A Clover Fungus. 



47 



an account of it, describing it first as Sclei'otinia trifolioruvi* 

 He states that it was brought there with clover seeds, and it 

 appears that it is periodically somewhat troublesome in that 

 country. In Denmark it was originally observed in 1870 by 

 Professor Rostrup, who has from time to time written con- 

 cerning the fungus and its attacks, and, in 1890, contributed 

 an illustrated article thereon to the Ugeskrift J or Landni(End:\ 

 The Professor in courteous answer to a question in May, 1898, 

 says : " It is everywhere in Denmark a very frequent and 

 injurious parasite on clover." Sclerotinia tri'foliorttmwsis first 

 discovered in the United States at the Agricultural Experi- 

 ment Station of the Delaware College in 1889, when Mr. 

 Chester, the mycologist at that station, stated that it was 

 apparently new in that country, and furthermore that its stay 

 was transitory, so that there was little time at disposal for 

 intelligent observation. J Mr. Albert Woods, the acting Chief 

 of the Division of Vegetable Physiology and Pathology of the 

 United States Department of Agriculture, wrote in April, in 

 answer to inquiries concerning Sclerotinia trifoliorum in 

 America, that " the trouble has been observed quite often in 

 this country and does considerable damage here." 



From the evidence that is obtainable respecting the host 

 plants of Sclerotinia trifolioruvi it is clear that trefoil 

 [Medicago lupulina), or " Black medick," is the most 

 commonly infected. Red clover comes next to trefoil 

 in liability to infection, while white clover is the least liable. 

 Rostrup states that in Denmark trefoil, Afedicago lupulinay 

 or " gulklover," is especially subject to this attack, and advises 

 that it should not be included in mixtures of seeds for clover 

 leys. 



As the attack has only been recognised recently in 

 England, no estimate can be made of the liability of 

 particular species here. It is certain, however, that red 

 clover, alsike, and Trifolium incariiatum were alike infected. 

 It was also noticed upon yellow trefoil [Medicago lupuhna) in 

 a pasture where this clover is usually most abundant. 



* 0)n Klbfverrbtaii. Jakob Eriksson. Stockholm, 1880. 



t Rloverens Bcegersvainp. Sclerotinia trifolioriuu. Docent E. Rostrup. 

 Kjobenhavn, 1890. 



+ Sixth Report of the Agricultural Experiment Station of Delaware College^ ^^93' 



