DISEASES OF CULTIVATED PLANTS 403 
IRIS 
Bulb-Spot. Massey has reported a fungus causing black patches on 
the surfaces of iris bulbs. This fungus (J/ystrosporum aductum Mass.) from a 
description given, resembles onion smudge in its appearance and effects. Loss 
is prevented by soaking the bulbs for an hour in Formalin solution. 
Leaf-Blight. The leaves and roots of iris have been reported in England to 
be attacked by a fungus. (Botrytis galanthina Mass.) This disease is likely 
to be present in shipments of iris about the world. It is described as first 
attacking the leaves and later destroying the root, thus causing the death of the 
plant. 
IVY 
Leaf-Spot and Leaf-Blight. Leaf diseases of English ivy are occasionally 
reported but have not been studied for our district. Dr. Halsted has described 
a blight upon variegated forms of Englishivy (Vermicularia trichella Hals. ). 
In this connection we need to bear in mind that variegated plants are especially 
susceptible to disease and are therefore liable to suffer. 
JAPAN CREEPER 
See Virginia Creeper. 
LARCH 
Canker and Rots. Larches are but little grown in ourterritory. In Canada 
there has been described a larch canker ( Peziza willkomii Hartig.) This attacks 
the trunk and branches. In common with other conifers the larch suffers from 
tree infecting rot fungi. The lack of American data upon these diseases empha- 
sizes our need for such studies. 
LEMON 
Greenhouse specimens of lemon trees are a source of a good many in- 
quiries. These are chiefly leaf diseases which arise from the brown molds and 
other fungi infesting these plants. As a rule they are amenable to spray 
treatments with standard fungicides. 
Rots. Allusion has been made to storage and transit rots of citrus fruits. 
The lemon is no exception to the attacks of these rots. The blue mold 
(Penicillium) is a very common form, and may be met with inalmost any of the 
ordinary shipments of lemons. Brown-rot (Pythiacystis citrophthora R. E. Sm.) 
is a serious trouble in California lemons especially. It appears as a white 
mold on the surface of affected fruit. 
