Arthur: Cultures of Uredineae in 1910 21 



secure American material for cultures, and the ample success 

 when finally obtained is most gratifying. The American and 

 European collections of this interesting heteroecious rust appear 

 alike, and the present cultures show them to be identical. 



20. PucciNiA Absinthii DC, on a densely canescent species 

 of Artemisia, collected by Mr. E. Bethel, at Boulder, Colo., was 

 sown April 20, on A. dracunculoides, giving pycnia May 2, and 

 uredinia May 20, thus confirming the previous cultures of two 

 years ago.^^ 



21. Uromyces perigynius Halst., on Car ex intumescens Rudge, 

 collected by Professor W. P. Eraser, at Pictou, Nova Scotia, was 

 sown April 21, on Solidago nemoralis, again April 26, on 6'. cana- 

 densis, on May 13, on both nemoralis and ^9. canadensis, and 

 also on Aster paniculatus, and finally May 14, on Tissa canadensis 

 and Artemisia ludoviciana. Quite unexpectedly the only sowing 

 producing infection was on Aster, giving pycnia May 19, and 

 aecia May 31, both abundantly developed. 



Another collection apparently of the same rust, sent by Pro- 

 fessor Eraser, on Carex deflexa Hornem., was sown May 28, on 

 Solidago rugosa, S. canadensis and Aster Drummondii, with in- 

 fection only on the first, giving abundance of pycnia June 4, and 

 aecia June 16. 



A collection on Carex deflexa, collected by the writer at Isle au 

 Haut, Me., was sown May 13, on Solidago rugosa, S. nemoralis, 

 and Aster ericoides. On 5^. rugosa numerous pycnia appeared 

 May 20, and aecia May 31, but S. nemoralis remained free. The 

 Aster, moreover, showed pycnia May 24, and aecia June 6, but 

 they were not numerous and grew slowly. Solidago rugosa has 

 been taken with aecia in the telial vicinity, but Aster ericoides does 

 not grow there neither does any closely related species of Aster. 



Considerable study has been given to the species of Uromyces 

 on Carex since the initial and only culture^*^ in 1903. Some of the 

 conclusions may be briefly stated, without giving the steps by 

 which they were reached. We are doubtless dealing with races, 

 more or less well defined, parallel with the races of the Puccinia- 

 group, which latter goes under several names, two being given 



^ See Mycol. i : 243. 1909. 



^® See Jour. Myc. 10: 15. 1904. 



