ON COMPOSITE 153 
purplish spots, scattered, minute, punctiform, soon naked, 
brown; spores few, globose to ovate, echinulate, brown, 22— 
32 x 19—26 w, with two germ-pores. 
Teleutospores. Sori similar, but darker; spores ellipsoid to 
oblong, rounded at both ends, not thickened above, not con- 
se ON 
Fig. 105. P. variabilis, Hicidia, on leaf of Taraxacum, and teleutospore. 
stricted, delicately verruculose, brown, 28—40 x 18—25 pw; 
epispore thin; pedicels hyaline, about as long as the spore, but 
deciduous. 
On Turaxacum officinale and its variety palustre. July— 
October. Not common. (Fig. 105.) 
Plowright and Soppitt both proved, vy laying leaves affected with the 
ecidium of this species on healthy plants of Taraxacum, that the uredo- 
and teleutospores were produced in about fourteen days. In July the 
three spore-forms may be found on the same leaf. 
There are two forms of ecidium found upon Taraxacum ; one, Aeidium 
Grevillei Grove (=4. Taraxaci Grev. non K. et S.), spreads pretty 
uniformly over the whole leaf in “numerous little clusters with single ones 
scattered between them,” as Greville describes it (Flor. Edin. p. 444)—the 
other, @. Tarazaci K. et &., forms large round clusters, and belongs to 
P. silvatica, Fischer points out that the two ecidia differ in the form of 
their peridium cells, those of P. variabilis having the membrane thickened 
on the znner side, while those of P. silvatica have the outer wall most 
strongly thickened. He states, furthermore, that it will be found that 
this difference is characteristic in general of autcecious and hetercecious 
species respectively. It is not, however, universally so, e.g. the ecidium 
of P. albescens has the outer wall much more strongly thickened, although 
it is autcecious. 
Greville figures the teleutospores of his species (Scot. Crypt. Flor. pl]. 75) 
as having either one or both of the cells sometimes divided by a vertical 
septum. 
DistTRIBUTION: Switzerland, Sweden. 
