SD

"Bluing" and the "Red Rot"
of the Western Yellow Pine,
withSpecial Reference to the
Black Hills Forest Reserve

Plant Industry, Bull. 36

IRLF

U. S. DEPARTMENT OF AGRICULTURE.
BUREAU OF PLANT INDUSTRY— BULLETIN NO. 36.

B. T. GALLOWAY, Chief of Bureau.

THE "BLUING" AND THE "RED ROT" OF THE WESTERN

YELLOW PINE, WITH SPECIAL REFERENCE TO

THE BLACK HILLS FOREST RESERVE.

HERMANN VON SCHRENK,

SPECIAL AGENT IN CHARGE OF THE MISSISSIPPI VALLEY
LABORATORY,

VEGETABLE PATHOLOGICAL AND PHYSIOLOGICAL INVESTIGATIONS.

ISSUED MAY 5, 1903.

WASHINGTON:

GOVERNMENT PRINTING OFFICE.

1903.

BUREAU OF FLAM INDUSTRY.

B. T. GALLOWAY. (Mef.
YKGKTAKLK PATHOLOGICAL AND . PI I YSK >L< M ; K 'AL 1NVKSTH i A TI< >XS.

Al.llERT I''. AVoODS. ratlioloifiC anil I'hi/xiolot/iC.

KRWIX F. SMITH, I'atholoijiC in < '/mr</>> <>f Laltoratorij <>j ' /'/(nit Pathology.

GEOK<;K T. ^fooKE, Physioloyixt in. Ch<ii-(/<' of L>tl>or<if<>,4!/ of I'l/int Physiology.

HERBERT J. WEBBER, Physiologist in (.'limye of Laboratory of Plant Hivediinj'.

XEWTOX B. PIERCE, Pathologist -in Charge of Pacific Coast Laborator;/.

HERMANN vox SCIIRENK, Special A </<nt in Ch&rgeofMiwissijppi V<ill<:ii J,«l»n-<tt<n-/i.

P. H. ROLFS, Pathologist in Charge of $ub- Tropical Laboratory.

M. li. AVAITE, Pathologist in ('h<ir</>' of Imrxt'ignl'inn* of Dixetixrx of <_>,•<•!,</,•</ Fruit*.

MARK A. TAKLETOX, Cerealist.

WALTER T. SWINGLE, Phii*iolngixt in. Ch&rge of L[f< .HiCn,-;i Znw&gajkivns.

('. < ). TOWXSEXD, Pallioloyixi.

P. H. DORSETT, Pathologic.

T. H. KEARNEY, PJiysiolof/i*t, Plant Hfi'i'dimj.

CORXELH'S L. SlIEAR, AxxiCant I'nfJiolotjiC.

WILLIAM A. ORTON, .Axxidint I'atlio/ogixf.

FLORA W. PATTERSON', MycologiC.

JOSEPH S. CHAMBERLAIN, Expert in. Physiofoaical Clu-iiiiCr;/.

K. I-!. I'.. McKi-NXKY. Expert.

CHARLES P. HARTLEY, Assistant in Physiologi/, riant Breeding.

I)EANE B. SWINGLE, A**iCant in Patliology.

JAMES B. RORER, A*xi4ant '.in Pathology. ,

LLOYD S. TEXXY, Assistant in Pathology.

JESSE B. NORTON, Assistant in Physiology, Plant

A. \\r. IU)HON, Scientific Assistant, Plant Breeding.

KARL F. KELLERMAX. A^ic.unt in Physiology.

( ;I:OI;I-K ( i. HEDGCOCK, Assistant in Patholog;/.

Bui. 36, Bureau of Plant Industry. U. S. Dept. of Agriculture .

Plate I.

CROSS SECTION OFA DYINGTREE OFTHE BULL PINE, SHOWING BLUE COLOR.

U. S. DEPARTMENT OF AGRICULTURE.

BUREAU OF PLANT INDUSTRY— BULLETIN NO. 36.

B. T. GALLOWAY, Chief of Bureau.

THE "BLUING" AND THE "RED ROT" OF THE WESTERN

YELLOW PINE, WITH SPECIAL REFERENCE TO

THE BLACK HILLS FOREST RESERVE.

BY

HERMANN VON SCHRENK,
'/

SPECIAL AGENT IN CHABGE OF THE MISSISSIPPI VALLEY
LABORATORY,

VEGETABLE PATHOLOGICAL AND PHYSIOLOGICAL INVESTIGATIONS.

ISSUED MAY 5, 1903.

WASHINGTON:

GOVERNMENT PRINTING OFFICE.

1903.

<\

\

LETTER OF TRANSMITTAL

U. S. DEPARTMENT OF AGRICULTURE,

BUREAU OF PLANT INDUSTRY,

OFFICE OF THE CHIEF,
Washington, D. C., December %h 1902.

SIR: I have the honor to transmit herewith a technical paper on
The " Bluing" and the "Red Rot" of the Western Yellow Pine, with
Special Reference to the Black Hills Forest Reserve, and respectfully
recommend that it be published as Bulletin No. 36 of the series of this
Bureau.

This paper was prepared by Dr. Hermann von Schrenk, Special
Agent of this Bureau in Charge of Timber Rot Investigations, a line
of work being conducted jointly by this Bureau and the Bureau of
Forestry, and it was submitted by the Pathologist and Physiologist
with a view to publication.

The illustrations, which comprise 14 full-page plates, several of
which are colored, are considered necessary to a full understanding of
the text.

Respectfully,

B. T. GALLOWAY,

Chief of Bureau.
Hon. JAMES WILSON,

Secretary of Agriculture.

PREFACE.

The report submitted herewith, entitled The " Bluing" and the
"Red Rot" of the Western Yellow Pine, with Special Reference to the
Black Hills Forest Reserve, covers in part an investigation under-
taken by the Bureau of Plant Industry in cooperation with the Bureau
of Forestry in the broad field of the diseases of forest trees and the
means of controlling them, as well as the causes of and methods of
preventing the decay of all kinds of timber, especially that valuable
for construction purposes. At the present time an immense quantity
of dead and dying timber of the bull pine is standing in the Black
Hills Forest Reserve, South Dakota. The amount has been variously
estimated, but will probably approach 600,000,000 feet. The death of
the trees was caused by the pine-destroying beetle of the Black Hills,
as shown by investigations conducted by the Division of Entomology
of the United States Department of Agriculture. a Following attack
by the beetles the wood of the tree is invaded by various fungi, one of
which causes the blue coloration of the wood. Dr. von Schrenk has
demonstrated, however, that the fungus which causes the bluing does
not injure the strength of the wood.

The rapid decay or "red rot" of the timber is caused by another
fungus, and its ravages can be forestalled by a proper use of the
wood. A series of recommendations is made, which, if followed, will
result in the saving of a very large part of the dead wood.

ALBERT F. WOODS,
Pathologist and Physiologist.

OFFICE OF THE PATHOLOGIST AND PHYSIOLOGIST,

Washington, D. C., December <23 , 190%.

«Bull. 32, n. s., Division of Entomology, U. S. Dept. of Agriculture, 1902.

5

CONTENTS,

Page.

Introduction 9

Death of the trees 9

When are the trees dead 11

The ''blue" wood 11

Rate of growth of the blue color 11

Nature of the "blue" wood 12

Strength of the "blue " timber 13

Lasting power of the "blue" wood 14

The "blue" fungus 15

Effect of ' ' blue ' ' fungus on the toughness of the ' ' blue ' ' wood 20

Relation of the ' ' blue " fungus infection to the beetle holes 20

Fruiting organs of the "blue" fungus 22

Growth in artificial media 23

Dissemination of the spores 24

The blue color 24

Summary 26

Decay of the "blue" wood 26

The "red rot" of the western yellow pine 27

Cause of the "red rot" 27

Conditions favoring the development of the ' ' red-rot ' ' fungus 28

Final stages and fruiting organs 28

Rate of growth of "red rot " 30

Amount of diseased timber 31

Possible disposal of the dead wood 32

In the Black Hills 32

In the remaining parts of South Dakota 33

Value of the dead wood 33

Inspection 33

Recommendations 34

Description of plates 38

7

ILLUSTRATIONS.

Page.
PLATE I. Cross section of the trunk of a dying tree of the western yellow or

bull pine, showing blue color Frontispiece.

]I. Dying trees of the bull pine. Fig. 1. — Green, "sorrel-top," and

' ' red-top ' ' trees. Fig. 2. —Green and ' ' sorrel-top ' ' trees 40

III. Color change in leaves of the bull pine. 1. Leaves from healthy

tree. 2. Leaves from "sorrel-top" tree. 3 and 4. Leaves from
trees turning to the "red-top" stage 40

IV. Fig. 1. — "Red-top" tree in a group of healthy trees near Elmore,

S.Dak. Fig. 2.— "Black-top" trees 40

V. Figs. 1 and 2. — Sections of trunks of the bull pine, showing early

stages of "blue disease " 40

VI. "Blue" sections from dead trees. Fig. 1. — Sections from tree dead

five months. Fig. 2. — Sections from tree dead eighteen months . . 40
VII. Mycelium and fruiting bodies of the "blue" and "red-rot" fungi.
1. Tangential section of "blue ' ' wood. 2. Cross section of ' ' blue' '
wood. 3. Cross section of a medullary ray. 4. Young perithecium
of the ' ' blue ' ' fungus. 5. Mature perithecia of the " blue " fungus.
6. Two perithecia of the "blue" fungus. 7. Two asci with spores
of the "blue" fungus. 8. Spores of the "blue" fungus. 9. Top
of beak of perithecium of Ceratostomella pilifera just after the dis-
charge of the spore mass. 10 and 11. Median sections of sporo-

phores of the ' ' red-rot ' ' fungus 40

VIII. Sections of "blue" wood. Fig. 1.— Radial section. Fig. 2.— Tan-
gential section

IX. Pieces of wood from the bull pine, showing blue fungus starting

from holes made by a wood-boring beetle 40

X. Sections showing early stages of the "red rot." Fig. 1. — Section
taken 35 feet from the ground from a dead tree. Fig. 2. — Section
showing more advanced stage of decay. Fig. 3. — Section from tree

shown in fig. 2, made 15 feet higher up 40

XI. Sections from "black-top" bull pines, showing advanced stages of
decay. Figs. 1 and 2. — Sections from the top of a fallen tree. Fig.

3. — Section from a standing pine 4 feet from the ground 40

XII. Group of broken " black-top" trees 40

XIII. Fig. 1.— Top of "black top" broken off. Fig. 2,—Polyporus pon-

derosus growing on dead pine stump 40

XIV. Sections of rejected cross-ties. Fig. 1. — Wood affected with "red

rot." Fig. 2. — Diseased wood from living tree 40

8

B. P. I.— 46. V. P. P. I.— 100.

mHE " BLUING" AND THE "RED ROT" OF THE WEST-
ERN YELLOW PINE, WITH SPECIAL REFERENCE TO
THE BLACK HILLS FOREST RESERVE.

INTRODUCTION.

The present investigation was undertaken to determine —

(1) The cause of the blue color of the dead wood of the western
yellow pine, commonly known as the bull pine (Pinus ponderosd), and
the effect of the coloring on the value of the wood.

(2) The reason for the subsequent decay of the wood, the rate of
decay, and whether the decay could be prevented.

(3) Whether it would be possible to use the dead wood before it
decayed; first, to reduce the fire danger; second, to prevent the decay
and thereby save an immense quantity of timber.

