360 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 
A CONIFER DIsEAsE.1 
Quite recently a batch of diseased spruce seedlings was sent to 
the Royal Botanic Gardens, Kew, from upland Yorkshire, accom- 
panied by a statement that the disease was most prevalent at the 
crowded end of the seed-bed ; the portion where the plants were 
not so crowded appeared to be fairly free from it. Examination 
showed the disease to be caused by a fungus called Herpotrichia 
nigra by Hartig, who recorded it as an injurious parasite in the 
spruce woods of the Bavarian Forest. 
The leaves are attacked and killed by the fungus, but instead 
of falling when dead they are bound together by mycelium, and 
remain as a compact brown mass clustered round the branch 
from which they sprang. ‘These dense clusters of dead leaves, 
fixed to the branches by dark-coloured cob-web like mycelium, 
are very characteristic. The fruit of the fungus and also minute 
sclerotia are produced on the leaves. 
The parasite is most prevalent in nurseries at high elevations, 
and has been recorded as attacking spruce (Picea excelsa), moun- 
tain pine (Pinus montana), and juniper (Juniperus communis). 
It occurs in Germany and Norway. It does not appear to have 
been previously recorded in Great Britain. 
The following observations with a view to its prevention are 
made by Hartig:2—‘“It is an interesting biological point that 
the fungus grows, especially when the temperature is low, under 
the snow or during the time it is melting, because under such 
circumstances the air is completely saturated with moisture. 
The frequency of the disease at high elevations has led to the 
general adoption of the practice of forming spruce nurseries at 
low altitudes. It has also been found a good plan to look over 
the nurseries immediately after the melting of the snow, and to 
raise up all prostrated plants in order that they may be exposed 
to the wind. It would also be a step in the right direction in 
planting out trees to set them on hillocks and similar elevations, 
and to avoid placing them in hollows and other depressions.” 
It is important that diseased seedlings should be collected and 
destroyed by burning, otherwise the numerous fruits and sclerotia 
1 Reproduced from the Journal of the Board of Agriculture for June 1905, 
by permission of the Controller of His Majesty’s Stationery Office. 
2 Text-Book of Diseases of Trees (Hartig and Somerville, English ed., p. 76). 
