294 PHRAGMIDIUM 
On Rosa canina, R. spinosissima, and many kinds of culti- 
Fig. 222. Ph. disciflorum. a, 
secidiospore, on cultivated Rose ; 
b, uredospore, and c, paraphyses, 
on Dog Rose; d, a small teleuto- 
spore, on the same; e, a teleuto- 
spore, on Burnet Rose; all x 600. 
vated roses. Very common. Ce- 
oma-spores in May and June; 
teleutospores, August—October. 
(Fig. 222.) 
The teleutospores can germinate in 
spring, and produce the ceoma (Jacky), 
but they germinate with difficulty 
(Miiller); the parasite is propagated 
chiefly by the mycelium of the czoma- 
stage, which passes the winter in the 
branches and in spring bursts out into 
wide-spreading spore-beds. These at- 
tack and destroy the buds ; afterwards 
the uredo- and teleutospores appear on 
the leaves, with localised mycelium. The 
infested branches are often swollen and 
deformed. To keep the disease under 
control, all teleutospore-bearing leaves 
and the branches which are permeated 
by the mycelium should be collected 
and burnt, and the plant may be 
sprayed, during the winter, with copper 
sulphate solution. 
It is noteworthy that this fungus 
occurs in North America only on cul- 
tivated roses; the indigenous Rose- 
Phragmidia are all different species. It has been introduced, probably by, 
cuttings, also into Australia and other parts of the world. 
DIstTRIBUTION: Europe, Asia Minor, Persia, Africa, North 
America, South America, Australia. 
5. Phragmidium fusiforme Schriter. 
Uredo pinguis var. Rosae-alpinae DC. Flor. fr, ii. 235. 
P. fusiforme Schrét. Rostpilze Schles. p. 24. Fischer, Ured. Schweiz, 
p. 404, f. 283. Sacc. Syll. vii. 747. Sydow, Monogr. iii. 121. 
Phragmidium Rosae-alpinae Wint. Pilze, p. 227. Plowr. Ured. p. 226. 
Aicidiospores. Sori on the petioles, nerves and fruits, 
similar to those of P. disciflorum, but not so extensive; on 
the leaves, punctiform and surrounded by hyaline clavate para- 
physes ; spores echinulate, 17—30 x 15—20 p. 
