THE FUNGI WHICH CAUSE PLANT DISEASE 



377 



Fio. »73> 



-Cross-section of aecia of P. asparagi. 

 After Smith. 



P. bullata (Pers.) Schr. is a brachy-puccinia which is autoecious 

 on celery, parsley, dill and other Timbellifers. 



P. apn (Wallr.) Gda. abo occurs in its uredinial and telial stages 

 on celery .- 



P. castagnei Thiim is recorded for celery in France. 



P. allii (D. C.) Rud. is a hemi-type on cultivated onions. 



P. porri Sow. is an autoecious rust which is sometimes- de- 

 structive to onions in 

 Europe. 



P. endiviae Pass.^^^ 

 occurs on- endive in 

 Italy and America. 



P. phragmitis 

 Schum.2«-2« 



I (=^. rubelliun). 

 Peridia oh circular 

 red spots 0.5-1.5'cm. 

 in diameter, shallow, 

 edges white, torn. Spores white, subglobose, echinulate, 15-16 m 

 in diameter. 



II. Uredinia rather large, dark brown, elliptical, pulverulent, 

 without paraphyses. Spores ovate or elliptical, echinulate, brown, 

 25-35 X 15-23 /i. 



III. Telia large, long, sooty black, thick, often confluent. 

 Spores elliptical, roimded at both ends, markedly constricted in 

 the middle, dark blackish-brown, smooth, 45-65 x 16-25 n. Pedi- 

 cels very long, 150-200 x 5-8 n, yellowish, filmly attached. 



Heteroecious; I on Rumex and rhubarb, II and III on Phrag- 

 mitis. Found only rarely in America,^^'" ^** except in the middle 

 west. 



P. cyan! (Schl.) Pass, is on cultivated Centaurea. 



P. tragopogonis (Pers.) Cda. 



I. jEcia on the whole plant — leaves, stems, bracts, receptacles 

 — shortly cylindrical, at first mammseform, peridia with whitish, 

 torn edges. Spores rounded, verrucose, orange-yellow, 18-27 n, 

 sometimes as much as 35 m long. Mycelium diffused throughout 

 the host-plant. 



III. Telia brown, few, small, scattered, elliptical or elongate. 