DEATH OF THE TREES.

The physiological changes which take place in the bull pine (Pinus
ponderosa) as a result of the attack of the pine-bark beetle (Dendroc-
tonus ponderosse Hopk/') are intimately connected with the fungus
diseases under consideration, and may therefore be referred to briefty.

According to Hopkins, the beetles enter the bark of the living trees
in July, August, and September. The primary longitudinal burrows or
galleries are excavated by the adult beetles, and the transverse, broad,
or larval mines (Bull. 32, n. s., Division of Entomology, U. S. Depart-
ment of Agriculture, Pis. I and III and fig. 1) through the inner bark
and cambium of the main trunk have the effect of completely girdling
the tree, and by September the cambium and the bark on the lower
portion of the trunk are dead. The foliage of the trees thus attacked,
however, shows no change from the normal healthy green until the
following spring, when the leaves begin to fade.

The first signs of disease noticeable in an affected tree are visible in
the spring of the year following that of the attack by the beetle. Here

a Hopkins, A. D. Insect Enemies of the Pine in the Black Hills Forest Reserve.
Bull. 32, n. s., Division of Entomology, U. S. Dept. of Agriculture, pp. 9, 10.

9

10 THE "BLUING" AND THE "RED ROT" OF THE PINE.

and there one will find the needles of affected trees turning yellowish.
The bright green fades almost imperceptibly, starting near the tip of
the needle. The needles first affected are those on the lowest branches
(PL II), and on these branches the discolored leaves will be more or
less scattered. By the end of May most of the leaves on an affected
tree will be pale green or yellowish. (PL II; PL III, 2.) This yellow
color increases in intensit}T during the summer and makes the affected
trees a conspicuous mark among the healthy green trees. Trees in this
stage are locally known as "sorrel tops" or "yellow tops." When
standing on a hillside, groups of "sorrel tops" can be easily detected at
a distance of several miles. It is rather a difficult matter to show the
contrast in a photograph. The middle tree on PL II, fig. 1, shows the
contrast with the green trees on the left to some extent.

The yellow needles are drier than the green ones and show a marked
disintegration of the chlorophyll. As they continue to diy the color
changes gradually through various intermediate stages (PL III, 3) to
a reddish brown. This color (PL III, 4) becomes very marked after
the trees have passed through the second winter. The needles are
then dry and they begin to fall off. Such trees are known as "red
tops." (See PL II, fig. 1; PL IV, fig. 1.) The leaves finally fall off
completely, leaving the branches bare. Such trees without any leaves
are known as "black tops." (PL IV, fig. 2.) The group of trees on
PL II, fig. 1, shows the green trees and the "sorrel tops" and "red
tops" (rapidly becoming "black") side by side.

To summarize the foregoing: One finds the living trees attacked in
July and August; the following spring the leaves turn }^ellow ("sorrel
tops") and gradually red ("red tops"), and the third year they drop
off altogether ("black tops"). It is a difficult matter to say at what
point the trees are dead. Girdled trees die with different degrees of
rapidity, depending upon the species. The black gum (Nyssa sylvatica)
will live — i. e., will have green leaves — for two years after being gir-
dled; so also several species of oak. Pines and spruces rarely live
more than a year, and generally not so long.

The reason for the different behavior of these trees is probably to
be found in the different power to conduct water through the inner
sapwood. The subject is one about which little is known as yet. In
the case of the bull pine, after the girdling by the beetles certain
changes take place in the cambium and the newer sapwood which
leave no doubt as to the death of those parts. By September, as
described below, the cambium and bark are actually dead and par-
tially decayed for 30 feet or more from the ground. The leaves are
still green and full of water the following spring. The only way in
which this can be accounted for is by assuming that sufficient water
passes through the inner sapwood to keep the crown of the tree
supplied

THE "BLUE" WOOD. 11

WHEN ARE THE TREES DEAD?

The question as to when a tree is dead is one of considerable prac-
tical importance in determining which trees in the forest should be
cut. For this purpose it is safe to assume that a tree may be pro-
nounced dead when the bark is loose at the base of the tree for con-
siderable distances up the trunk. A tree with its bark in this condi-
tion can not possibly recover. The wood under this loose bark will
always be found to be dark in color and will appear covered with
shreds of bark when the bark is pulled off. It must be remembered
that such trees will have green leaves. The criterion of green or yel-
low leaves is not a safe one to follow, and ought not to be considered
in making specifications for cutting dead timber. Attention is here
called to the recommendation (4) made on page 35.

THE "BLUE" WOOD.

Very soor. after the attack of the bark beetles (Dendroctonus pond-
erosde) the wood of the pine turns blue. The color at first is very
faint, but it soon becomes deeper. A cross section of a trunk several
months after the beetle attack will appear much as shown on PL V,
fig. 1. Lines of color extend in from the bark toward the center of
the tree, and increase rapidly- in intensity until the colored areas stand
in sharp contrast to the unaffected parts. The color appears in small
patches at one or more points on the circumference of the wood ring.
At first it is a mere speck, but this gradually spreads laterally and
inward, eventually forming triangular patches on cross section. The
color likewise spreads up and down the trunk from the central spot.
As the time passes after the first attack of the beetles, several color
patches may fuse. Their progress laterally and upward toward the cen-
ter of the trunk may be equally rapid on all sides of the tree, or more
rapid on one side than on another (PL V, fig. 2). The intensity of the
color may vary considerably on the two sides of one and the same trunk.
After a certain period of time the whole sapwood will have a beautiful
light blue-gray color, as shown on PL I. The wood which adjoins the
inner line of the "blue" wood is of a brilliant yellow color, which con-
trasts sharply with the blue outside and the straw yellow of the heart-
wood. This yellow area is in the form of a ring of more or less irregular
shape. Sometimes it is formed of one annual ring very sharply
defined; then, again, it may include all or only parts of several annual
rings. As the wood grows older, the blue color becomes deeper and
the yellow ring more sharply defined.

RATE OF GROWTH OF THE BLUE COLOR.

The first signs of the blue color are usually found several weeks after
the attack by the beetles at points on the trunk in the immediate

" " "

12 THE " BLUING" AND THE "RED ROT OF THE PINE.

vicinity of the attack. The first signs of the blue color are found in
the base of the trunk. On PL VI, fig. 1, three sections of a tree which
was attacked the latter part of July, 1901, are shown. The sections
were cut in November, 1901, at points 5 feet, 16 feet, and 36 feet from
the ground. The sapwood of the first section, 5 feet up, is entirely
blued; the second section, 16 feet up, is blue here and there; while the
section made in the top, 36 feet up, is without a particle of blue color.
Note in this connection that the sections with blue color show the cross
sections of the galleries of the bark beetles {Dendroctonus ponderosse) in
the layer formed by the cambium layer, the outer wood, and the inner
bark. The sections on PL VI, fig. 1, show some of these galleries filled
with sawdust. A more advanced stage is shown on PL VI, fig. 2. In
this tree the sapwood is blue from the ground up into the extreme top.
The smallest section, cut from the tree in the upper part of the crown,
is blue with the exception of the innermost rings, i. e., the beginning
of the heartwood.

The blue color develops very rapidly when once the tree is attacked.
Standing trees attacked by the beetles in July, 1902, showed signs
of blue color in three weeks. Three months after the attack the
sapwood of the lower part of the trunk is usually entirely blue, as
shown on PL I. The year following the attack, i. e., when the trees
have reached the "sorrel-top" stage, the bluing has reached the top,
and late that year, when the "red-top" stage is reached, the entire
sapwood is blue (PL VI, fig. 2).

An experiment was made during the past summer to see whether
the blue color would appear in trees felled before being attacked by the
pine-bark beetle. It may be said at this point that they did "blue"
just as the standing ones did.

NATURE OF THE " BLUE " WOOD.

Some weeks after the attack by the bark beetles, changes take place
in the bark and the newer wood which ultimately result in the bark
becoming loose and separating -from the tree. When the first flow of
resin into the galleries has stopped, the air enters into the galleries, and
channels of communication with the outside are established through
which the water in the cambium and newer wood can escape. The
result of this is that a moist atmosphere prevails in the air chambers,
very favorable to the growth of fungi. As the cambium and bark
cells lose water they shrivel and break from one another, so that after
a few months the bark breaks away from the wood proper. On the
south and southwest sides of the trees the bark dies most rapidly, and
here, contrary to the general occurrence, it frequently adheres firmly
to the tree. On the shaded sides of the trunk the bark becomes
loosened, as described, before six months have elapsed. The surface
of the wood is moist, very dark in color, and feels somewhat clammy.

THE "BLUE" WOOD. 13

Numerous white strands of fungus mycelium make their appearance
after six months or more. As the wood of the trunk dries, the bark,
loose at first, tightens, so that in the " black-top" stage it adheres
quite firmly to the trunk. When cut into, it peels off in large sheets
very readily, however.

The " blue " wood differs very little from the sound wood in general
appearance, except its color. It is full of moisture at first, but loses
this rapidly, so that in two years after the beetle attacks the wood
it may be almost perfectly seasoned, even when completely covered
with its bark. The ' 4 blue " wood is said to be very much tougher
than the green wood, so much so that the tie makers in the Black
Hills can be induced to cut wholly blued wood only with difficulty.
This toughness and a possible reason therefor are discussed hereafter.

STRENGTH OF THE "BLUE" TIMBER.

Ever since its first appearance there has been considerable discussion
as to the strength and durability of the "blue" timber when com-
pared with sound timber. It was universally believed that it would
prove very much inferior in both respects. A test was made in the
testing laboratory of the department of civil engineering of Washing-
ton University, St. Louis,05 to determine the comparative strength of
the "blue" and the healthy timber. Sections of tree trunks 5 feet
long were cut from trees at points 10 to 15 feet from the ground, and
were shipped to St. Louis, where they were sawed into blocks of sev-
eral sizes. For the compression tests, blocks 2 by 2 by 4 inches and
3 by 3 by 6 inches were cut and planed to the exact dimensions, or as
nearly so as possible.

For the cross-breaking strength, sticks 2 by 2 inches by 4 feet, and
3 by 3 inches by 4 feet were prepared. The blocks for these tests were
kiln-dried at a temperature of 172° F. until an approximately constant
weight was reached. It was found that completely dried blocks would
not shear at all. The moisture content of the green blocks was slightly
higher than that of the "blue" blocks.

Three kinds of timber were used: A — Green timber; B — "Blue" tim-
ber taken from "sorrel-top" trees, i. e., trees dead about one year;
C — "Blue" timber taken from "red tops" and "black tops" (mostly
the latter), i. e., trees dead about two years.

The tests were made with the machinery described by Johnson
in early reports6 of the Division of Forestry. Every block was
carefully measured. The results, reduced to the average crushing
strength and the average cross-breaking strength per square inch, are

« The machinery was put at the writer's disposal through the courtesy of Prof. J. L.
Van Ornum.

& Timber Physics, Bulls. Nos. 6 and 8, Division of Forestry, U. S. Department of
Agriculture.

14 THE ''BLUING" AND THE "RED ROT" OF THE PINE.

given in the following table. The number of pieces used for each
test is given in a separate column. It will be noted that the heart-
wood pieces were kept distinct from the pieces cut from the sapwood.

Compression strength in pounds per square inch.

Kind of timber.

Heart wood.

Sapwood.

Number
of pieces
tested.

Average
strength.

