May 31, 1924 
Common Brown Rot of Fruits 
959 
development is so slow that the medium becomes too dry for further growth. 
If differences in reaction to artificial culture media alone are to be considered 
of specific significance, then the American fungus should be regarded as made 
up of several species. If, in addition to these cultural differences, the slight 
morphological differences exhibited by germinating conidia be considered, the 
separation of the European and American forms into two species is much more 
defensible. From a practical point of view this is very objectionable, however, 
because it would make impossible the specific identification of any except living 
material. It may be that further investigations, particularly of the ascogenous 
stages, will reveal important morphological differences, but until such differences 
are noted, it would seem much more logical and much more practicable to con¬ 
sider the American form and the European form as a single species having the 
name Sclerotinia cinerea (Bon.) Schrot. 
SUMMARY 
The common “brown-rot ” fungus of America has been given at various times the 
following names: Oidium fructigenum, Monilia fructigena, Sclerotinia fructigena, 
Sclerotinia fructicola , Sclerotinia cinerea f Sclerotinia cinerea forma americana , 
Sclerotinia americana. By examination of type specimens it is shown that 
Sclerotinia fructicola (Winter) Rehm, described by Winter in 1883 under the 
name of Ciboria fructicola , is identical with the ascogenous stage of the American 
brown-rot fungus, thus sustaining the contentions of Pollock. If it is assumed 
that the American fungus is different from the European form commonly known 
as Sclerotinia cinerea (Bon) Schroter, then its name should be Sclerotinia fructi¬ 
cola (Winter) Rehm, the first name known to be applied to any stage of it and 
also the first name applied to the ascogenous stage. If the American form and 
the European are considered identical, then the name should be either Sclerotinia 
cinerea , if one believes the first known name properly applied to any stage should 
be adopted as correct, or S. fructicola , if it is believed that the first known 
name properly applied to the ascogenous stage should be considered the correct 
one. The known differences between the two forms are chiefly physiological 
as revealed by differences in growth on artificial media. It is shown that the 
American strains may show differences in their reaction to culture media at least 
as great as those between strains from America and Europe respective^. It is 
believed that at the present time the known differences between the American 
and European forms are not sufficiently great to warrant considering the two 
forms as separate species. The name Sclerotinia cinerea (Bon) Schrot. is pre¬ 
ferred by the authors. 
LITERATURE CITED 
(1) Aderhold, R., and Ruhland, W. 
1905. ZUR KENNTNIS DER OBSTBAUM-SKLEROTINIEN. Arb. K. Biol. Anst. 
f. Land- u. Forstw. 4: 427-442, illus. 
(2) Bonorden, H. F. 
1851. HANDBUCH DER ALLGEMEINEN MYKOLOGIE. 336 p., illus. Stuttgart. 
(3) Conel, J. L. 
1914. A STUDY OF THE BROWN-ROT FUNGUS IN THE VICINITY OF CHAM¬ 
PAIGN and urbana, Illinois. Phytopathology 4: 93-101. 
(4) Ezekiel, W. N. 
1924. STRAINS OF THE BROWN-ROT FUNGUS, SCLEROTINIA AMERICANA. 
(Abstract) Phytopathology 14: 32. 
(5) Killian, K. 
1921. UBER DIE URSACHEN DER SPEZIALISIERUNG BEI DEN ASKOMYZETEN. 
I. DIE MONILIA CINEREA DER KIRSCHEN. Centbl. Bakt. (II) 53 1 
560-597, illus. 
