618 The Trees of Great Britain and Ireland 
the stool, and cuttings from these had been grafted by a Cretan farmer on the 
ordinary plane tree and were preserving the evergreen habit. (A. H.) 
The stellate tomentum, which covers the young leaves of the plane, is gradually 
cast off; and floating in the air, has been found in some parts of Europe to produce 
serious bronchial irritation. This was known to the ancient Greeks,’ being 
mentioned by Galen and Dioscorides. In Alsace-Lorraine, the planting of plane 
trees is forbidden in the vicinity of schools ; and workmen in nurseries on the 
Continent, where young trees are raised, are often affected.” We have, however, not 
heard of any complaint of this happening in England. 
The young leaves and shoots of var. acertfolia are frequently affected by a 
disease caused by the fungus known as Gleosporium nerviseguium, Saccardo, 
which in early summer attacks the nerves first and soon causes them to wither. 
Small black spots appear on the dead parts, which are the conidia of the fungus. 
In England, it is remarkable that the true oriental plane appears to be 
practically immune from the attacks of this fungus, though its leaves are sometimes 
blotched between the veins. Mr. Massee informs us that after a thorough examina- 
tion of dried and living material, he has failed to find the slightest evidence in 
support of the statement that Gleosporium nerviseguium is parasitic on typical 
P. orientalis. The London plane is almost invariably affected, though less in 
London than in the country, where almost everywhere some of the leaves and 
young shoots become brown and wither; but the healthy growth of the tree is 
scarcely ever seriously interfered with. Some gardeners believe that this withering 
is due to cold winds and late frosts; but, though leaves may be injured by 
climatic conditions, this fungus is undoubtedly the principal cause. A plane tree, 
var. cuneata, in the Cambridge Botanic Garden, which had the habit of var. acerzfolia, 
had the leaves badly attacked in June 1907. A tree, 30 feet high, of the same 
variety, at Grayswood, had the young wood seriously injured by a fungus, which Mr. 
Massee identifies with Glwosporium. 
The fungus is apparently more severe in its attacks on the Continent; and at 
Ghent in 1891, all the plane trees lost their leaves. In the United States, the 
occidental plane® is very liable to be attacked by this fungus, and as a street tree 
in New England is unsuccessful on that account, though P. acerifolia succeeds as 
well as it does in England. 
Klebahn® states that Gleosporium nerviseguium occurs more especially on 
P. occidentalis, less frequently on P. orientalis. He believes that G. nerviseguium 
is only a conidial form of a higher fungus, called Guomonia Veneta, Klebahn. 
(Hy Je E.) 
: 2 eesti Sather boa pee ‘ : Carriére, Rev, Hort. 1890, pp. 370, 435. 
7 Ct Garden and Forest, 1891, “i 50 : Peas 51, and 1897 oe Ge aera ht of the Plane Tree 
by Morrill in Journ, N. York Bot. Garden, viii. 157 (e059), an seein is given of an epidemic of cs disease occurring this 
year in New York, believed to have been caused by the late and damp spring. Miurrill observed the oriental plane to be 
attacked in Italy in 1906; and states that P. racemosa is also subject to the disease. 
8 Jahrb. Wissensch. Bot, xii. 515 (1905) 
