PAPERS GIVING RUSTS OF NORTH AMERICA. 247 



All the fragments show very large sori, reaching 3 cm. long, 

 characteristic of the rust on Vernonia when occurring on the stems. 

 This is undoubtedly the same rust as the leaf form, recorded under 

 no. 2926, as P. Vernonice, a name still generally applied to this rust. 

 The leaf form has been grown by sowing spores from the large 

 stem sori. 



The asterisk before this number is a typographical error. 



*2g20. 16. P. Pycnanthemi, L.v.S., rather related to P. Clinopodii, frequent 

 on P. incanum, Bethlehem. 

 P. spots purple, minute, persistent. Sori small, fuscous. Spores 

 loose, long pedicelled. 



Represented by an empty packet, labelled on the inside " Cseoma 

 (Uredo) Labiatarum in Pycnanth glauci fol Beth," with Uredo 

 crossed out and " Puccinia " substituted, and on the outside " Puc- 

 cinia Pycnanthemi LvS in Pyc incano Beth." 



The host can be accepted as correctly named, and the rust as 

 identical with Puccinia Menthcu Pers. 



*2g2i. 17. P. compositarum, Lk. n. 19, common, Bethlehem, especially on 

 the stems and leaves of dead Cnicus or Cirsium (P. caulincola). 



Represented by an original packet containing six sections of 

 weathered stems about 5 cm. long, the largest being 5 mm. in diam- 

 eter, and all bearing telia. The packet is labelled " Puccinia caulin- 

 cola vere in caulib. Cnici altissimi," with " compositarum " after- 

 ward written in. 



The cobwebby hairs on these stems indicate that they are thistles, 

 and there is every reason to believe that they belong to Cirsium 

 altissimum (L.) Spreng. (Cnicus altissinius Willd.) as labelled by 

 Schweinitz. The rust agrees with Puccinia Cirsii Lasch. The ref- 

 erence to " P. caulincola " undoubtedly indicates the author's opinion 

 that his material might possibly be referred to the European Cccoma 

 caulincola Nees, which was originally found on stems of Centaurea 

 paniculata (Syst. Pilze, 16, 1816). By later authors the specific 

 name was transferred to Puccinia and applied to other forms. 



