streets,
19

Trees for narrow streets, 19

Trees for ornamental planting
on the home grounds, 20
Trees of wide streets, 19
Twining vines, 33-36
Ulmus americana, 16
Viburnum fragrans, 13,14,16
Plate II, 15

Vines, Some twining, 33-36
Vines twining from left to right,

36

Vines twining from right to left,

36

Weld, Eleazer, 23
Wheeler, Wilfred, 45
Wisteria floribunda, 33, 35
— frutescens, 35
— - sinensis, 33, 35, 40
Yu Expedition, 44
Zumi Crab, 28

These Bulletins will be discontinued until spring of next year.

Subscription renewals for 1940 are now due. Send the subscrip¬
tion price of $1.00 to the Bulletin of Popular Information, Arnold
Arboretum, Jamaica Plain, Mass; at your early convenience.

[76]