orton: north American species of allodus 177 



This intermingling of mycelia of both generations is not known 

 definitely to occur in any other species of Allodus and so can 

 hardly be regarded as typical. Whether this species forms 

 secondary aecia has not been proved. What little cultural data 

 is at hand indicates that secondary aecia may or may not 

 occur in the genus and the taxonomic studies bear out this 

 statement. 



The species in the genus appear to be quite variable in life 

 history. A. claytoniata has been cultured by Dr. F. D. Fromme 

 in the laboratory at Columbia University. His unpublished 

 results show that aeciospores from primary aecia, when sown 

 give rise to telia of the scattered type. The taxonomic studies 

 on this species corroborate his results. 



Bubak^ studied A. ambigua, a rust occurring in Galium Aparine 

 in Europe and North America. He found that primary aecia 

 were followed by secondary aecia. 



Treboux- has more recently checked up Bubak's studies on 

 A. ambigua and found them to be correct. These results are in 

 accordance with those of Dietel- who cultured Uromyces Behenis 

 (DC.) linger and Uromyces Scrophulariae (DC.) Fuckel, two species 

 to be referred to the genus Uromycopsis, which has the same life 

 cycle as Allodus. In both species in question he found that 

 secondary aecia followed primary aecia. 



Although the number of cultures are limited they indicate 

 two distinct life histories. In one case primary aeciospores give 

 rise to telia of the scattered type. In the other case primary 

 aecia are followed by secondary aecia which in turn give rise to 

 telia formed around the secondary aecia and from the same 

 mycelium, or telia of the scattered type may be formed but 

 whether these last arise from primary or secondary aeciospore 

 infection is not known. 



Other variations occur, such as evident perennial gametophytic 

 mycelium which appears to exist in A. consimilis, A. Douglasii, 

 A. Giliae, A. Chamaesarachae, A. intermixta, and A. Batesiana. 



Cultural studies must be made to determine the nature of the 



1 Bubak, Fr. O rezich, ktere cizopasi na nekterych Rubiaceich. Sitz.-ber. Bohm. 

 Ges. Wiss. 1898^8: 1-23. 1898. Reviewed in Zeitschr. Pfl.-Kr. 9: 116. 1899. 



2 Treboux, O. Ann. Myc. 10: 305. 1912. 



^ Dietel, P. Uber Rostpiize mit niederholter Aecidien-bildung. Flora 81: 394-404. 

 1895. 



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