98 A PLANT-DISEASE SURVEY IN TEXAS. 



MINT. 



Powdery mildew (Erysiphe galeopsidis DC). — Only the conidial 

 stage of this mildew was observed on mint (S tacky s drummondii 

 Benth.). 



Specimen collected : San Marcos, 947. 



MORNING-GLORY. 



Leaf -spot (Pkyllosticta ipomoeae Ell. and Kellerm.). — The leaves of 

 the morning-glory (Ipomoea 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). — White, 

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

 ciently abundant the foliage is apparently uniformlv 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 Nymphaea advena Soland are straw colored and several 

 centimeters in length, generally elongated in the direction of the 



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