Number
of pieces
tested.

Average
strength.

A. Green timber

210
190
131

Pounds.
3,919.74
3, 876. 44
4,017.48

1,675
649
770

Pounds.
5, 089. 98
5, 130. 95
5, 308. 32

B. " Blue " timber, 1 year old ,

C. " Blue " timber, 2 years old

Cross-breaking strength in pounds per square inch.

Kind of timber

Heartwood.

Sapwood.

Number
of pieces
tested.

Average
strength.

Number
of pieces
tested.

Average
strength.

A. Green timber

338
317
322

Pounds.
5,375.26
5, 361. 17
5,666

553
242
272

Pounds.
5, 832. 66
5,818.84
6, 843. 31

B. "Blue" timber, 1 vear old

C. " Blue" timber, 2 years old

The figures given in this table show that the "blue" timber is
slightly stronger, both when compressed endwise and when broken
crosswise. This result is probably due to the fact that the "blue"
wood was slightly drier than the green wood when the tests were
made. It is scarcely probable that the presence of fungus threads in
the cells of the wood in any way strengthens the fiber. However
that may be, these tests show beyond doubt that for all practical pur-
poses the " blue " wood is as strong as the green wood. Under the con-
ditions now existing in the Black Hills Forest, the "blue" wood is cer-
tainly very much stronger than the green wood. It is in effect sea-
soned timber. The trees have stood in the most favorable position
possible for drying, with thousands of holes in the bark made by the
beetles through which the water could escape, assisted by the winds
which constantly sweep by the trunks. Where wood is used, as it
unfortunately is in these days, almost immediately after it is cut from
the forest, the "blue" wood is certainly as good so far as its strength
is concerned as the green wood, and ought not to be discriminated
against because of supposed weakness.

LASTING POWER OF THE "BLUE" WOOD.

The wood of the bull pine is one which is not very resistant to
decay-producing fungi. Under ordinary conditions, such as are found

THE "BLUE" FUNGUS. . 15

in the State of Nebraska outside of the arid belts and in the Black
Hills, the wood will last from four to six years when placed in the
ground in the form of a cross-tie, for instance. Dead trees may stand
in the forest for many years without decaying, especially when killed
by fire, but ordinarily when the bark remains on the trees they begin
to decay after the third year.

From observations made on the "black-top" trees now standing in
the forest it would seem that the lasting power of the "blue" wood
would be very small. It is perhaps not fair to compare these trees
with sound ones, for their bark is full of holes, giving fungus spores
every opportunity to enter, as described below. When placed in the
ground this wood rots very fast, if one can draw conclusions from the
dead tops lying around in the forest. There is every reason why it
should rot rapidly. The hyphge of the "blue" fungus have opened pas-
sageways for the rapid entrance of water and for other fungi in almost
every medullary ray. Dried wood will probably last a long while,
especially if properly piled, so as to allow the air to circulate between
the separate pieces. When sawed and split for cord-wood, the "blue"
wood should keep just as long as the green wood. The tendency to rapid
decay can be largely done away with by treating the wood with some
preservative. Ties were cut during the past spring from green timber
and from dead trees. These were shipped to Somerville, Tex., where
they were impregnated with zinc chloride. These ties were laid in
the tracks of the Santa Fe Railroad and are now under observation.
A second lot of ties has been cut during the past summer from green
trees and from "sorrel tops," "red tops," and "black tops." These
will be treated within a short time and laid in the track of a Mexican
railway so as to determine the relative resistance of the various grades
of "blue" timber in a tropical climate as compared with the green tim-
ber. On the particular road chosen for this experiment the life of very
resistant timbers is short.

THE "BLUE" FUNGUS.

The blue color of the wood is due to the growth of a fungus in
the wood cells. The staining of wood due to fungi has been known
for many years, especially the form known as 4 ' green wood " (bois
verdi). In Europe this green coloration attracted the attention of
foresters and investigators as early as the middle of the last century,
and a number of descriptions and discussions appeared from time to
time (particularly in France), in which an attempt was made to account
for this phenomenon. A green dye was extracted from this wood,
which at one time was thought to be valuable because of its absolute
permanency. Various dicotyledonous woods showed the green color;
among others, beech, oak, and horse-chestnut.

16 THE "BLUING" AND THE "RED ROT" OF THE PINE.

In spite of numerous investigations, the causes of the green color
and its relation to the wood remained comparatively obscure until
recently, when Vuillemin published an extended account a showing
that one form of the green color was due to the growth in the wood
of one of the Discomycetes, Helotium deruginoswn. Vuillemin men-
tions a number of other fungi which have been described as causing
the green color, among others, Propolidium atrocyaneum Rehm, on
wood of the poplar; JVsevia seruginosa Rehm, on the tansy; and
Fusarium a&ruginosum Delacroix, on potato tubers.

Without going into details, Vuillemin established the fact that the
green coloring matter, called X37lindeine, is formed by the hyphse of
Helotium xruginosum, and that the presence of these green-colored
hyphse gives the green color to the wood. The wood fiber itself
remains colorless. The xylindeine is soluble in alkalis and can readily
be extracted. The wood fiber is not destroyed, but remains intact.
The name "green decay" is therefore incorrectly applied, for the
green wood is in no sense decayed. This is an interesting fact, for it
will be remembered that the same has been said of the "blue" wood.
A more detailed comparison of the relation of this green coloring mat-
ter and the fungus forming it to the coloring matter in the "blue"
wood will be published in another paper.

The blue stain of coniferous woods is a familiar defect in the United
States, particularly in the South, where freshly sawed lumber,
especially shingles and lath, is affected during the moist warm weather
of April, May, and June. The blued lumber is considered as a low-
grade material, and many precautions are taken by Southern manufac-
turers to prevent loss. A full account of this trouble and a discussion
as to its cause and methods for its prevention are now in preparation.

In Europe the blue color of pine wood was first noted by Hartig,6
who refers briefly to the fact that a fungus ( Ceratostoma piliferum
(Fr.) Fuckel), is the cause of bluing in coniferous wood, especially of
pine trees which have been weakened by caterpillars, and of firewood.
He states that the hyphae of this fungus, which are brown, grow rap-
idly inward into the trunk through the medullary rays and that they
avoid the heartwood, probably because of its small water content.

The blue color of coniferous wood in this country is probably caused
by the same fungus referred to by Hartig, although it seems necessary
to refer to it under a different name (Ceratostomella pilifera (Fr.)
Winter).

« Vuillemin, Paul. Le Bois Verdi. ( Bull, de la Soc. d. Sciences de Nancy, Ser. II,
15: 90-145; 1898. 1 pi.) References to earlier works on the green color are given
in this paper.

& Hartig, Robert. Lehrbuch der Pflanzenkrankheiten, 1900, pp. 75 and 106. (See
also earlier editions of the Lehrbuch fur Baumkrankheiten; see also Frank, A. B.,
Krankheiten der Pflanzen, 1: 107, 1895.)

THE "BLUE" FUNGUS. 17

CERATOSTOMELLA PILIFERA (Fr. ) Winter.

Splitvria pilifera Fr. Systema Mye., 2: 472, 1830; Berkeley, Grevillea, 4:

146, 1876.

Sphferia rostrata Schum. Enum. Fl. Sae., 2: 128.
Ceratostoma piliferum (Fr. ) Fuckel. Symb. Myc., p. 128; Ellis & Everhart,

N. A. Pyrenomycetes, p. 193.
Ceratostomella pilifera (Fr. ) Winter. Rabenhorst's Kryptoganienflora, etc.,

1, Pt. II: 252, 1887; Engler & Prantl, Nat. Pflanzenfam. , Pt. I, Abt. 1 : 406;

fig. 259.

The ''blue" fungus was first described by Fries, who placed it in the
genus Sphderia. Later it was placed in a new genus (Ceratostoma} by
Fuckel, and remained in this genus until recently, when Winter in
his revision of the family Ceratostomese put the fungus in the genus
Ceratostomella.a This genus is characterized as "perithecia more or
less superficial, or immersed (sometimes only for a short time), gener-
ally tough, leather}7-, or carbonaceous, with marked, generally well-
developed beak. Spores variable, typically unicellular, hyaline.
Species mostly on wood." The genus Ceratostoma differs from Cera-
tostomella only in having the spores brown instead of hyaline. This
seems a very weak character upon which to separate two genera, and
Winter realizes this, as indicated in a note (p. 253), where he says: "I
hesitate to accept the genus Ceratostomella, for the different color of
the spores does not seem to be sufficient basis for a genus. I do it
only to satisfy generally accepted demands."

As the present investigation is not materially concerned in the valid-
ity of any particular name, the writer accepts Winter's name, leaving
the question of whether it ought to be Ceratostoma or Ceratostomella
to others.

Ceratostomella pilifera occurs, according to Winter, on coniferous
woods, mostly on pine timber. Winter remarks that in spite of the
very common occurrence of this species, he was able to find the mature
asci but once, and gives a figure of the two asei he saw. This is borne
out by the findings mentioned hereafter. Four forms of C. pilifera
are described, which are probably forms modified by the substratum
on which they grew, and of less interest in this connection.

The fruiting bodies of the "blue " fungus occur in thousands on blued
logs and boards in favorable seasons; the long necks of the perithecia
when looked at sideways form veritable forests on a board. In the
pine forests of the Black Hills the perithecia are to be found on decay-
ing sticks, in the cracks formed when trees or branches break off, and
sometimes under the loosened bark of dead trees. It is a strange fact,
however, for which no very plausible reason can as yet be assigned,
that with the thousands of dead and "blue" trees now in that forest
the asci of the fungus should be comparatively so rare.

"Saccardo, P. A. Michelia, 1: 370.
16614— No. 36—02 2

18 THE "BLUING" AND THE "BED ROT" OF THE PINE.

The growth and development of the fungus may be briefly noted as
follows:" The spores of the "blue" fungus (PL VII, 8) are probably
blown about by the wind in countless thousands, and at the time of the
beetle attack in July and August some of these spores lodge in the
holes made in the bark of the living pine tree by the bark and wood-
boring beetles. The atmosphere of these holes is constantly kept
moist by the water evaporating from the trunk. In these holes the
spores can germinate within a day after falling there.

In drop cultures of pure water the spores germinate readily over-
night. The hyphre grow into the bark tissues and into the cambium,
and from there they enter the cells of the medullary rays. The readi-
ness and rapidity with which the hyphse grow into the medullary rays
lead one to suspect that the food substances, stored in the medullary
rays at this period of the year in considerable quantities, exert a
chemotropic stimulus. In the early stages of development one finds
the hyphse of the "blue " fungus only in the medullary ray cells. After
a hypha has entered one medullary ray cell it branches and spreads to
the" neighboring cells (PL VII, l" and 2; PL VIII, figs. 1 and 2), so
that in a very short time the entire ray is filled with the hyphae, most
of which grow in the ray toward the center of the trunk. Numerous
starch grains are usually found in the ray cells during the early part
of August; these are rapidly dissolved by the fungus and serve as a
source of food supply for a considerable period of time. The hyphae
are at first colorless, very thin-walled, and full of vacuoles and oil
globules. They branch rapidly, forming numerous septa. If the
starch supply is abundant, hyphre several microns in diameter may be
formed (PL VII, 2). These are constricted at the septa and show signs
of rapid development. The older hyphse turn brown, and with the
first signs of the brown color in the hypha? the bluish coloration of
the wood begins. One of the first effects seen after the hyphse have
entered the medullary ray cells is the gradual solution of the walls
separating the medullary ray cells from one another (PL VII, 1, 2,
and 3). The walls which separate the ray cells from the neighbor-
ing wood cells may become very thin, as shown in the middle ray
(PL VII, 1), but they are rarely dissolved entirely. The intermediate
walls, on the other hand, entirely disappear. This leaves a tube with
a cross section having the shape of the cross section of the ray, extend-
ing into the trunk from the bark. This tube is sometimes filled
entirely with a mass of brown hyphse, the larger number of which
extend in the direction of the ray (PL VIII, figs. 1 and 2). From the
ray cells some h}Tpha3 make their way into adjacent wood cells (PL VII,
2; PL VIII, figs. 1 and 2). They grow along these, both up and down

« A fuller discussion of its cultural characteristics, spore germination, and the blue
color will l>e printed at a later date.

