238 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



The Dipsaceae contains only five genera, viz. Dipsacus, Gephalaria, 

 Knautia, Pterocephalus, and Scahiosa. Morina, formerly included in 

 this family, should in all probability be a member of a new family 

 embracing Moriaceae, Trilostegia, and Hoeckia, or form, together with 

 Acanthocalyx, a new division. — S. E. W. 



Diseases of Cereals and Grasses (U.S.A. Exp. Stn.. Ohio, 

 Bull. 203, April 1909; plates). — These investigations were under- 

 taken in order to try to discover the cause of the shrivelling which has 

 often been noted in wheat grains without the presence of attacks of rust 

 severe enough to account for the phenomenon. Experiments were 

 made with_the apparatus known as a physician's centrifuge, which was 

 found to answer the purpose admirably of detaching disease spores from 

 affected grain, and was the means of discovering the existence of a 

 hitherto unrecognized Anthracnose disease which attacks rye, wheat, 

 oats, and various grasses. 



The organism causing this disease has been provisionally given the 

 name of Colletotrichum cereale, and its life-history was studied upon 

 its natural hosts and in standard culture media in the laboratory, the 

 similarity of colony, form and size of spores, colour and appearance 

 of mycelium being apparent in all these growths. 



The spores of this disease are readily disseminated through seed- 

 grain, as is shown by the results of centrifugal examinations made of 

 the washings from suspected grain. Seed treatment with formalde- 

 hyde drench will destroy the Anthracnose spores; and during the 

 growing season formaldehyde, hot-water and corrosive-sublimate 

 treatments, which, were being tried for smut, were found to check the 

 Anthracnose disease also. 



Further investigation of this disease is, however, to be undertaken 

 by the Department with the co-operation of private growers. This 

 bulletin also contains information upon the wheat scab, Fusarium | 

 roseum (Lk.), and gives the results of cultivation of the spores of its j 

 probable perithecial form, Giherella Saubinelli (Mot.) Sacc. upon culture] 

 media. The work done demonstrated that the scab fungus not onlyj 

 survives in dead wheat kernels, but also in those capable of germina-j 

 tion. Germinations of externally sterile kernels of wheat have been 

 made in the Geneva germinator, in sterile tubes, and in soil in the 

 greenhouse. All these tests proved that the scab fungus (Fusarium), 

 under such conditions, was an aggressive seedling parasite attacking 

 and killing the young wheat plants when less than a month old. 

 Clover, oats, barley, rye, and spelt are also affected by an apparently 

 identical fungus. Some plots of wheat at the station were infected 

 w^ith washings of wheat, oats, barley, rye, the grain of which had 

 showed an abundance of scab conidia under centrifugal micro- 

 examination, and it appeared that, no matter which of these was the 

 source of the conidia, infection of the wheat readily took place. On 

 the practical side, it is pointed out that stinking smut, scab diseases, 

 and Anthracnose have all been found present in seed-grain, and there- 



