94 A PLANT-DISEASE SURVEY IN TEXAS. 



fades out into the green. The pycnidia are numerous, epiphyllous, 

 36 to 45 fi in diameter; the spores are oval or elliptical, 4 to 6 by 

 2.5 to 3 (x. 



Specimen collected: Seguiu, 2310 (type specimen). 



Rust (Puccinia cognata Syd.). — Punctiform telia and uredinia are 

 produced upon the under surface of the leaves. Common. 

 Specimens collected: Austin, rffe, 346, 361. 



DAYFLOWER. 



Rust (Uromyces spegazzinii (DeT.) Kern. nov. comb.). — Observed 

 in only one locality, where it was very abundant on the dayflower 



(C ommelina virginica L.). 

 Specimen collected: Austin, 232. 



DOCK. 



Dodder (Cuscuta indecora Choisy). — Observed on dock (Rumex 

 berlandieri Meisn.) in a low, moist field, where it had grown over 

 other plants. 



Specimen collected: San Antonio, 1776. 



EVENING PRIMROSE. 



Powdery mildew (Erysiphe polygoni DC.). — Found on the evening 

 primrose (OenotJiera laciniata Hill) in only a single locality. 

 Specimen collected: Austin, 1051. 



EUPHORBIA. 



Rust ( Vromyces euphorbias Cke. and Pk. ) . — The rust is very com- 

 mon on the euphorbias (Euphorbia spp.) of this section, forming on 

 the leaves very abundant brown, circular pustules. 



Specimens collected : San Antonio, 1397, 3174 ; Austin, 1420, 1908, 3102 ; Lock- 

 hart, 2077. 



FALSE DANDELION. 



Rust (Puccinia pyrrhopappi Syd.). — The sori are produced pro- 

 fusely on the stems, leaves, and involucres of the false dandelion 

 (Sitilias midticaulis (DC.) Greene). This rust was observed to be 

 exceedingly abundant in and about Austin, where it caused the death 

 of the plants. 



Specimens collected : Austin, 1073, 1264, 2948, 3061 ; Hempstead. 1515. 



FIRE WEED. 



Leaf -spot (Cercospora vernoniae Ell. and Kellerm.). — This fungus 

 on the fireweed (Vemonia spp.) produces irregular, rounded, or angu- 



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