THE '"BLUE" FUNGUS. 19

(PL VII, 1), giving off branches to other wood cells. a In this manner
the whole wood body becomes penetrated by the brown hyphae in a
very short time after the first infection. The number of hyphae in the
wood cells proper, i. e., excluding the medullary ray cells and the
cells of the wood parench}Tina, is very small indeed. This is proba-
bly due to the fact that the fungus finds scant material upon which to
live in the wood cells. The hyphae are apparently able to puncture
the unlignified walls here and there, but they stop at that point. The
writer was not able to demonstrate that the hyphae could attack the
lignified walls. In other words, the " blue " fungus is one which confines
its attack to the food substances contained in the storing cells of the
trunk and to the slightly lignified walls of these storing cells. The
best instance of the resistance which the lignified walls offer to the
dissolving action of the hyphae is found in the outer walls of the medul-
lary rays, which are composed in part of the more heavily incrusted
walls of the adjacent wood fiber.

The resin ducts are attacked in much the same manner as the medul-
lary rays. (PL VII, 3; PL VIII, fig. 2.) The walls of the component
cells are dissolved, leaving a tube filled with brown hyphae. When
looked at with a low-power magnifying glass, a cross section of the
wood shows the resin ducts as black spots in the wood ring.

The rate at which the hyphae advance in the medullary rays keeps
them considerably in advance of the hyphae in the wood cells and also
of the blue color which follows the appearance of the hyphae in the
rays. When the hyphae have reached the heartwood they cease grow-
ing inward. One reason for this may be the absence of food materials
in the rays of the heartwood, and another may be the greater lignifica-
tion of the heartwood cells. It is very certain that the hyphae do not
flourish in the heartwood, neither in the medullary rays and resin ducts
nor in the wood cells proper. Hartig ascribes the restriction of the
fungus to the sapwood to the smaller amount of water in the heart-
wood, but it would seem to the writer that there would hardhr be so
very sharp a line between the points where growth does take place
and where it does not, if it were a matter of water supply alone.
The readiness with which the fungus can enter heartwood and sapwood
cells and the presence or absence of food substances would seem to be
factors of more importance in determining the regions where the
fungus could or would not grow.

The growth in the medullary rays comes to a stop within six months
after the first infection, and perhaps earlier. This applies to such
wood as is infected in July or August. By December or January the
whole sapwood will be filled with hyphse. In the top of the tree the

« The hyphse growing out from the medullary rays, as shown in PI. VIII, fig. 2,
make the wood cells appear septate. This, of course, is not the case.

20 THE "BLUING" AND THE "BED EOT" OF THE PINE.

development is probably very similar, although it was not possible to
make an accurate determination of this fact because of the great
irregularity in the rate with which infection takes place after the
beetle attack. The rate of growth in the trunk varies considerably.
Some trunks are invaded on all sides with equal rapidity; some, on the
other hand, seem to be more resistant on one side or another. A good
idea as to the presence or absence of the fungus can usually be obtained
by observing the extent of the blue coloration, to which reference is
made below.

EFFECT OF "BLUE" FUNGUS ON THE TOUGHNESS OF THE " BLUE " WOOD.

On page 13 it was stated that the "blue" wood was considered
very much tougher than the healthy wood. The tie cutters in the
Black Hills find that it is very much harder work to cut cross-ties from
the "black-top" wood than from green trees — so much so that they
demand additional pay for cutting these ties.

When split with an ax, the two halves of a block seem to hang
together more firmly, and it requires more strength to wedge them
apart. Chips do not fly off as easily. The only explanation which
can be suggested for this peculiar behavior of the diseased wood is
that in the t; blue" wood we have an enormous number of filaments, all
extending radially through the wood. These filaments occur in
bunches, much interwoven, scattered at regular intervals through the
wood. It is estimated that at a point about 1 foot in from the bark
there are about 39,000,000 medullary rays per square meter of tangen-
tial surface, or about 3,700,000 per square foot. Even if the tensile
strength of one hypha is not very great, when it comes to 4,000,000
bundles these may have some effect in holding masses of wood fiber
together (see Plate VIII). This view is strengthened by the fact that
it seems easier to split the "blue" wood along radial lines than on
tangential lines. In making ties the tangential cut is used almost
entirely, and it is possible that these hyphal bundles are responsible
for the toughness. When split tangentially and viewed edgewise, one
can see some of these hyphal bundles projecting from the medullary
rays, as if they had been pulled out and stretched before being torn.

RELATION OF THE "BLUE" FUNGUS INFECTION TO THE BEETLE HOLES.

As has been previously stated, the first evidences of the presence 6f
the "blue" fungus are seen some weeks after the beetles have bored
into the cambium layer. The first signs of blue color in the wood
might be expected just under a hole in the bark or near such a hole,
or under the tube excavated in the bark extending from such a hole.
This, however, is not always the case; in fact, is rarely the case. The
small triangular patches of color may appear anywhere within the area

THE '"BLUE" FUNGUS. 21

attacked by the beetles. Why this should be so it is difficult to explain
satisfactorily. The spores must enter the region between the wood
and the bark through the beetle holes and burrows, for there is no
other way for them to get through the bark. Cracks in the bark are
practically entirely wanting in the living trees. The only explanation
possible is that the h}Tphae start their growth in the bark and cambium
layer, the parts richest in food materials, and then grow inward at one
or more points independent of the beetle holes.

As soon as the living bark and wood die, a wood-boring beetle enters
the wood and makes numerous small holes all through the sapwood
(see PL IX). It enters felled trees within a few days after the tree is
cut. The holes which it makes extend radially into the trunk, some-
times with great directness, then again obliquely. The beetles bore
with great rapidity, so that they may have reached the heartwood in
the course of a few months. These holes form very convenient chan-
nels for the entrance of the hyphse of the "blue" fungus, and the^
take advantage of their opportunities. Before they appear in the
wood cells surrounding the holes made by the wood-boring beetle,
one finds great masses of another fungus in the open ends of the wood
cells bordering the hole. This is the so-called " ambrosia" fungus,0
which the beetles carry into the holes with them, and upon the spores
of which they feed. The hyphse of this fungus are colorless and
thick walled. They extend into the wood cells away from the holes
only a short distance, but near the holes they grow into dense mats,
which practically plug the lumen of the wood fibers toward the beetle
hole. The bunches of sporophores with the round pores project into
the beetle hole from these mats.

The hyphse of Ceratostomella can be distinguished readily from those
of the " ambrosia" fungus. They are thin walled, full of vacuoles, and
turn brown very soon. There seems to be no relation between the
two, although such a relation is not impossible. The development of
the "ambrosia" fungus is now being investigated, and it is hoped that
this study will throw more light on any possible relation.

This class of beetle probably carries the spores of Ceratostomella
with it into the holes it makes, much as it carries the "ambrosia " spores.
This seems probable from the fact that the " blue " fungus seems to start
at various points along a beetle hole ; in other words, it does not grow
down into the hole from the outside. Sections made at right angles to
the hole show that the fungus starts to grow on all sides of the hole,
and that it makes most rapid headway in a direction parallel to the long
axes of the wood fibers (PI. IX). When once the hyphse have reached
the medullary rays from the wood fibers, progress in all directions

« Hubbard, H. G. The Ambrosia Beetles of the United States. Bull. 7, n. s.,
Division of Entomology, U. S. Dept. of Agriculture, 1897, pp. 9-30.

THE *4 BLUING AND THE 44KED EOT OF THE PINE.

becomes equally rapid. The blue color appears around the beetle
holes soon after the entrance of the "blue" fungus. Usually it forms
two rings extending from the hole along the wood fibers. Various
stages of this first appearance of the color are shown on PI. IX. The
spread of the "blue" fungus within the wood, through the agency of
wood-boring beetles, is an occurrence frequently found in many conif-
erous woods. The central figure at the bottom of PI. IX is from a
photograph of a log of western hemlock found in the Olympic Forest
Reserve, in Washington, which shows an even more striking case of
the spread of Ceratostomella from holes made by Gnathotricus ocd-
dentalis Hopkins MS. This particular piece of wood was cut from
a fallen trunk, about 6 inches in from the bark.

FRUITING ORGANS OF THE ;4BLUE" FUNGUS.

The "blue" fungus forms its fruiting bodies on the surface of the
wood in which it is growing. Air seems to be necessary for the for-
mation of the fruiting bodies. A good deal of moisture in the sur-
rounding air is necessary likewise. No fruiting organs are formed in
dry air. In the forest they occur in the cracks formed when a blued
trunk is broken off, on broken branches, and at such other points as
are exposed to the air. So far the writer has been unable to find the
perithecia of Ceratostomella on the surface of standing trunks under
the bark, although a diligent search has been made for them at all
seasons for two years. When, several months after the beetle attack,
the bark becomes loose, so that it separates from the wood, a space
is left between the bark and wood. In this space numerous fungi
develop in quantities, among others a species of Altemaria which lines
the pupal chambers of the Dendroctonus, and a species of Verticillium.
The whole atmosphere of this region is surcharged with moisture, and
yet the ' ' blue " fungus does not fructify here, for there is probably
not enough air.

The black perithecia of the "blue" fungus, Ceratostomella pilif era
(Fr.) Winter, are familiar objects on blued boards or shingles, where
they occur in thousands side by side. The perithecia are formed
within a few hours when the conditions are favorable. At various
points on the surface of the wood, in some instances out of every
medullary ray, masses of hyphas grow out forming a dense mass which
gradually develops into an egg-shaped body (PL VII, 4). The surface
of the young perithecium shows irregular polygonal markings, which
gradually become indistinct as the perithecium turns jet black almost
to its tip. At the tip of the young perithecium a number of hyphse
grow out parallel with one another (PI. VII, 4) in a direction perpen-
dicular to the substratum. They remain colorless at the tip. These
hyphge grow in length with remarkable rapidity and form a long

THE "BLUE" FUNGUS. 23

bristle-like neck several times as long- as the diameter of the perithe-
cium (PL VII, 6). This neck becomes very brittle as soon as the peri-
thecium is mature, and breaks off at the slightest jar or touch. The
tips of the hyphre composing- the neck remain joined at the top until
the spores are discharged; they then separate and form a sort of cup-
shaped support for the spore mass (PL VII, 9). The body of the peri-
thecium when mature is about 180^ in diameter and 160/* high, and is
covered with scattering brown hyphae. The neck averages about 1,050,/u
in length and 20/* in thickness.

