n04 TWENTY-FIRST REPORT. 



Jackson, H. S. Carduaoeous specios of J'uccinia, I. Si)(>('ios oe(Mirring on the 

 tribe Vernonise. Botanical Gazette 65: 289-312. 1918. 



Arthur, J. C. North American rose rusts. Torreya 9: 21-28. Figs. 1-3. 

 1909. Phragmidium. 



Dietel, P. Ueber die Arten der Gattung Phra^niidium. Hedwigia 44: 112- 

 132, 330-346. PI. 4. 1905. 



Arthur, J. C. and Kern, F. D. North American species of Peridermium. 

 Bulletin Torrej^ Botanical Club 33: 403-438. 1906. 



North American Species of Peridermium on Pine. Mycologia 6: 109-138. 

 1914. 



Weir, James R. and Hubert, Ernest E. Observations on forest tree rusts- 

 Am. Journ. of Bot. 4: 327-335. Figs. 1-2. 1917. 

 Discussion of rusts of fir with other stages on ferns. 



Ludwig, C. A. Notes on some North American rusts with Caeoma-like sori. 

 Phytopathology 5: 273-281. 1915. 

 Gives keys for the determination of .such rusts. 



Rhoads, A. S., Hedgcock, G. G., Bethel, E. and Hartley, C. Host relation- 

 ships of the North American rusts other than Gymnosporangium, which 

 attack Conifers. Phytopathology 8: 309-352. 1918. 

 A very helpful paper for rusts on Conifers. 



Olive, E. W. and Whetzel, H. H. Endophyllum-like rusts of Porto Rico. 

 Am. Journ. of Bot. 4: 44-52. Pis. 1-3. 1917. 



Arthur, J. C. Relationship of the genus Kuehneola. Bulletin of the Torrey 

 Botanical Club 44:501-511. 1912. 



The Uredineae occurring upon Phragmites, Spa/tina, and Arundiuaria in 

 America. 

 Botanical Gazette 34: 1-20. Figs. I-4. 1902. 



Bisby, G. R. The Uredinales found upon the Onagraeeae. Am. Journ. 

 Bot. 3: 527-561. 1916. 



Holway, E. W. D. North American Salvia Rusis. Journal of Mycology 

 11:156-158. 1905. 



Mains, E. B. Species of M(dampsora occurring upon Euphorbia in North 

 America. 

 Phytopathology 7: 101-105. 1917. 



Rees, C. C. The rusts occurring on the genus Fritillaria. Am. Journ. 

 Bot. 4: 268-373. Figs. 1-3. 1917. 



Orton, C. R. North American Species of AUodus. Memoirs of the New 

 York Botanical Garden 6: 173-208. 1916. 



