Circular No. 2 
March, 1908
AL ABAMA
Agricultural Experiment 
Station
AUBURN
Cedar Apples and 
Apple Leaf-Rust
R. . SIONI,,
OpelikaI, Ala.
The~ Post Publhin~ g; Compny 
,
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CEDAR APPLES AND APPLE LEAF RUST.*
Among the various diseases of apples in Alabama the leaf-
rust, apple-rust or orchard-rust, is one of the most impor-
tant. The connection of this disease on the apple leaves
with the so-called "cedar apples" on species of cedar is
fully described in this circular. We desire to secure infor-
mation regarding the distribution of this apple leaf disease
in Alabama, the relative resistance of various sorts of ap-
ples to the disease and the date 
of the first appearance of
both the cedar apple on the cedars and the leaf rust on the
apple. We give below a description of the various sorts of
cedar apples thought to occur in Alabama, and hope those
to whom this circular is sent will co-operate in furnishing
data on the points mentioned above. A sheet bound at
the end of this circular can be torn off and returned to us
".ter being filled out.
LARGE CEDAR APPLES (Gymnosporangium macropus Link.)
The large cedar apple occurs on the twig and small leaf-
bearing branches of the red cedar (Sabina virginiana).
They ?ppear as globose or globular galls or swellings from
the size of a marble to a couple of inches in diameter. Dur-
ing the fall and winter the swellings have a reddish brown
color and harmonized well with a dark green of the tree.
Upon looking closely at the gall it will be seen to be cov.
ered with small circular pits, each of which has a raised
center. (See Figure 1). The gall feels somewhat spongy,
or lik- very hard rubber. In Spring during damp rainy
weather these galls send out numerous bright yellow spikes
of a jelly-like consistency. In this stage they are very no-
ticeable, and are sometimes referred to as "Cedar flowers."
*1 wish here to make my acknowledgements to Dr. E. Mead
Wilcox for his valuable suggestions and the photograph for figure
1; also to Dr. E. H. Jenkins, of the Connecticut Agricultural Ex-
periment Station for the use of the plate for figure 2, photo-
graphed by Clinton.
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time, about 58 days, these leaves show the yellow spots
which have just been described. The spores from the
Roestelia on the apple leaf blow back to the cedar and grow-
ing produce the cedar apple galls.
CEDAR APPLE (Gym-nosporangium flaviforme Atk.)
This cedar apple very closely resembles the large cedar
apple just described; in fact, it looks so much like it that
even with a microscope it can be separated from it only
with difficulty. It also grows on the red cedar. It pro
duces galls from a quarter of an inch to an inch in diame-
ter of a reddish brown color. The surface is marked with
shallow pit, having raised centers. In the .Spring after
warm rains the galls produce numerous spikes of a bright
yellow color and jelly-like consistency which here also con-
tain the spores. This cedar apple is especially numerous
where there are sugar-haw trees. (Crataegus spatula), grow-
ing, as it has its Roestelia stage on this tree or shrub.
This Roestelia (Roestelia flaviforme Atk.) has essentially
the same features as the (Roestelia pirita Thax.) on the
apple leaf. It occurs, however, on the sugar-haw (Crataegus
spatula).
SMALL CEDAR APPLE (Gymnosporangium globosum Farl.)
This also occurs on the red cedar, and is much like the
two preceeding species. However, it is usually smaller, hard,
woody, and often accompanied by an old, hard, dry swell-
ing of which the growing portion may form but half or a
third of the gall. In the Spring the living part of this gall
produces flat tongues of brownish color about one-fourth to
a half an inch long, and not nearly so conspicuous as the
large tedar apple. Where the large cedar apple with its
bright yellow spikes of jelly-like substance lasts but one
season this small cedar apple lasts a number of years.
The Roestelia stage of this cedar apple. occurs on many
varieties of the haw tree (Crataegus), also on the service
berry or June berry (Amelanchier alnifolia). This stage has
been known as Roestelia lacerata Am. Auct.
Gymnosporangium clavipes C. and P.
This occurs on the red cedar but does not produce a
large gall like those just described. It is small and incon-
spicuous and occurs on the small scaly branches under the
leaves forming a little brown cushion about the size of a
pin head. The small scale-like leaves on the affected
branches often become somewhat elongated and sharp point-
ed so they resemble the leaves of the common low juniper
(Juniperus communis). In the Spring these cushions are
orange colored and become a jelly-like mass about a quarter
of an inch long.