The spores of Ceratostomella are elongated and somewhat curved
(PL VII, 8). They are very small, and the asci in which they are
borne are almost round or egg-shaped (PL VII, 7) and exceedingly
evanescent, so much so that it is very difficult to find them. Hun-
dreds of perithecia in all stages may be examined without showing
a sign of asci. When the spores are mature, they are discharged
through the neck, either in the form of a large drop (PL VII, 5, s),
or in a long, worm-like mass. The spores are held together by a
mucilaginous material, which will not mix with water. It is suggested
that this serves admirably to spread the spores through the agency of
crawling insects and worms, both common on wood where the peri-
thecia are likely to be found. The spores germinate in water after a
few hours, sending out a short hyaline germ tube, which branches
very soon after its appearance. The discharge of the spores takes
place when a certain amount of moisture has accumulated within the
perithecium. A rain storm often brings about a worm-like discharge
from ripening perithecia. In cultures a globular discharge takes place,
probably because of the more equitable distribution of water. The
spores measure 5.5/< by 2.5/*, average.

GROWTH IN ARTIFICIAL MEDIA."

The "blue" fungus grows quite readily in artificial media. In pine
agar the mycelium develops rapidly; less so in ordinary agar or gela-
tin. Cultures are most readily obtainable in pure condition by inoc-
ulating pine agar tubes with pieces of blued wood removed (with care
so as keep them sterile) from the inner portion of a blued log. The
hyphie grow out from the blued pieces and soon grow through the
agar to the surface. On nearly all cultures of this character peri-
thecia developed on the surface of the agar within a week. The asco-
spores germinate in a few hours, and at the end of thirty-six to forty-
eight hours a colorless mycelium bearing large numbers of conidiahas
developed. At first these conidia were regarded as contaminations,
but their repeated appearance in cultures made from pure cultures of the

« The cultural work was carried on in conjunction with Mr. George G. Hedgcock,
assistant in pathology.

24 THE "BLUING" AND THE "RED ROT" OF THE PINE.

ascospores leaves no doubt as to their being- a stage of the "blue"
fungus. Cultures made from these conidia developed a mycelium on
which both conidia and perithecia appeared. Work with these conidia
is .-till in progress and a report upon the results accomplished is to be
published in full at a later date.

In four to five days in good growing cultures on rich pine agar or on
sterile pine blocks the older threads of the colorless mycelium begin
to turn brown, and at the end of seven to nine days young perithecia
begin to form. These are at first hyaline and change rapidly from
brown to black. They mature quickly, and at the end of from twelve
to eighteen days some will be found ejecting the ascospores. In twenty-
one days nearly all perithecia in a culture will be mature.

DISSEMINATION OF THE SPORES.

The sudden appearance of the "blue'' fungus on lumber piles and
over large areas at once, and its simultaneous appearance within the
trunks of the pine trees seem to point to the distribution of the spores
of the fungus b\r the wind. It was thought that the bark beetles might
be instrumental in carrying the spores into their holes. This the}7
might do by having the spores adhering to their bodies or by feeding
on the spores and depositing these in their holes. To test these hypoth-
eses, beetles were placed in tubes of melted pine agar, thoroughly
shaken, and then plated. Quite a number of beetles were dissected
and cultures were made, using their alimentary canals, as well as some
of their feces, as infecting material. In none of these cultures did any
"blue" fungus appear. A very characteristic bacterium was obtained
from the alimentary tracts, but no Ceratostomella. A number of live
beetles (Dendroctonw*) were allowed to walk about on pine agar plates,
but no "blue" fungus developed. These trials are by no means to be
regarded as conclusive, for they were not exhaustive. They are to
be repeated on a larger scale this winter and in the summer when
the beetles emerge. The number of perithecia developing on dead
sticks and in cracks is sufficient to account for an}T infection which
takes place in the Black Hills forest. This applies with equal force
to all regions where the "blue" fungus occurs.

The months of May, June, July, and August are the ones during
which the most rapid development of this fungus takes place.

THE BLUE COLOR.

Wood in which the mycelium of Ilelotium seruginosum (and prob-
ably of other "green" fungi) grows turns green very soon after the
fungus gets into the wood. As shown by Vuillemin and others, the
green color is due to a substance formed as a product of metabolism
of the fungus, which is deposited in the form of regular granules in

THE "BLUE77 FUNGUS. 25

the hyphre and fruiting bodies of the fungus. The green matter,
xjTlindeine, is confined to the fungus threads and- in no wa\T stains the
wood fibers. Vuillemin states expressly (p. 1-M) that "there is no
green decay or green staining of the wood. The wood appears green
when the colored thallus of Helot'mm seruginosum or of analogous
fungi is found in its elements." With the highest powers of the
microscope he was unable to find any coloration of the walls of the
wood. The green color is therefore due to the presence en masse of
green -colored threads.

Similar instances of color due to the presence of colored mycelium
are found on pine and spruce wood, where brown and black lines are
formed by masses of dark hyphse bunched at particular points in the
wood cells. The familiar zigzag and fantastic line's often found in
wood of the tulip tree and in birch and maple are due to similar fungus
threads. In none of these cases are the wood fibers themselves colored.

So far as known to the writer, no attempt has ever been made to
explain the nature of the blue color of coniferous woods. The color
is a difficult one to define. A number of the writer's artist friends
who were called into consultation pronounced it a blue gray, approach-
ing Payne's gray. Freshly cut wood looks decidedly blue, but as the
wood dries the color fades somewhat and dry wood is mouse gray.
The color is by no means regular; here and there some of the yellow
of the healthy wood shines through. The drawing shown on PI. I is
perhaps a little too blue. PI. V is closer to the real color. Certain
portions of the blued wood look greenish when viewed obliquely.

There are two possible explanations as to the cause of the so-called
blue color: (1) The wood may appear colored because of the pres-
ence of the colored fungus threads in the wood. The mass effect of
such colored threads might make the wood appear colored. (2) The
wood might be colored by a pigment or stain formed either by the
fungus or as a result of the fungus growth in the wood, and this
pigment might stain the walls of the wood fibers.

The first explanation holds good for the "green" wood. Here a
pigment is formed in the hyphse and fruiting bodies of the fungus, and
it is because of the presence of the green-colored bodies in the fungus
threads, according to Vuillemin, that the entire wood looks green.
Careful examinations made of the "blue" wood by persons trained to
observe colors, called into consultation by the writer, have led to some-
what conflicting results, and it is therefore thought inadvisable in the
present stage of the investigation to enter on a lengthy discussion of
the color subject. A number of facts may be stated, however. Exam-
inations of the wood fibers of sound and "blue" wood showed that it
was possible in most instances to distinguish between the sound and
the "blue" wood. The walls of the sound wood look somewhat
darker (with a suggestion of purple) than the blued fiber. This method

2G THE " BLUING" AND THE "RED ROT" OF THE PINE.

of examination, with high magnification, is a rather uncertain one,
however, for the refraction caused by the containing liquids, which
are purplish, and of light falling from a blue sk}T, is apt to show very
faint traces of color which do not belong to the wood. It may be
stated definitely that the fibers of the " blue" wood show no indication
whatever of any color element seen in the wood en masse.

The hyphre constitute the only color element present in the "blue"
wood which could not be detected in the sound wood. These are
present in the medullary rays and adjacent cells, as described above.
These hyph» are pale reddish-brown, a color which may be obtained
by taking a pale tinge of warm sepia. This color is very distinct and
stands out in sharp contrast to the surrounding yellow wood fibers.
(See PI. VIII, showing the contrast.) How these brown hyphae could
make a blue gray or mouse gray it is difficult to understand, for no
density of such a brown, even in combination with straw yellow (of
the wood fiber), could possibly produce blue gray. It would there-
fore seem probable, or at least possible, that there is some pigment
with a blue element in the "blue" wood which is so faint that its
detection in thin microscopic sections becomes almost impossible.

All efforts to extract any color of a blue nature from the wood have
so far failed. Extracts of blued wood with ether, alcohol, benzol,
chloroform, alkalis, and acids gave evidence that changes of some
sort had taken place in the wood fiber, for the extracts of sound and
" blue" wood differed materially in nearly every instance. No signs
of any blue or blue-gray color were obtained.

It seems necessary, therefore, to leave this matter for further inves-
tigations, which are now in progress.

SUMMARY.

In the foregoing chapters a peculiar disease of the dying wood of
the bull pine has been described. The wood turns blue in August and
September, after the trees are attacked by the beetles. The blue color
starts near the base of the tree and gradually spreads upward until
the entire sapwood is blue. The "blue" wood is somewhat tougher
than the healthy wood and has been shown to be practically as strong
as the healthy wood.

DECAY OF THE "BLUE" WOOD.

The changes which the "blue" fungus brings about in the wood of
the western yellow pine can hardly be called decay. It is true that
the medullary rays are destroyed in part and that the walls of many
wood fibers are punctured, but as a whole the wood is sound in the
ordinary acceptance of that term. It is not rotten, or doty, or decayed.
The "blue" fungus attacks cell contents and not the cell walls.

DECAY OF THE " BLUE 7 WOOD. 27

After the wood has been dead for some time certain changes begin,
which in the end result in the entire decay of the wood. The dead
wood may or may not be blue, for the processes by which the wood
changes to decayed wood are the same for wood which is entirely
healthy and for the "blue" wood.

THE "RED ROT" OF THE WESTERN YELLOW PINE.

The "red rot " of the western yellow pine usually starts in the tops of
the "black-top" trees, i. e. , trees which have been dead for two or more
years. At one or more points, usually on the north or east side of a tree,
one will find that the wood immediately under the bark starts to rot.
This rot starts at the bark and gradually extends inward (PI. X, fig. 1).
The wood when it shows the first signs of this decay is wet and soggy
and rapidly becomes brittle, so that it crumbles into small pieces when
rubbed. A plane will no longer make a smooth surface (PI. X, figs. 1
and 2), for the knife tears out small pieces of the wood fiber. The
color of the wood changes from blue to red yellow. When the decay
has gone on for some time, bands and sheets of a white felty substance
are found filling certain cracks which result because of shrinkage in
the wood mass (PI. X, fig. 2). These white sheets consist of masses of
fungus threads densely interwoven. The destruction of the wood con-
tinues until the heartwood is reached, and as this is exceedingly small
in the tops of these trees one will find that after some time almost
the entire wood mass has changed to a brown, brittle, resistless mass
(PL XI). The completely rotted wood crumbles into a fine powder
when crushed between the fingers. When wet it is of a cheesy con-
sistency. When the water has evaporated from such wood it is like
so much brown charcoal.

The "red rot" of the dead timber is caused by one of the higher
fungi which grows in the wood, and by so doing brings about the decay
of the wood. The spores of this fungus fly about in the forest and
some of them lodge in bark crevices of the dying trees. The numerous
beetle holes afford every opportunity for entrance to the wood, and it
is therefore not surprising to find that the majority of the "black-top"
trees become infected sooner or later with the spores of this fungus.
The spores germinate and hyphie grow into the dead cambium and the
wood, where they attack such organic matter as has been left by the
"blue" fungus. They go farther, however, and attack the cell walls
of the wood fibers, from which they extract the cellulose. As a
result of this, the wood fibers shrink in volume and crack in regular
lines extending obliquely across the cell walls. As the solution of the

28 THE "BLUING" AND THE ''RED ROT" OF THE PINE.

cellulo.se goes on, large numbers of fibers separate in a body from the
adjoining ones, often along the lines of medullary rays, and the space-
so formed are rapidly tilled with fungus threads, giving rise to the
white sheets already spoken of. (See PL X, fig. 2.)

