200 ARTHUR-BISBY— TRANSLATION OF SCHWEINITZ'S 



Stage is \Yhite, and the name, Phragmidium alhidum, is often ap- 

 plied. Link's name of Cccoma ruborum belongs to another rust. 



2834. 24. C. U. Potentillarum, Lk. 87, Syn. Car. 461, frequent on Potentilla 



canadensis, [and in] Pennsylvania. 

 (461. 3. [Uredo] Alchemillse. I am certain it is the same as that 

 on Alchemilla. Here and there on the leaves of Potentilla cana- 

 densis, living through the winter.) 



Represented by a mounted packet containing loosely a bit of 

 stem and five leaves of the host mentioned. Three of the smaller 

 leaves show primary uredinia above, and two larger leaves show 

 secondary uredinia beneath, the sori being numerous. An empty 

 original packet is labelled " Caeoma (Ur) Potentillas canadens LvS 

 Sal & Beth." 



It was quite natural for Schweinitz to think this rust was a form 

 of Uredo Alchemillse, both from the gross appearance of the leaves 

 and of the sori on them, and to follow Link in placing it under the 

 inclusive name, C. Potentillarum. The rust is now known to be 

 wholly different, and is called Frommea obtusa (Strauss) Arth., or 

 more commonly, Phragmidiuin Potentillcu-canadensis Diet., or 

 Kiiehneola obtusa (Str.) Arth. 



2835. 25. C. U. Agrimonise L.v.S., usually wholly covering the lower surface 



of Agrimonia, wrongly [referred] to U. Rosse, Syn. Car. 462. 

 C. spots becoming yellowish. Sori minute, confluent, spores beauti- 

 fully reddish orange, finally losing their color. 

 (462. 4. [Uredo] Rosse. I do not doubt that it is the same as 

 occurs very frequently on Agrimonia Eupatoria in autumn ; 

 never on roses with us.) 



Represented by three terminal leaflets, mounted, each nearly 4 

 cm. long, and by fragments of three compound leaves in the original 

 packet, which is labelled " Cseoma (Ur) AgrimonicB LvS Salem." 

 All of the leaflets are abundantly covered with sori. 



The rust is the characteristic uredinial stage of Pucciniastrum 

 Agrimonies (Schw.) Tranz., which occurs in Europe and Asia, but 

 not so common there as in America. The host appears to be Agri- 

 monia parvi flora Soland. 



