14 - Sy nchytrium endobioticu m 
United States Department of Agriculture 
Bureau of Entomology and Plant Quarantine 
Apr. 1, 1940 
Foreign Plant Quarantines In-service Training Series. No. 6 
(No. 1 is an introductory and explanatory number.) 
Prepared by N. Rex Hunt 
N ame of Diseas e: Potato wart, potato canker or cancer, black scab, 
cauliflower, warty disease. 
Name of Pathogen : Synchytrium endobioticum (Schilb.) Perc. 
Syn. Chrysophlyctis endobiotica Schilb. 
Hosts : Hyoscyamu s niger , L ycopersicum esculentum , Nycandra physa - 
l odes , Solanum alatum , S. album , S. ch acoens e, S. commerso ni, 
S. dulcamara , S. j amesii , S. nodifloru m, S. tuberosum , S. 
vi llosisimu m, S. v illosum , and by inoculation D atura inermi s, 
D. mete l . Physalis francheti , Sc hiz ant hus pinnatus , Solanum 
atr opurpureum , S . marginatus , S . miniatum , S . miniatum rubricaule , 
S- miniatum vi ridicaule , S. niger , S. n igrum macrocarpum , S. 
nigrum chlorocarpum , S, r acemige.rum . 
Ducomet and Diehl (7) state that a study of tuberiferous 
species of Solanum showed that types susceptible to wart are 
present in all chromosome types, (1, 8, 15, 21) 
Part attacked : On potato the tubers are particularly susceptible, 
infection being through the eyes usually, but all underground 
parts of hosts are susceptible. Leaves and stems become in- 
fected also at times on potato at least. (13) 
Place of origin : South America. 
Country of first report : Hungary, 1896. (The part of Hungary in- 
volved later became part of Czechoslovakia) 
It is said the disease cannot be found now in the area 
from which Schilbersky first reported it. The disease ap- 
pears to have been in England (1, 4) at the time it was 
first reported. 
First report from the U . S.: Pennsylvania, Sept. 1918. 
Present distribution : Algeria, Austria, Belgium, Bolivia, Canada, 
Czechoslovakia, Danzig Free State, Denmark, England, Faroe 
Islands, Finland, France, Germany, Ireland, Japan, Malta 
(said to have been eradicated but see (16), Miquelon Island, 
Newfoundland, Peru, Poland (in an area formerly part of 
Germany), Portugal, Rumania, Scotland, Spain, St. Pierre, 
Sweden, Switzerland, Union of South Africa, United States, 
Wales. It has been reported from Russia, apparently in 
error. (19) 