CONDITIONS FAVORING THK DEVELOPMENT OF THE "RED-ROT." FUNGUS.

One of the most important factors which influences the development
of the "red-rot" fungus, and one which holds for all fungi, is water.
If the trees in the Black Hills were dry, the red rot would make but
slight progress. At the time when the attack takes place the trees are
full of water, especially the tops, for these have lived longer than the
butts of the trees, and water was pumped into them long after the
lower parts of the trees were dead. The top, therefore, is the most
favorable point for the " red-rot" fungus, and it is there that it is
found developing most rapidly. From the top the fungus may grow
down, so as to affect the lower part of the trunk, but as this has been
drying continuous!}' since the beetle attack one will find that it is. very
rare for those parts of the trunk situated at points 5 to 30 feet from the
ground to be seriously injured by this fungus in the first years after
the death of the trees. This is an exceeding^ important considera-
tion when the practical phase of this subject is taken into account.

The relation of the water supply to the " red rot" is illustrated very
well in the large number of trees where the bark has died and peeled
off from one side of the tree. On PL X, fig. 2, a photograph of such
a case is reproduced. The bark has fallen off on the south and south-
west sides of the tree, but it still is attached to the opposite side. The
result of this peeling becomes evident very soon, for on that side the
wood dried very rapidly, while on the other side the bark prevented
such evaporation. The wood remained moist, and here the "red-rot"
fungus found a footing and conditions favorable for its growth. The
result was that in the course of some months the north and northeast
sides of that trunk were completely deca}Ted, while the opposite side
remained sound. A similar instance is shown in the largest section on
PL VI, fig. 2; in this case at the base of the tree.

Where the bull pine grows on hillsides not exposed to the sun or
wind, or where there is much undergrowth, one will f requently find
the "red-rot" fungus entering the trees at the base before it attacks
the top. This is likewise due to the fact that the water has not left the
trunk with sufficient rapidity to prevent the attack.

FINAL STAGES AND FRUITING ORGANS.

When the tops become rotted almost to the heart they become so
weak that they are broken off by the first wind. In those sections of

DECAY OF THE " BLUE " WOOD. 29

the Black Hills Forest Reserve where the beetle attack took place some
four or more years ago there are thousands of dead trees standing with
their tops broken off much like- those shown in Pi. XII. In this view
the tops can be seen tying on the ground. PL XIII, fig. 1, shows the
lower end of one of these tops. One will note how sharp it has broken
off — almost straight across. One of the sheets of mycelium has curled
over at the extreme right of the figure. The cross sections of such a
top (reproduced on PL XI, figs. 1 and 2) show how completely the wood
has been destroyed and that there is small chance for such a top remain-
ing on the tree very long.

Where the u red-rot" fungus attacks the tree at its base it brings
about the decay of the larger roots underground, and also of the sap-
wood of the trunk close to the ground (PL VI, fig. 2, large section,
and PL XI, fig. 3). After a time the roots become weakened to such
an extent that they are no longer able to keep the trunk in an upright
position, and the result is that the tree is blown over. Such a fallen
tree is then attacked rapidly at all points by the "red-rot" fungus,
and in a few years nothing is left of it but a pile of rotted wood.

When the wood has been completely destroyed the fruiting organs
of the " red-rot" fungus begin to form. Some of the hyphse grow out
through the bark and form a flesh-colored knob (PL XI, fig. 1), which
rapidly increases in size and turns reddish in color. This knob grad-
ually widens horizontally, forming a shelf, and on the lower side of
this shelf numerous pores appear. One of these bodies is seen grow-
ing out from the fallen top shown on PL XIII, fig. 1, a little below
and to the right of the small branch extending out toward the front
of the picture. (See also PL XI, fig. 2, and PL XIII, fig. 2.) After a
year a mature fruiting body or sporophore (commonly called a punk,
mushroom, or toadstool) has developed, from which spores are dis-
charged at intervals. These spores are formed in the small tubes
found on the lower side of the sporophore, and on a quiet night one
can see them coming from the sporophore in white clouds as they are
being discharged in countless thousands. The spores are so light that
they are carried many miles by the winds and lodge on every stick and
tree in the vicinity.

The sporophores of this fungus may grow for many years. At dif-
ferent periods, the length of which is not yet definitely known, they
add a ring on the outside and thereby increase in size. The one shown
attached to the section on PL XI, fig. 2, is probably 2 years old, while
the one at the base of the tree on PL XIII is probably several years
old. The sporophores may occur singly or in groups of two or three
together. When a top falls so as to lie close to the ground where it
is likely to be kept wet, the sporophores will develop every few inches,
so that there may be as many as 20 or 30 on a log 10 feet in length. On

30 THE "BLUING" AND THE "RED EOT" OF THE PINE.

standing trees they occur only at the base of the trees (PL X11I).
Here they grow close to the ground and oftentimes their lower surfaces
are actually in the ground. Grass, pine needles, and stones almost hide
the entire sporophore.

Older punks are rough on top and appear to be covered with some
waxy substance which has hardened and cracked. This substance,
when scraped, resembles a hard resin. It is brittle, and is readily
soluble in alcohol and xylol. It has a sticky appearance, and when
freshly formed on the younger parts its bright red color forms a distin-
guishing character not readily overlooked. The younger parts are
sometimes flesh color, then again reddish yellow in color, and as they
grow older they turn more decidedly red. The surface is at first
smooth and waxy, and as the sporophore grows older it becomes very
much wrinkled. The outer waxy covering cracks (PI. XIII, fig. 2),
and the whole surface then seems to be coated with a dull gray, lime-
like substance, which is exceedingly characteristic.

The red-rot fungus belongs to the Hymenomycetes, genus Polyporus
(Fomes), and differs decidedly from other species of this genus. The
species most closely related to it are Polyporus pinicola and Polypwm
marginatus. Its whole appearance, its color, hard resinous covering,
and very rough surface distinguish it from these species. It has been
decided to consider it as a new species — Polyporus ponder osus, n. sp.—
which ma}r be described as follows:

A large Polyporus of the Fomes type usually growing singly (PI. XI, fig. 2), some-
times two or three together (PI. XIII, fig. 2), broadly applanate; about as thick in
the back as it is wide (PL VII, figs. 10 and 11) ; top, when young, flesh-colored to
yellow red, becoming darker red with age; smooth when young, rapidly becoming
rough and covered with irregular nodules. Older specimens show numerous ridges,
formed by regular additions (annual) on the edge and below. Top covered after
the first year with a hard, brittle, dull, resinous substance, which cracks as it grows
old, and looks sandy or crystalline. Lower surface smooth, pores very regular,
almost round, extending out to a line which is about one-fourth inch in width. (See
PI. VII, figs. 10 and 11.) Common on dead trees and fallen logs of the western
yellow or bull pine ( Pinus ponderosa ) in South Dakota.

RATE OF GROWTH OF

The question as to the rate of growth of the " red rot " is one of great
practical significance. The "red rot" fungus is the principal cause
which prevents the dead wood from lasting indefinitely. It usually
attacks the trees when the}r have reached the "black-top" stage; i. e.,
toward the end of the second year after the beetle attack, and there-
after. The larger number of trees are probably free from this rot
until the third year. To make this clearer, one may make a schedule
of the stages through which the trees go, about as follows:

AMOUNT OF DISEASED TIMBER. 31

1899, July. — Live trees attacked by the bark-boring beetles.

1899, September. — Wood of the lower part of the trunk starting to blue.

1899, December. — Wood blue to the heart below, and wood of the top partially
blue.

1900, May. — "Sorrel-top" stage; leaves turning yellow; wood wholly blued.

1900, October. — " Red-top" stage; leaves red and lower ones starting to fall off;
wood blue, but sound.

1901, May. — "Black-top" stage; leaves falling off and fallen wood starting to
decay; "red rot" in the tops.

1901, October. — "Black-top" stage; leaves all fallen; top badly decayed and in
many instances broken off.

This calendar must be considered a tentative one, based upon obser-
vations of two years, although in the main it is probably correct.
The " red-rot " part is extremely variable, and can not be assigned to any
definite period. The time when the tops will begin to decay is depend-
ent upon the weather at any particular season, the amount of rain, the
vigor of the tree and the length of time it takes the tree to die com-
pletely after the beetles have attacked it, the position of the tree in
the forest, the prevailing winds, and probably other factors more or
less related to those mentioned.

It is exceedingly important that this variability be recognized, for
its bearing on the cutting and utilization of the dead timber is of the
greatest importance. There may be ' ' black-top " trees which will be
sound from the ground to the very top, and these trees may have
stood in the forest for years in this condition. Not far awa}r one will
find others which have barely reached the "black-top" stage which may
show signs of decay to within a few feet of the ground. It is there-
fore entirely impossible to lay down a hard and fast rule, and to state
that the " black tops" after a year are all of no value as timber.

The average conditions in the Black Hills are certainly very favor-
able for the development of "red rot," and one will probably not be
very far from the truth when he assumes that after the trees have
reached the ' ; black-top " stage they are liable to decay and deteriorate
within a comparatively short time; that time probably will not exceed
two years.

AMOUNT OF DISEASED TIMBER.

In the foregoing, but brief reference has been made to the actual
condition of the forests in South Dakota at this time and to the extent
of the injury following the attack of the bark beetles. The amount of
dead wood, both standing and fallen, is very large, and as the beetles
are still at work, it is steadily increasing. It is, of course, rather dif-
ficult to make estimates of the exact amount without an actual survey
of the whole region. A trip through the worst region — i. e. , north of
Spearfish River and west of the Burlington Railroad tracks — was made
during the past summer, in company with several expert timbermen,

32 THE "BLUING" AND THE "RED ROT" OF THE PINE.

for the purpose of determining about how much dead and dying tim-
ber one could safely count on removing this winter. Estimates were
individual, and these estimates (' agreed fairly well as to the relative
amounts of the various grades of timber present. Taking these
e>timatex a> a basis, it appears that about half of the timber in this
particular region is now dead. This refers to the standing timber, and
leaves the fallen timber entirely out of consideration. This immense
amount of timber is drying out rapidly and forms a tremendous fire
danger. Should fire start in these woods, it would sweep the dead as
well as the living trees from the hillsides. The great danger of leaving
the trees with the beetles in them, which will be " sorrel tops'1 next
summer, has been pointed out by Hopkins. Besides these two dangers,
there is still another point worthy of attention, and that is the loss,
under present conditions, of the value of this wood. The following
considerations are made, keeping in mind both the protection of the
living timber against further insect and fire loss and the possible
utilization of the vast amount of dead timber.

POSSIBLE DISPOSAL OF THE DEAD WOOD.
IN THE BLACK HILLS.

Timber from the Black Hills Forest Reserve is now being used by
tne mining interests in the Hills, and to a very small extent by the rail-
roads on their lines in South Dakota. The mining interests use the
wood for mine props, lagging, and fuel. They are absolutely depend-
ent on the timber in the Reserve for the lumber necessary for use in
mining, for their fuel, and for their water, which is conserved because
of the forests on the hillsides. The railroads use the wood for cross-
ties on the lines which extend from Lead City and Deadwood south to
the State line. The timber used for mine props, lagging, etc., by all
the mines in the Black Hills is stated to be about 75,000,000 feet at the
maximum. The amount of timber used for ties is practically inap-
preciable, and at this writing most of the tie cutting has practically
stopped.

