New York Agricultural Experiment Station, 127 



Teleutospm'e stage. — The last stage is frequently called tlie 

 " black " rust and " winter " stage. To the unaided eye there is 

 no difference except in color, between this and the second stage. 

 Close examination will show that tlie rifts are filled with dark 

 brown spores whicli do not rub off and scatter as easily as the 

 red rust spores. These winter spores are two-celled, are larger, 

 and have thicker cell walls than those of the red rust (see Fig. 

 3, t, Plate XI). They are always formed whenever the vitaMty 

 of the asparagus plant is reduced or its growth checked, no mat- 

 ter what the season of the year, whether early June or late 

 October. According to Dr. Halsted^ all three stages can occur 

 at once on the same plant. It is supposed that these spores 

 do not germinate until the following spring, at which time, if 

 they succeed in getting a foothold on a young asparagus plant, 

 they soon produce the first stage. 



It is not known that it is absolutely necessary for the rust to 

 pass through the three different forms named each year, or 

 through any two of them. The last two forms may occur in the 

 same rift or sorus, being produced by the same vegetative por- 

 tion, or mycelial thread, of the fungus (see Fig. 2, Plate XI); 

 possibly all the forms may be produced in the same way. All 

 three forms certainly occur in this State: the first is found prin- 

 cipally during the month of June; the second occurs during the 

 latter part of June, and throughout the months of July, August, 

 September and October; the third follows the second as soon 

 as the asparagus commences to lose its vitality or begins to 

 mature. 



•Bui. Torrey Bot. Club, 24:509, 18d7. 



