98 A PLANT-DISEASE SUEVEY IN TEXAS. 



MINT. 



Powdery mildew {Erysiphe galeopsidis DC.)- — Only the conidial 

 stage of this mildew was observed on mint {Stachys drummondii 

 Benth.). 



Specimen collected : San Marcos, 947. 



MORNING-GLORY. 



Leaf -spot {Phyllosticta ipomoeae Ell. and Kellerm.). — The leaves of 

 the morning-glory {Ipomoca spp.) develop conspicuous brown spots 

 with a narrow dark margin. They are suborbicular and about 4 mm. 

 in diameter, becoming grayish with age. A few black pycnidia are 

 embedded in these areas. 



Specimens collected : Austin, 378 ; Seguin, 2316 ; Victoria, 2507. 



Rust {Puccinia cassipes B. and C). — Both the cluster cups and 

 teleutospores are abundantly present, often on the same leaves or 

 stems. 



Specimens collected : Austin, 192, 198, 330 ; San Marcos, 2105 ; Victoria, 2345, 

 2346; Flatonia, 2724. 



White-rust {Albugo ipomoeae-panduranae (S.) Swingle). — A^Tiite, 

 blisterlike elevations are formed on the leaves and stems. When suffi- 

 ciently abundant the foliage is apparently uniformly white. (PI. 

 XVIII, fig. 1.) 



This trouble is very generally distributed. The wild morning- 

 glories are common weeds in the cultivated fields and are affected by 

 the same white rust which attacks sweet potatoes. 



Specimens collected: Austin, 120. 420, 1305, 1306; New Braunfels, 1671; 

 Sabinal, 1979; Lockhart, 2071; Seguin, 2296; San Marcos. 2093; Georgetown, 

 2369; Round Rock, 2415; Elgin, 1879; Flatonia, 2725; Stockdale, 2623; Gonzales, 

 2693 ; San Antonio, 3167. 



MUSTARD. 



White-rust {Albugo Candida (P.) Rouss.). — The characteristic 

 white, blisterlike heaps of conidia occur on both surfaces of the 

 leaves of mustard {Brassica nigra (L.) Koch.), causing them to 

 become yellow and dry. 



Specimen collected : Austin, 3072. 



NYMPHAEA. 



Leaf-spot {Phyllosticta orontii Ell. and Martin).— The diseased 

 areas on Xymphaca advena Soland are straw colored and several 

 centimeters in length, generally elongated in the direction of the 



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