ALBUGO PORTULACLEoR A. CANDIDA. 



THALLOPHYTES; FUNGI J PHYCOMYCETES. 



PRELIMINARY. 



THESE are very common parasitic Fungi. A. Candida 

 forms white patches on the surface of the leaves, stems, 

 and flowers of many cruciferous plants, such as various 

 species of Capsella, Sisymbrium, Lepidium, Nasturtium, 

 Sinapis, and Raphanus. It is especially abundant 

 upon Capsella, or "shepherd's-purse," from early spring 

 until late in the fall, whitening and distorting the stems, 

 leaves, and flowers. Yet, notwithstanding its luxuriant 

 growth, the sexual condition with resting spores is not 

 abundant within the tissues of this plant, but is produced 

 in great luxuriance inside the flowers and flowering 

 branches of radish (Raplianus), causing them to become 

 enormously enlarged, sometimes becoming even two to 

 five centimeters (one or two inches) across. 



A. Portulaca, found upon the leaves of purslane or 

 " pusley " (Portulaca oleracea), serves equally well for 

 this study, sex-organs being much more readily found 

 in it than in A. Candida. A. Bliti is very common on 

 the leaves of the common pigweed (Amaranlus retro- 

 flexus). 



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