MILDEWS, RUSTS AND SMUTS 
67 
and the promycelium spores give origin to the pycnidia 
and aecidium forms, thus commencing the cycle over again. 
Mesospores and amphispores, as supplementary spore- 
forms, have been previously described. 
KEY TO THE GENERA 
A. Telentospores \-celled. 
Teleutospores forming a small, powdery heap or sorus 
at maturity. .Spores with one germ-pore at the apex. 
Uromyces. 
Teleutospores and uredospores in the same sorus, emerging 
only through the stomata. Hemileia. 
Teleutospore sorus forming a small, flattened, crust-like 
patch . Melampsora. 
Teleutospores forming an erect, hair-like column. 
Cronariium. 
Teleutospores in chains, enclosed in a peridium. 
Endophyllum. 
Teleutospores colourless ; parasitic on ferns. Milesia. 
B. Teleutospores 2-celled. 
Teleutospore sorus foiming a small, powdery heap at 
maturity . Puccinia. 
Teleutospores forming subgelatinous outgrowths; on 
junipers. Gymnosporanghim. 
C. Teleutospores more than i-septate, all the septa parallel. 
Teleutospores cylindrical, septa varying from 3—7. 
Phragmidium. 
Teleutospores cylindrical, deeply notched at the septa, 
which vary from 8—15 in number. Xenodochus. 
Teleutospores forming extended crusts on swollen stems 
of cowberry. Calyptospora. 
Teleutospore sori flattish, crust-like ; promycelium only 
bearing one promycelium spore at its tip. 
Coleosporium. 
Teleutospore sorus enclosed in a peridium ; growing on 
Elymus . Rostrupia. 
D. Teleutospores g,-septate, septa radiating from the 
centre of the spore. 
Teleutospores 3-septate. Triphragmium. 
NOTES ON THE GENERA 
UROMYCES 
Aecidia, uredo- and teleutospore forms are often present. 
The aecidia or “ cluster-cup stage, as usual, appears 
