164 
Journal of Mycology 
[Vol. 11 
Figs. 25-31. Phyllachora junci (Fr.) Fuckel on Juncus effusa. 
25. Host showing the stroma. 
26. Cross section of stem of host showing perithecia. 
27. Ascus showing ascospores before the last division in the spores. 
28. Ascospores in'process of dividing. 
29. Ascospores after final division. 
30. Ascus with sixteen ascospores. 
31. Paraphysis. 
BLACKSPOT CANKER AND BLACKSPOT APPLE ROT. 
W. H. LAWRENCE. 
Macrophoma curvispora Peck; Torry Bot. Club, Vol. 27, 21 
Ja. 1900. Gloeosporium malicorticis Cordley; Bot. Gaz. Vol. 30, 
No. 1, p. 57, Jl. 1900. Myxosporium curvisporum (Peck) Sacc. 
in litt. 
Blackspot Canker 1 fungus like bitter rot fungus causes 
a disease of both the tree and fruit. It differs from bitter rot, how¬ 
ever, in that the canker stage does by far the greater amount of 
damage. This stage during the past few years has become very 
prevalent in the Maple Ridge and Mission districts of British 
Columbia and in Western Oregon and Western Washington in 
localities where the rainfall is considerable during the latter part 
of autumn and early winter. 
In January, 1903, numerous decaying apples were found 
among stored fruit. A few pustules were present in some of the 
decaying areas. Later the epidermis overlying each pustule splits 
open exposing a central mass of creamy white spores. These 
spores were typical of the Blackspot Canker fungus except they 
were a little larger. Inoculations were made to determine the 
relation of the canker and rot. The fungus grown from decaying 
apples was placed in apple twigs with positive results. Spores 
taken from pustules in cankers placed on uninjured epidermis of 
the fruit also gave positive results in most cases. 
The first indication of the presence of the fungus is a slight 
discoloration of the flesh of the apple just beneath the epidermis. 
The flesh becomes a light brown color and this is marked enough 
to be seen by the naked eye. As more flesh becomes involved the 
color becomes deeper brown. The epidermis makes a correspond¬ 
ing change in color. Decaying spots become depressed, dry and 
leathery. Pustules soon begin to make their appearance at the 
point of infection. The pustules are usually arranged in concen¬ 
tric circles about the point of infection — the more rapidly the 
1 Blackspot or Apple Canker; C. V. Piper, Ranch & Range, 8 Mr. 
1900. Apple tree Anthracnos; A. B. Cordley, Bull. 60 Oregon Agr. Exp. 
Sta. Ja. 1900 and Bot. Gaz. Vol. 30, No. 1, p. 57, Jl. 1900. Blackspot Can¬ 
ker; W. H. Lawrence, Bull. 66 Wash. Agr. Exp. Sta. 1904. 
