MELAMPSORACEA 337 
hybrids. Klebahn is the author who has chiefly studied the 
group, and the following account of the known or supposed 
British species on Salix 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. 
HETERGCIOUS. 
A. Teleutospores on Salix. 
a. Uredospores oblong, smooth at upper end. Czeoma on Allium. 
1. Teleutospores subepidermal. M. Allit-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. Coma on Larix. 
M. Larici-Caprearum. 
2. Teleutospores not strongly thickened above, without an evident 
germ-pore. 
(1) Teleutospores subepidermal. 
Ceoma on Larix. M. Larici-epitea. 
» on Orchidacee. M. Orchidi-repentis. 
» on Huonymus. M. Euonymi-Caprearum. 
» on R&ebes. M. Ribesti-purpureae. 
(2) Teleutospores subcuticular. M. Ribesti-viminalis. 
B. Teleutospores on Populus. 
a. Uredospores elongated, smooth above. Teleutospores on P. 
nigra, P. balsamifera. 
1. Cexoma on Larix. Teleutospores epiphyllous. 
M. Lariei-populina. 
2. Coma on Allium. Teleutospores hypophyllous. 
, M. Allit-populina. 
b. Uredospores roundish, not smooth above. Teleutospores on 
P. alba, P. tremula. 
1. Ceoma on Larix. M. Lariet-trenvutae. 
2. » on Pinus. AM. pinitorqua. 
3. » on Mercurialis. M. Rostrupit. 
AUTCECIOUS. 
Teleutospores not on Salicacee. 
M. Hypericorum, M. Lint, M. Euphorbiae, M. vernalis. 
G. Ue 22 
