PAPERS OX BIOLOGY AND AGRICULTURE 137 



This caiikei" is common in the northeastern states, 

 and is reported as especially destructive in Pennsylvania 

 where it occurs on the white, red, yellow and chestnut 

 oak and on the American chestnut. 



The canker caused by the fungus resembles that of 

 the European apple-tree canker. They are oval to ellip- 

 tical in outline with concentric folds about the slightly 

 sunken central area. On the surface of the cankers are 

 numerous small black pustules, the fruiting bodies of 

 the fungnis. 



KASPBERRY . 



Dodder {Cuscufa gronovii. "Willd.) Specimens of red 

 raspberry canes encircled by dodder were received from 

 S. I. Talbot of DeKalb. He wrote that this started on a 

 single bush in 1920 and had spread to six or eight since. 

 He stated that it was evidently sapping the life out of 

 the plants. The species of dodder was kindly determined 

 by Prof. T. S. Yuncker. Clinton reports dodder as oc- 

 curring on raspberrv in Connecticut. (Plant Dis. Bui. 

 Suppl. 14:101,1921.)" 



Since this species of Dodder is very common and oc- 

 curs on a large number of hosts it may easily be intro- 

 duced into berry patches. For this reason dodder grow- 

 ing on wild plants in the neighborhood of berry patches 

 should be destroyed. 



CALENDULA 



{Calendula officinale) 



Rust (Puccinia recedens Sydow). The calendula has 

 become a popular annual flower for the home flower 

 garden and is extensively grown in greenhouses for cut 

 flowers during the winter. Therefore, any disease which 

 threatens this plant is of considerable economic import- 

 ance. 



In the summer of 1920 a rust was observed on a num- 

 ber of these plants gro^\Ti in a home garden at Urbana. 

 Specimens were sent to Dr. H. S. Jackson of Purdue 

 University who identified the rust as Puccinia recedens 

 Sacc. He stated that it had never been reported on this 



