Parasitic Fungi of Illinois. 239 



tt. convallariae, Schum. 



Hypophyllous. Spots distinct, or more or less confluent, 

 lemon-yellow, scarcely thickened; aecidia loosely clustered, ir- 

 regular or subcircinate, short-cylindrical, recurved border nar- 

 row and abruptly turned; spores subglobose or oval, sometimes 

 angular, epispore thick, conspicuously tuberculate, 21-24 by 

 24-30 jt; spermagonia numerous, scattered over the central 

 area of the spot on both surfaces, dark reddish brown. 



On Smilacina: McLean, May 26, 4797. S. stellata: Mc- 

 Lean, June 1, 4885; LaSalle, June 19, 5224. S. racemosa : 

 McLean, May 31, 4861, 4862. 



RCBSTBLIA, REBENT. 



Spoaes one-celled, in chains or vertical rows, without pedi- 

 cels; sorus enclosed in an elongated, usually tapering, pseudo- 

 peridium, which protrudes far through the ruptured epidermis 

 of the host, and which becomes deeply split and fringed; with 



spermagonia. On species of Pomece. 



i 



JEcidia usually hypophyllous, lower part sunk in the swollen tissues 

 of the leaves, forming above cylindrical, conical, or oblong projections, 

 which are often split and fringed in the upper part, peridium composed 

 of large colorless cells, spores brownish or orange-colored, subglobose 

 when mature, formed in moniliform rows. Spermagonia punctiform, 

 forming minute dark-colored pustules in discolored spots on the upper 

 surface of the leaves. Mycelium infesting the leaves and stems of differ- 

 ent Pomese. Farlow, Gymnosporangia of the U. S. p. 24. 



The forms included here are now supposed to be (like those 

 Qi^EcMium) mere stages of development of other teleutospor- 

 ous species, and perhaps all belong to Gymnosporangium. The 

 genetic connection of the forms placed in these two genera was 

 first shown by Oersted, of Denmark, in 1865, who satified him- 

 self, by artificially sowing the spores, of the relationship exist- 

 ing. His conclusions have since been confirmed by DeBary in 

 Germany, Cornu in France, and Cramer in Switzerland; but 

 nothing conclusive has been ascertained in our country save 

 from the effects in nature of the proximity of the different hosts 

 and their parasites. Professor Farlow's artificial cultures (The 

 Gymnosporangia of the United States, p. 32, etc.) gave not only 