The Roestelia stage of this Gymnosporangium (Roestelia
aurantiaca Pk.) occurs on the leaves, stems, and young
fruit of the pear, quince and service berry or June berry
(Amelanchier.) The aecia are closely connected together and
appear a bright orange color from the spores within. The
peridium is erect or somewhat curved, about a quarter of
an inch long, whitish in color, shining and toothed at the
apex.
BIRD's NEST OR WVTCH's BROOM OF THE RED CEDAR.
(Gymnosporangium nidus-avis Thax.)
This also occurs on the red celar. When this fungus
attacks the red cedar an enormous number of short
branches are formed. They are bunched together and look
not unlike a small tree growing on the limb of the cedar
tree. This bush like growth is known as 
a witches' broom,
and from a distance somewhat resembles a large bird's
nest. Upon examining the affected branches the leaves are
found to be longer, sharper and stand out at a greater an-
gle than those on the healthy twig. The leaves closely re-
semble those of a low juniper in general appearance. At the
base of the leaves on the diseased twigs there may be found
small brownish gellatinous cushions containing the spores.
These appear in early spring.
The Roestelia stage of this fungus is formed on apple-
leaves and on the service berry or June berry (Amelan-
chier). This stage has been known as Roestelia nid u-avis
Than.
CLUB RUST OF THE JUNIPER (Gymnosporangium elavari-
forme (Jacq) Ress.)
This is found on the common low juniper (Juniperus
commnnnis) . The attacked branch swells up into a club
shaped or spindle shaped body often several inches long and
an inch or more in diameter. The gall is from necessity
very hard and woody. In early Spring small club-shaped
or cone-shaped masses of bright yellow jellatinous sub-
stance are sent out from the surface of this gall. These
masses make the gall more conspicuous and they contain
the spores of the fungus.
The Roestelia stage (Roestelia clavariforme Jacq.) is
found on the leaves of the apple and haw or thorn tree.
(Gymnosporangia in berrnudicnuntEarle.)
This occurs on the cedar (Sabina barbadensis) in the
counties very near the Gulf, especially near Mobile, and
farther south near Bayou Labatre.
The diseased spots are on the small branches carrying the
scale-like leaves. Very often the branches have somewhat
enlarged portions in which cup-shaped depressions. Early
in the Spring these enlarged portions give rise to the small
orange gellatinous spikes of material. Sometimes the end
of the affected twig dies and falls off.
This does not produce an apple leaf rust nor a leaf 
rust
on the haw or service berry. The Roestelia stage (Roeste-
hia berrnmudianuni, Farl) is formed on the same 
tree (Sabina
barbadtensis) and in the same enlargement 
that gives rise to
the winter-spore masses.
(Gymnosporangum biseptatum Ellis.)
This occurs on the white 
cedars (fCupressas thyoides 
)
on or tinder the leaves as small 
eruinpent velvety masses.
In damp weather in the Spring 
these become reddish brown
and gellatinous.
8
The Roestelia stage (Roestelia botryapites Schw.) occurs
on the leaves and fruit of the service berry or June berry
(Amelanchier canadensis or Amelanchier botryapis) as lit-
tie, reddish, brown, cylindrical tubes which are frayed out
at the ends.
The first five species described are definitely known to oc-
cur in Alabama, having been collected at Auburn. The last
three' species have not been collected, but since the hos:
plants are present it is not improbable that they also occur.
RELATIVE SUSCEPTIBILITY OF APPLES TO RUST.
In describing several of the cedar apple fungi we have
mentioned the apple as a host for 'the Rosetelia form, but not
all varieties of apples are equally susceptible to the disease.
The following varieties are usually free from rust, as shown
by our Experiment Station records:
Apple of Commerce,
Arkansas,
Black Buda,
Summer,
Black Ben Davis,
Champion,
Cooper's Early,
Epic,
Fanny,
Fall Pippin,
Garvenstein,
Hyari Piros,
Hershall Cox,
Henis Crab,
Jennings,
Kennard's Choice,;
Maggar,
Mitchel,
Mammoth Black Twig,
Maiden Blush,
Noble Savor,
Pasman,
Ponjik,
Red Astrechan,
Early Red Margaret,
Sabadka,
Summer Queen,
Saxon Priest,
Selymes,
Summer Cheese,
Shackleford,
Tuscaloosa,
Seedling,
Winesap,
Yakar,
Yates.
