MKLAMPSORACE/E 337 



hybrids. Klebahn is the author who has chiefly studied the 

 group, and the following account of the known or supposed 

 British species on Sali.v is mainly founded upon his work. 



The artificial key to the species, here given, is based upon 

 that of Fischer, but must be taken with a little reservation 

 since, as is now known, the life-histories of such hetercecious 

 forms require to be worked out for each country separately. 



HETERCECIOUS. 



A. Teleutospores on Salix. 



a. Uredospores oblong, smooth at upper end. Coeoma on Allium. 



1. Teleutospores subepidermal. M. Allii-Salicis-albae. 



2. Teleutospores subcuticular. M. Allii-fragilis. 



b. Uredospores roundish, without smooth spot. 



1. Teleutospores subcuticular, strongly thickened above, with a 



conspicuous germ-pore. Cseoma on Larix. 



M. Larici-Caprearum. 



2. Teleutospores not strongly thickened above, without an evident 



germ-pore. 



(1) Teleutospores subepidermal. 



Cseoma on Larix. M. Larici-epitea. 



,, on Orchidaceoe. M. Orclddi-repentis. 



,, on Euonymus. M. Euonymi-Caprearum. 



„ on Ribes. M. Ribesii-purpureae. 



(2) Teleutospores subcuticular. M. Ribesii-viminalis. 



B. Teleutospores on Populus. 



a. Uredospores elongated, smooth above. Teleutospores on P. 



nigra, P. balsamifera. 



1. Caeoma on Larix. Teleutospores epiphyllous. 



M. Larici-populina. 



2. Cseoma on Allium. Teleutospores hypophyllous. 



M. Allii-poptdina. 



b. Uredospores roundisb, not smooth above. Teleutospores on 



P. alba, P. tremula. 



1. Ca3oma on Larix. M. Larici-tremulae. 



2. „ on Pinus. M. pinitorqua. 



3. „ on Mercurialis. M. Rostrupii. 



AUTCECTOUS. 



Teleutospores not on Salicaceae. 



M. Hypericorum, M. Lini, M. Euphorbiae, M. vernalis. 



G. u. 22 