It appears from this that the amount of dead timber which could
po->ibly be used in the Black Hills is not more than 75,000,000 feet.

"The exact estimates were as follows:

Kind of timber.

I. II.

in.

< i IV.-M timber

Per cent. Per cent.

Per cent.

"Sorrel tops "

OR Oft

"Red tops"

20 ' I'S

f e

"Black tops '

I'S 90

The third estimate was made by Dr. Hopkins and the writer.

VALUE OF THE DEAD WOOD INSPECTION. 33

IN THE REMAINING PARTS OF SOUTH DAKOTA.

The Black Hills are situated in the extreme southwest corner of
South Dakota, and the only railroad connection which they have with
the surrounding territory is southward into Nebraska. It is there-
fore entirely impracticable to consider a possible use of any of the
dead timber in parts of South Dakota outside of the Black Hills.

It appears from the foregoing that only a very small amount of the
dead timber can be used in the Black Hills, and that practically none
can be taken to other parts of South Dakota. The only practicable
method of disposing of this surplus amount would be to ship it out of
the State, but this is not permissible under the present forest-reserve
law, as will be pointed out hereafter.

VALUE OF THE DEAD WOOD.

The dead wood which ought to be removed from the Black Hills
Forest Reserve is of all grades and values, and for practical purposes
it is impossible to draw any lines grading the same which will hold
good. It must be taken for granted that the only wood which can be
considered as worth anything at all is wood which shows no sign of
decay or rot. Most of the timber, in fact nearly all, will be blue. The
blue color, as has been previously shown, ought not to make much
difference as regards its strength, and if properly treated with pre-
servatives it is probable that the "blue" wood will be serviceable for
ties and lagging.

The wood which is dead in the forest now rots rapidly, as has been
pointed out, and every day that it is left makes large amounts of it less
valuable than it was before. At best one may expect that timber which
is killed by the beetles one year will begin to deca}^ after two years.

In fixing the price of this dead timber it should be remembered that
in order to get it out, lines of railroad would have to be constructed
at a very considerable cost. Even with such lines the cost of bringing
the dead timber from the forest to points where it could be utilized
would be great. The expense of bringing timber from Montana and
Wyoming to Nebraska (such cost including the first cost of the timber
plus the transportation) will about equal the cost of bringing the tim-
ber from the Black Hills to Nebraska. That the wood must have some
value to be worth going for at all is obvious, but, as has been pointed
out, its value will depend upon the rapidity with which it is removed.

INSPECTION.

One of the greatest difficulties which will be encountered in the
utilization of the dead timber will be in connection with the inspec-
tion of the material used. There will be vast quantities of the timber

16614— No. 36—03 3

34 THE " BLUING7' AND THE "RED ROT77 OF THE PINE.

which will be hard and sound, but badly blued. Then again, if the
recommendations as to the cutting of live trees which are infested
with beetles are followed there will be timber which will in all
respects be like the green timber. A tie cut from the top of a tree in
September, after the beetle attack in August, will usually be perfectly
healthy, i. e., it will show no traces of blue color or only very slight
ones.

All timber which is entirely sound, i, e., not decayed, is fit for the
uses to which it can be put in the Northwest, either for mine timbers,
lagging, ties, etc. The blue color is not to be considered as a sign of
decay. Timber which shows rotten spots of any size in the sapwdod
should not be used. An idea of what such decayed spots look like can
be gained by studying the photographs reproduced on PI. X, figs. 1 to
.3, and PI. XIV, fig. 1. Besides the defect caused by the u red rot,'- one
will sometimes find logs which show decay in the center. This is a
disease of the living tree, and when more than one or two rings are
affected by the disease, such logs should likewise be rejected. The tie
section shown on PI. XIV, fig. 2, is an example of this form of rot.

A careful and intelligent inspector who familiarizes himself with
the causes of the decay in the Black Hills Forest Reserve ought to
have no difficulty in determining after some practice which timber is
fit for use and which ought to be rejected. No amount of chemical
treatment will, so far as we now know, make a practicalhr decayed log
serviceable.

RECOMMENDATIONS.

Bearing in mind the considerations just referred to, the following
recommendations are made:

(1) Removal of wood from the forest. — The dead timber should be
removed from the Black Hills Forest Reserve at once. It forms a
standing fire menace. The standing beetle-infested trees serve to
spread the insect trouble. This dead timber should be removed at
once, or at the earliest possible moment, and the living infested trees
should be felled and peeled as recommended by Dr. Hopkins, for with
every day the situation becomes more and more difficult to handle.

(2) Sale of wood. — In order to rid the forest of danger from fire,
from further insect and fungus spread — in other words, in order to
protect the remaining living trees from further destruction — the dead
wood should be removed. The cost of operation in removing the
dead timber is very considerable: (1) Because of the distance from
lines of transportation; (2) because of the greater difficulty in cutting
this wood; (3) because of the scattered localities in which it is found;
(4) because of the constant care and selection necessary to get good
sound wood. Therefore, because of this increased cost, it is recom-
mended that the dead and beetle-infested timber be sold at a nominal

RECOMMENDATIONS. 35

price to such as may apply therefor, this to be done in order to induce
persons to assist in clearing the forest with all possible speed.

(3) Removal from South Dakota. — It has been pointed out that the
great mass of dead timber now in the Black Hills Forest Reserve can
not be used in South Dakota. It is therefore recommended (again as
a measure of protection for the living forest) that the forest-reserve
law be so amended as to permit the shipment of the dead and beetle-
infested timber from the State of South Dakota.

In making such a change, it ought to be understood that shipping
timber from the State should in no way interfere with the industries
dependent upon such timber in the State where the timber is situated.
The case under consideration is an example in point. The mining
interests of the Black Hills are absolutely dependent for their timber
supply on the wood in the Black Hills, and if any timber is removed
from the region of the Black Hills, i. e., from the State of South
Dakota, it should be taken from regions in the Black Hills which are
no Tributary to the important mining interests in the Hills. In other
words, if any timber is removed from the Black Hills, it should come
from the region south and west of the Little Spearnsh River.

(4) Timber which should be removed. — The timber which should be
removed is the dead and beetle-infested timber. For the purposes of
inspection dead timber should be considered as timber which comes
from trees whose leaves are no longer green — that is, the "sorrel tops,"
the "red tops," and the "black tops." " Beetle -infested timber" has
been specified by Dr. Hopkins.

This dead timber will be "blue timber," and 'much of it is now
decayed. Contractors should be required to cut and remove only such
timber as is perfectly sound, without any signs of decay.

PLATES.

37

DESCRIPTION OF P1.ATES.

PLATE I. — Frontispiece. Cross section of the trunk of a dying tree of the western
yellow or bull pine (Pinus ponderosa) from the Black Hills, South Dakota. This
tree was attacked by the beetles in August, 1901. The section was cut at a point
6 feet from the ground during the early part of November, 1901. Note the beetle
holes in the bark; also the yellow ring between heartwood and sap wood.

PLATE II. — Dying trees of the bull pine. Fig. 1 shows several trees; at the left two
live, green trees, a "sorrel-top" tree in the center, and a "red-top" tree at the
right. Photographed August 5, 1902. Fig. 2 shows several live, green trees at
the left and a "sorrel-top" tree toward the right. Note that this tree is still
green at the top. Photographed August 5, 1902.

PLATE III. — Various stages showing the gradual color change of leaves of the bull
pine (Pinus ponderosa) after they have been attacked by the bark beetles (Den-
droctonus ponderosx ) . 1 . Leaves from a healthy tree. 2. Leaves from a 4 ' sorrel-
top" tree. 3 and 4. Leaves from trees changing to the "red-top" stage. When
the leaves have reached the stage of 4 they fall off and are completely dead.

PLATE IV. — Fig. 1. Group of bull pines (Pinus ponderosa) near Elrnore, S. Dak.,
showing a " red-top " tree in the center and healthy trees on both sides. Fig. 2
shows a group of "black-top" trees from which all leaves have fallen. This
photograph was made in November, 1901, and it is probable that these trees
were attacked by the beetles in August, 1899.

PLATE V. — Sections of trunks of the bull pine (Pinus ponderosa), showing the
"blue" disease. Fig. 1 shows an early stage. This section was cut in Novem-
ber, 45 feet up in the trunk, from a tree attacked by the beetles in August of
the same year. The tree is still alive at this point. The blue color has started
at two separate points. Fig. 2. A later stage, showing the blue color spread out
over one-half of the section. Note the yellow ring at the border of heartwood
and sapwood.

PLATE VI. — Fig. 1. Three sections from a bull pine made in November, 1901. This tree
was probably attacked by the beetles the latter part of July, 1901. The sections
were made at points 5 feet, 16 feet, and 36 feet, respectively, from the ground,
i. e., the largest section was cut from the butt, the second one about half way up,
and the third in the top. The healthy wood photographs white, and all darker
shades represent blued wood. Note the beetle holes in the bark. Fig. 2.
Three sections from a bull pine made in November, 1901. This tree was prob-
ably attacked by the beetles in July, 1900. It is a " black-top" tree. The sec-
tions were made at points 4 feet, 26 feet, and 40 feet from the ground. All are
blue. The section near the ground shows " red rot." This happens frequently
where the bases of the trees are shaded by long grasses and bushes. In most
trees the base will be found sound. The whole tree was dead.

PLATE VII.— Mycelium and fruiting bodies of the "blue" and "red-rot" fungi. 1.
Tangential section of "blue" wood; m, cross sections of hyphae of the blue fungus
( Ceratostomella. pilifera (Fr.) Winter), growing in the medullary rays; h, hyphse
growing longitudinally in the wood fibers. These hyphse are brown. 2. Cross
section of "blue" wood, showing longitudinal section of medullary ray with
hyphse of the " blue" fungus (h) growing in the ray and into adjoining cells; the
38

DESCRIPTION OF PLATES. 39

ray cells have been destroyed; m, cross sections of hyphse of Ceratostomella pilifera.
3. Cross section of a medullary ray, with resin duct showing the internal cell
walls wholly dissolved out. Masses of brown hyphse, m, of the ''blue" fungus
extend longitudinally through the ray. 4. Young perithecium of the ' ' blue ' ' fun-
gus ( Ceratostomella pilifera (Fr. ) Winter), grown on pine agar culture. 5. Mature
perithecla of the " blue" fungus ( Ceratostomella pilifera (Fr.) Winter), grown on
pine agar culture, showing the spores, s, discharging from the top of the beak.
The line at the side equals 0.1 mm. 6. Two perithecia of the " blue " fungus
( Ceratostomella' pilifera ( Fr. ) Winter) just before the discharge of the spores. Peri-
thecia from culture on pine wood. 7. Two asci with spores of the ' ' blue ' ' fungus
( Ceratostomella pilifera (Fr. ) Winter). 8. Spores of the " blue " fungus ( Ceratosto-
mella pilifera (Fr.) Winter). 9. Top of beak of perithecium of Ceratostomella
pilifera (Fr. ) Winter, just after the discharge of the spore mass. The hyphae
composing the tip of the beak have spread out, forming a sort of support for the
spore mass. 10 and 11. Median sections of sporophores of the "red-rot" fungus
( Polyporus ponderosus, n. sp. ) , natural size.

