Vol. 5, No. II.J 
JOURNAL OP MYCOLOGY. 
[June, 1889 
GL(EOSPORIUM NERVISEQJJUM, (ECKL.) SACC. 
By E. A. Southwokth. 
The sycamore blight caused by the fungus Glceosporium nervisequum 
has been very abundant in various parts of the country for the past 
few years. In some cases trees have been killed outright by the disease 
and in many the growth of the early part of the year has been com¬ 
pletely destroyed. The sycamore is extensively planted as a shade tree, 
and its wood is used almost exclusively for making tobacco boxes. It 
is stated that one mill on the Embarras River in southern Illinois has 
within a few months received orders for 11,000,000 feet of sycamore 
lumber, and that other mills throughout that region are busy sawing up 
the great trees. If this demand continues it will soon be necessary to 
take some steps to keep up the sycamore supply, but when the trees 
are attacked each year with a destructive disease their existence is seri¬ 
ously threatened. Effects of the disease are so prominent that during 
and soon after its active season trees which have been affected can 
be readily distinguished for a long distance. Fortunately for the trees, 
the disease continues active only a small portion of the year, and 
during the greater part of the summer they have a chance to partially 
recover from the disastrous effects of the attack. But even under 
these favorable circumstances, it is evident that the growth is greatly 
^retarded. Last spring the disease attacked full-grown and young 
leaves, mostly near the ends of branches. Sometimes the young un- 
lignified stem was attacked at some distance from the end, and then, 
of course, all the leaves beyond this point would wilt, although no fun- • 
gus could be discovered on them. The petioles were very commonly 
attacked. The trees thus diseased had a scorched and wilted appear¬ 
ance. 
This spring the attack in Washington was quite different. Compara¬ 
tively few full-grown leaves were affected, but the external leaves of the 
unfolding buds showed the disease'as soon as they were half out, and 
many entire buds died before they were fairly open. In other cases the 
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