Dec- 1896.] INJURIOUS INSECTS AND FUNGI. 283 



A Lily Disease (Polyactis [Botrytis] cana). 



Complaints have been received during the summer from growers 

 of lilies concerning a prevalent and serious attack of a fungoid 

 character upon these plants. The leaves turned brown just 

 before the flowering period, and the flowers themselves either 

 became rusty in colour as they developed, or were so affected by 

 the fungus that they did not develop fully. The varieties 

 principally affected were Lilium candidum, Lilium umbellatum, 

 and Lilium auratum. The disease also appeared upon Lilium 

 lancifolium in greenhouses. In some cases the whole crop of 

 lilies grown for market purposes was ruined, and in one 

 neighbourhood the cultivation of lilies has been stopped in 

 consequence of this affection. Plants from bulbs recently 

 imported from Holland were also attacked by this fungus, and 

 a great quantity of tulips were spoilt by it, or at all events by a 

 similar fungus. No infected tulips have been submitted for 

 ■examination, but it was reported that they were attacked in 

 exactly the same manner as the lilies. 



The first indication of this disorder is the appearance upon 

 the leaves of small rusty spots, which gradually spread over 

 them and extend to the buds- and flowers. In some cases the 

 b>uds become deformed by the rapid action of the fungus, and 

 are prevented from coming into full flower ; in other cases the 

 flowers are blotched or blurred with brown patches, and rendered 

 useless for cutting. In course of time the leaves fall from the 

 plant, and the flowers become shrivelled, blackened, and utterly 

 useless. 



Examination of the infected leaves and flowers revealed the 

 presence of a fungus whose filaments covered the surfaces with 

 glistening branches, surmounted by the peculiarly shaped 

 conidiophores, bearing spores or conidia. It is a beautiful 

 fungus when seen in its earlier stages and while it is still 

 glistening. After a time the branches change to a brown colour. 



Professor Marshall Ward has made a special study of this 

 fungus, and has given a most elaborate account of it in 

 *< Annals of Botany" (Vol. II, pp. 319-382). He has also 

 -described it in his useful handbook of ' c Diseases of Plants," in 

 which he says that " the Botrytis, or Polyactis, is only one 

 phase in a very complicated life history." From the mycelium, 

 or vegetative centre of the fungus, hard black bodies are formed 

 called sclerotia, " balls of hyphae produced by the repeated 

 branching and knotting up of the ends of the branches of the 

 mycelium. ... In the case of the lily fungus the sclerotia 

 are somewhat irregular in size and shape, and shining black." 

 The sclerotia are, as Prof. Marshall Ward points out, of the 

 utmost importance to the fungus, " for when all the rest of the 

 mycelium has been killed off by dry, cold weather, they remain 

 uninjured through the frosts and snow of the winter, and the 

 hard, black, outer coat of the sclerotium keeps alive the inner 