PLATE VIII. — Photomicrographs showing the structure of "blue" wood. Fig. 1. A
radial section, showing how the hyphse of the "blue" fungus grow in the medul-
lary rays, being confined almost entirely to the rays. Magnification, 80 diame-
ters. Fig. 2. A tangential section, showing how the hyphse completely fill the
medullary rays. Numerous small hyphae grow out into adjoining cells in a
tangential direction. This makes the wood cells in the photograph look as
if they were septate. The apparent septa are hyphre. Magnification, 80
diameters.

PLATE IX. — A number of pieces of wood from the bull pine (Pinus ponderosa) , show-
ing holes made by wood-boring beetles. The trees from which these pieces were
taken were in most cases dead, either standing or felled. The "blue" fungus
has started to grow in the wood cells bordering on these holes, and is gradually
spreading to other cells from these holes as a center. Note that these wood
pieces show both radial and tangential surfaces. The piece of wood in the
center at the bottom of the plate is western hemlock.

PLATE X. — Sections of "black-top" trees of the bull pine (Pinus ponderosa) , showing
early stages of the "red rot" caused by Polyporus ponderosus, n. sp. Fig. 1.
Section of a dead tree 35 feet up from the ground. This tree had probably been
dead for eighteen months to two years. The decay has just started in at several
points on the north and northwest sides of the tree. Note that the larger part
of the wood is blue. The healthy, unaffected wood is white. Note also the
beetle holes in the bark. Fig. 2. A section from a similar ' ' black-top ' ' tree,
showing a more advanced stage of decay. The whole section was blue. The
decay started on the side where the bark prevented the rapid evaporation of
moisture from the wood and had reached the heartwood. Note the radial and
tangential sheets of white mycelium. Fig. 3. A section from the same tree from
which fig. 2 was taken, made some 15 feet higher up. The section is blue, but
shows few signs of decay. This shows how the "red rot" usually attacks the
tree somewhere below the crown.

PLATE XI. — Sections of "black-top" trees of the bull pine, showing advanced stages
of decay caused by Polyporus ponderosus n. sp. Figs. 1 and 2. These two sections
were cut from a fallen top of a "black top " such as is shown in PI. XIV, fig. 1,
one near the point where the top broke off, the smaller one near the top of the
crown. Both show how completely the wood has been destroyed. This stage
was probably reached about three years after the beetle attack. Fig. 3. The
lower figure shows a section cut 4 feet from the ground from a standing " black-
top" pine. On one side a fruiting body of Polyporus ponderosus is to be seen,

40 THE "BLUING" AND THE "RED ROT" OF THE PINE.

which is probably two years old. The sapwood is wholly converted into a
brown, brittle mass. Such a tree is liable to be blown over at any time.

PLATE XII. — A group of "black-top" trees of the bull pine near Elmore, S. Dak.,
showing how the tops break off after the trees have been dead for some time.
Many of the tops are visible, lying near the base of the trees. A single "black
top" from which the top has not fallen is seen at the left. The standing trunks
are decayed for several feet downward from the point where the top broke off.
The base ot these trunks is generally sound, and contains enough timber to make
a good cross-tie.

PLATE XIII. — Fig. 1. View of a broken top, showing how it has broken off almost
straight across. Near the middle of the figure a fruiting body of the " red-rot "
fungus (Polyporus ponderoms, n. sp. ) is growing out. Fig. 2. Base of a dead bull
pine (Pinus ponderosa) near Elmore, S. Dak., showing a number of fruiting
organs of the "red-rot" fungus (Polyporus ponderosus, n. sp.) growing out from
the wood. These are the bodies variously known as "punks," "toadstools,"
"mushrooms," or "frogstools." The double one to the left is very old. Note
the cracked upper surface. A section of the trunk made at the point where
these bodies are growing out would appear much like PI. XI, fig. 3.

PLATE XIV. — Sections of the ends of two cross-ties cut from dead timber, showing
defects which are so serious that ties of this kind should be rejected. Fig. 1.
Defective because of the "red rot." Fig. 2. Defective because of a disease of the
living timber.

Bui. 36, Bureau of Plant Industry, U. S. Dept. of Agriculture.

:

PLATE II.

,1

.36, Bureau oF Plant Industry, U. S. Dept. of Agriculture.

Plate

COLOR CHANGES IN LEAVES OF THE BULI_PINE

i. Leaves from healthy tree. 2. Leaves from "Sorrel-top" tree.
3 and, 4. Leaves from trees turning of the "Red-top" $ta-ge.

Bui. 36, Bureau of Plant Industry, U. S. Dept. of Agriculture.

PLATE IV.

H

33

m
n m

ll

Bui. 36, Bureau of Plant Industry, U. S. Dept. oF Agriculture .

Plate V.

SECTIONS OFTRUNKS OFTHEBULLPINE, SHOWING EARLYSTAGES OF"BLUE DISEASE".

Bui. 36, Bureau of Plant Industry, U. S. Dept. of Agriculture .

Plate V.

Pig. I.

SECTIONS OFTRUNKS OF THE BULL PINE, SHOWING EARLYSTAGES OF"BLUE DISEASE"

Bu,. 36, Bureau of Plant Industry, U. S. Dept. of Agriculture.

PLATE VI.

FIQ. 1.— SECTIONS FROM TREE DEAD FIVE MONTHS.

FlQ. 2.-SECTIONS FROM TREE DEAD EIGHTEEN MONTHS.

"BLUE" SECTIONS FROM DEAD TREES.

Bui. 36, Bureau of Plant Industry, U. S. Dept. of Agriculture

PLATE VII.

MYCELIUM AND FRUITING BODIES OF "BLUE" AND "RED-ROT" FUNGI.

1, Tangential section of "blue" wood; 2, cross section of "blue" wood: 3, cross section of a medullary ray;
4, young perithecium of the "blue" fungus (Ceratottomclla pit if era); 5, mature perithecia of the "blue"
fungus; 6, two perithecia of the "blue" fungus; 7, two asci with spores of the "blue" fungus; 8, spores
of the "blue" fungus; 9, top of beak of perithecium of Ceratantnm<'lla pilifera just after the discharge of
the spore mass; 10 and 11, median sections of sporophores of the "red-rot" fungus Poli/porus ponder-
osus, n. sp.).

Bui. 36, Bureau of Plant Industry, U. S. Dept. of Agriculture.

PLATE VIII.

FIG. 1.— RADIAL SECTION.

FIG. 2.— TANGENTIAL SECTION.
SECTIONS OF "BLUE" WOOD.

Bui. 36, Bureau of Plant Industry, U. S. Dept. of Agriculture.

Plate IX.

PIECES OF WOOD FROM THEBULI.PINE;SH©WING BLUE FUNGUS STARTING FROM
HOLES MADE BY A WOOD-BORING BEETLE.

Bui. 36, Bureau of Plant Industry, U. S. Dept. of Agriculture.

PLATE X.

FIG. 1.— SECTION TAKEN 35 FEET FROM THE GROUND FROM A DEAD TREE.

FIQ. 2.— SECTION SHOWING MORE ADVANCED STAGE FIG. 3.— SECTION FROM TREE SHOWN IN

OF DECAY. FIG. 2, MADE 15 FEET HIGHER UP.

EARLY STAGES OF "RED ROT."

Bui. 36, Bureau of Plant Industry, U. S. Dept. of Agriculture.

PLATE XI.

FIGS. 1, 2.— SECTIONS FROM THE TOP OF A FALLEN TREE.

FIG. 3.— SECTION FROM A STANDING PINE, 4 FEET FROM THE GROUND.

SECTIONS FROM "BLACK-TOP" WESTERN YELLOW PINE TREES,
SHOWING ADVANCED STAGES OF DECAY.

Bui. 36, Bureau of Plant Industry, U. S. Dept. of Agriculture.

PLATE XII.

GROUP OF BROKEN "BLACK-TOP" TREES.

Bui. 36, Bureau of Plant Industry, U. S. Dept. of Agriculture.

PLATE XIII.

FIG. 1.— TOP OF "BLACK TOP" BROKEN OFF.

FlG. 2.— POLYPORUS PONDEROSUS GROWING ON DEAD PlNE STUMP

Bui. 36, Bureau of Plant Industry, U. S. Dept. of Agriculture.

PLATE XIV.

FIG. 1.— WOOD AFFECTED WITH "RED HOT.'

FIG. 2.— DISEASED WOOD FROM LIVING TREE.
SECTIONS OF REJECTED CROSS-TIES.

BULLETINS OF THE BUREAU OF PLANT INDUSTRY.

The Bureau of Plant. Industry, which was organi/ed July 1, 1901, includes Vege-
table Pathological* and Physiological Investigations, Botanical Investigations and
Experiments, Grass and Forage Plant Investigations, Pomological Investigations,
and Gardens- and Grounds, all of which were formerly separate Divisions, and also
Seed and Plant Introduction and Distribution, The Arlington Experimental Farm,
and Tea Investigations and Experiments.

Beginning with the date of organization of the Bureau, the independent series of
bulletins of the several Divisions were discontinued, and all are now published as
one series of the Bureau.

The bulletins issued in the present series are:

No. 1. The Relation of Lime and Magnesia to Plant ( Growth. 1.901.

2. Spermatogenesis and Fecundation of Zamia." 1901.

3. Macaroni Wheats. 1901.

4. Range Improvement in Arizona. 1901.

5. Seeds and Plants Imported through the Section of Seed and Plant Intro-

duction. Inventory No. 9, Nos. 4351-5500. 1902.

6. A List of American Varieties of Peppers. 1902.

7. The Algerian Durum Wheats: A Classified List, with Descriptions. 1902.

8. A Collection of Economic and Other Fungi Prepared for Distribution. 1902.

9. The North American Species of Spartina. 1902.

10. Records of Seed Distribution and Cooperative Experiments with Grasses

and Forage Plants. 1902.

11. Johnson Grass: Report of Investigations Made During the Season of

1901. 1902.

12. Stock Ranges of Northwestern California. 1902.

13. Experiments in. Range Improvement in Central Texas. 1902.

14. The Decay of Timber and Methods of Preventing It. 1902.

15. Forage Conditions on the Northern Border of the Great Basin. 1902.

16. A Preliminary Study of the Germination of the Spores of Agarieus Campes-

tris and Other Basidiomycetous Fungi. 1902.

17. Some Diseases of the Co wpea. 1902.

18. Observations on the Mosaic Disease of Tobacco. 1902.

19. Kentucky Bluegrass Seed: Harvesting, Curing, and Cleaning. 1902.

20. Manufacture of Semolina and Macaroni. 1902. ,

21. List of American Varieties of Vegetables. 1903.

22. Injurious Effects of Premature Pollination. 1902.

23. Berseem: The Great Forage and Soiling Crop of the Nile Valley. 1902.

24. The Manufacture and Preservation of Unferrnented Grape Must. 1902.

25. Miscellaneous Papers. 1902.

26. Spanish Almonds and Their Introduction into America. 1902.

27. Letters on Agriculture in the West Indies, Spain, and the Orient. 1902.

28. The Mango in Porto Rico. 1902.

29. The Effect of Black Rot on Turnips. 1903.

30. Budding the Pecan. 1902.

31. Cultivated Forage Crops of the Northwestern States. 1902.

32. A Disease of the White Ash Caused by Polyporus Fraxinophilus. 1903.

33. North American Species of Leptochloa. 1903.

34. Silkworm Food Plants. 1903.

35. Recent Foreign Explorations, as Bearing on the Agricultural Development

of the Southern States. 1903.

ivi a K. c i :->

Syracuse, N. V.
PAT. JAN 21, 1908

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