176 ^CIDIACK^. 



M. compo sit arum. Mart. Solidago Cluster Cup. 



Spores, purplish, round, confluent. Peridia crowded, in 

 round patches. Spores round, patches. 

 On Solidago lanceolata. 



M. geranii. D. C. Cranesbill Cluster Cup. 



Peridia, in circular patches, with a bright red border. 



Spores, yellow, on the under surface of leaves. 



A beautiful object with a common lens. Common on our geranium 

 maculatum. 



i^. ranunculi. Schw. Crowsfoot Cluster Cup. 

 Peridia, small, scattered, 3'ellow. 

 Spores, also yellow. 



Common on ranunculus abortivus, which is quite numerous in our open 

 woods. 



>E. convallarise. Schw. Solomon Seal Cluster Cup. 



Peridia, in large patches, light yellow or nearly white. 

 Common on polygonatum. 



Genus IV. C^OMA. 



Spots becoming a powdery mass ; spores bright orange ; 

 spermogonia present. 



C. nitans. Schw. Common Blackberry Rust. 



Spores produced in vertical chains, spermogonia present. 



Spots, bright orange, sometimes covering the whole leaf. 



This parasite is so well known that it is barely necessary to give all the 

 microscopical characters. If you see a blackberry bush dusted over with 

 an orange dust during June and July it cannot be anything else but the 

 nitans, Schw. The vegetative part or mycelium permeates the cellular 

 portion of the leaf, sucking the life out of the plant. The spores are 

 very irritating ; so much so that I have had cases similar to hay fever 

 from inhalation. Common on our blackberry bushes. 



