322 COLEOSPORIUM 
Since there are other so-called “species” of Peridermzum on the leaves 
of P. silvestris, which are morphologically not distinguishable from that 
belonging to this species, it is always advisable, when such a one is found, 
to look on the possible hosts in the neighbourhood for the corresponding 
Coleosporium. But the Percdermium found on the bark of Scots Pine is 
totally distinct, both morphologically and biologically, although Wolff and 
Plowright recorded them as identical. Plowright, however, failed to infect 
S. vulgaris by spores from “a specimen of dc. Pint on the bark of a 
young fir-branch” (i.e. pine-branch)—naturally enough ; and he also puts 
on record (/.c. p. 250) his frequent failures to infect the Groundsel with 
spores from ecidia (4c. Pind var. acicola) which seemed to him to be like 
those with which he succeeded. His consequent suspicion, that ‘there 
must be more than one species included under this name,” is now 
abundantly confirmed. He was experimenting, in these latter cases, with 
ecidia belonging to some of the species of Coleosporium mentioned in the 
following pages. 
In North America, C. Senecionis has been found on 8S. vulgaris, 
apparently in one locality only (Rhode Island), probably introduced from 
Europe ; the Peridermium was not observed. In that quarter of the globe 
there afte many indigenous species, biologically resembling ours, but 
mostly on different hosts, including one on a species of Orchidaceze. 
This fungus does not do much harm to the Pine, but in any case the 
removal of Senecio from the neighbourhood arrests the disease. The 
teleutospores germinate in the autumn in which they are produced. 
DIsTRIBUTION : Europe, North America (once). 
2. Coleosporium Tussilaginis Tul. 
Uredo Tussilaginis Schum. Pl, Sall. ii. 229. 
Coleosporium Tussilaginis “ Lév.” in Tul. Mém. Uréd. 1854, p. 136. 
Cooke, Handb. p. 520, f. 211; Micr. Fung. p. 217, pl. 8, f. 180—2. 
Fischer, Ured. Schweiz, p. 449. 
C. Sonchi Plowt. Ured. p. 250 p.p. Sace. Syll. vii. 752 p.p. 
aoe Plowrightii Kleb, Zeitschr. f. Pflanzenkr. ii, 258, pl. 5, 
. 6 
Aicidiospores. Acidia (P. Plowrighti’) like those of the 
allied species; spores oval or mostly round, delicately verrucose, 
20—380 x 15—24 pw. 
Uredospores. Sori hypophyllous, small, scattered or aggre- 
gate, orange; spores roundish, very densely verruculose, 23— 
28 x 17—21 yw; epispore rather thick. 
