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CORTICIUM (PENIOPHORA) CHRYSANTHEMI 
By Charles B. Plowright, M.D. 
With Plate 6. 
Some five-and-twenty years ago | planted a number of Chry- 
santhemum plants on the south side of a wall in a small strip of 
freshly broken up garden ground in King’s Lynn. Chrysan- 
themums in those days were not what they are now and the varie- 
ties planted were intended to be permanent ornaments, of the 
garden. In the course of a few years they died off, one after 
another. On examination of the plants it was observed that in 
each case a white fungus growth was present on the lower 
part of the stems. This growth resembled a splash of white- 
wash. It was not confined to the stems but extended into the 
adjacent soil. At first it was regarded as some form of white 
mould of a saprophytic nature, for at that time but little was 
known of the parasitic character of the Hymenomycetes. For 
several years attempts made to grow Chrysanthemum plants in 
this garden failed. Closer examination and more careful watch- 
ing made it evident that the fungus was a Corticium bearing a 
close external resemblance to C. sambucz, Its fullest develop- 
ment was attained upon the base of the stems. It never 
extended far upwards above the ground level and it was noted 
that the white hyphe not only matted the particles of earth 
together but that they extended in many cases from stem to 
stem. Plants once attacked did not survive beyond the second 
year. 
The young green shoots sent up by affected plants in the 
autumn are shorter in height and thinner in the stem. Expert 
ence shows that when once a plant is attacked it is of little use 
attempting to remove the healthy portions and induce them to 
grow for the ensuing season’s blossoms. They almost invarr 
ably succumb within the year. During the autumn of 1904 the 
disease was met with in two other gardens in the town, which 
led to its more careful examination, as a fungus of such 
destructive capabilities cannot fail to be interesting to hort 
culturists. 
The stroma of the hymenophore is lax, the individual hyphe 
being easily demonstrated in a section, especially upon its lower 
surface. When growing in living bark they can be seen to pass 
between the cells of the host. 
The hymenium is smooth to the unaided eye but irregular 
