CONTRIBUTIONS FROM THE WISLEY LABORATORY. 213 



CONTRIBUTIONS FROM THE WISLEY LABORATORY. 



VI. — A Disease of Lavatera trimestris. 

 By F. J. Chittenden, F.L.S. 



Seveeal specimens of Lavatera trimestris have been received at the 

 Laboratory in a dead or dying condition in each of the past three years. 

 The first came from Alton, in Hampshire, and others subsequently from 



Fig. 81. — Colletotrichum mal varum. 



a, Leaf of Lavatera trimestris with brown spots caused by the fungus ; b, por- 

 tion of stem with diseased spot ; c, spores ; d, bristles which cause the dark 

 colour of the spots, (a and b slightly reduced, c and d greatly magnified.) 



widely separated localities, mainly in the south of England, though the 

 disease is not confined to any particular part of the country. 



The first symptom of the disease is the appearance of small yellowish- 

 brown spots on the upper surface of the leaves (fig. 81, a) and on the 



