55 



Black Mould in Corn. (Cladosporium Herbarum. Link.) 



(PLATE X.) 



This fungus is termed " common " by Mr. Cooke in his " Hand- 

 Look of British Fungi," and it was certainly common enough in 

 the season of 1892 in many corn-growing districts. In some 

 of these it caused serious harm to wheat, almost as much as 

 the ordinary mildew, Puccinia graminis. The Cladosporium 

 kerbarum, or " black mould in corn," as Mr. W. G. Smith well 

 describes it, was especially prevalent in the Eastern Counties. Mr. 

 Plowright says that " no district has probably suffered more from 

 than it the Eastern Counties." It was very injurious, however, 

 in Kent, Hertfordshire, Gloucestershire, and Hampshire, and, it 

 is believed, was very frequently taken for the ordinary wheat 

 mildew, Puccinia graminis. Badly blighted wheat fields were 

 examined, in which there were but few signs of Puccinia 

 graminis, the harm having been occasioned by the Cladosporium 

 herbarum, whose peculiar olive-brown conidiophores were easily 

 identified. The straw was infected by this fungus, and the ears 

 and the grains were especially attacked. In some cases the grains 

 were more shrivelled than those upon plants infested by Puccinia 

 graminis, and the Cladosporium was found in considerable 

 quantity upon the grains at the apex, or upper end, among the 

 fine hairs, or down, upon them. The ears had an unnatural 

 colour, so that one passing by infected fields could see at a glance 

 that the wheat plants were in an unhealthy state ; while observers 

 noted that the state and colour were not like those of wheat 

 plants infected with the ordinary mildew (Fig. 3.). There was 

 much brownish dust upon the plants, causing the labourers* 

 engaged in cutting the wheat with hooks, in the old-fashioned 

 way, to be, as a newspaper correspondent said, of the " colour of 

 Red Indians," and this dust was very annoying to the men with 

 the thrashing machines when the wheat was thrashed. Wheat 

 with downy chaff seemed to be especially affected. A field of 

 " velvet-eared white " in Kent was noted as being far more 

 affected and injured than smooth-chaffed varieties. 



Barley was also attacked by the Cladosporium herbarum. 

 Among the most striking illustrations of this novel attack were 

 specimens of infected ears of barley, taken from several fields in 

 Hertfordshire, forwarded by Mr. James Forbes, of Old Trinity 

 House, 4, Water Lane, Mark Lane, on the 26th of August. In 

 these ears the fungus had established itself on the apex, or upper 

 part, of the grain, at ti;e base of the long, bristling awns ; and, 

 as it appeared, upon the withered remains of the stamens. It 

 was most exceptional to find a grain without the fungus upon it 

 in the position shown by Fig. 1. Now and then a grain was 