The following varieties are usually slightly affected:
Aikin, Keeskemet,
*Babbitt, M1avarack,
Buncomb, Oszi-voj,
Bledsoe, Pear.(Palmer),
Bradford, Red Limber Twig,
Bennony, ' Rowis Janeton,
Cillagoes, Red Beltigheimer,
Cannon, Sekula,
Pearmain, Summer Wafer,
Cooper's Red, Sweet Bough,
Dam, Thornton's Seedling,
Early Harvest, Taunton,
Elgin Pippin, Texas Red,
Grimes Golden, Yellow English,
Hands, Yellow Horse,
Homing, York Imperial.
Jefferies Ever Bearing,
The following varieties are badly affected:
Carolina Greening, Marvina,
Carters Blue, Nickajack,
Chattahoochee, Red June,
Equinettelee, Rome Beauty,
Family, Rodes Orange,
Hlaygood, Shockley,
Jonathan, 
Senator,'
Julian, Santa Mwalolybi,
Nioull fiers, Yopps Favorite.
Ma ngum,
MEANS OF PREVENTING APPLE RUST.
Spraying does not seem to be very successful. Some sta-
tions report some good results, others report no effect or
negative results. In our experiments here spraying did
not seem to check the disease.
The best plan is to plant those varieties that are not sus-
ceptibie to the disease. All cedar trees in the vicinity of
10
the orchard should be removed. These seem, at present, to
be the only means of controlling the apple leaf 
rust.
Since the cedar apple fungus has not been thoroughly
studied in Alabama, we are trying to gather as much ma-
terial as possible. It is not possible for us at this 
season
to visit all parts of the state. It would be a great help to
the Agricultural Experiment Station for any one seeing
any of the above described cedar apple fungi or Roestelia
to send them to Department of Botany, Auburn, Alabama.
In sending material the following directions should be
observed: If cedar apples are sent, cut off the branch a
little below the gall so that there will be four or five inches
of the branch with the leaves accompanying it. Also cut
off a small healthy branch and if possible include a few of
the little blue fruits. These should be packed with paper
in a pasteboard box. Place inside a slip of paper giving
your name and address and also the date on which the ma-
terial was gathered. If convenient, fill out the lower blank
in the last half of this circular and return it with the spec
imen.
If leaf rust of the apple, haw, or June berry, is sent do
as follows: Take a small twig with the diseased leaves 
or
fruit. Straighten out all the parts and press slightly be-
tween two pieces of blotting paper and allow to dry under
pressure for a day or two. If possible, a few flowers should
'be treated the same way and at lhe same time. If later in
the season a fruit or two will help to identify the haws
and service berries. These may be placed in a small box
or carefully wrapped in wrapping paper. Include a slip
giving name, address, 
-
and date on which material was col-
lected, or better still fill out and inclose the blank in the
upper half of the last page of this circular.
On the last page of this circular are printed two sets of
questions, one with reference to the cedar apple and one
with reference to the apple leaf rust. These are to be filled
out and sent in to us if possible. We would appreciate it
if you would fill out these blanks and return them to us
11
as soon as you have been able to make the observations.
These might be sent back inclosed with a sample 
of the ma-
terial.
Please address all information, inquiry, or material, 
to
DEPARTMENT OF BOTANY,
AUBURN,
ALABAMA.

APPLE-LEAF RUST OR ORCHARD RUST.
(Fill out this blank and return it as soon as the leaf-
rust appears .)
1. What varieties of apples are you growing?..........
2. Which varieties are most affected by leaf-rust ....
3. WVhich varieties are least affected by the leaf-rust?
4. At what date did the leaf-rust first appear this year?
5. What is the distance from your apples trees to the
nearest cedar trees ?...............................
6. Are these cedar trees affected with the cedar-apple dis-
ease?...................................
Name..........................
Post O'ce ... "f"... County....R. F. D. No...
CED)AR APPLES.
(Pill out this blank and return it as soon as the gela-
tinous spines appear on the cedar apples.)
1. At what date did the gelatinous spines first appear?
2. Do you find more than one sort of cedar-apple? ...... .
3. Are these cedar trees near apple, wild crab, quince, pear,
haw or -service berry trees?.......... f.... .
Name...... ..f "" . .. .f. . .. .. .". . ...
Post Office ... ".......County ......R. F. D. No...