322 COLEOSPORIUM 



Since there are other so-called " " of Peridermium on the leaves 



of /'. silvestris, which are morphologically not distinguishable from thai 

 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. Bui the Peridermium found on the bark of Scots Pine is 



lly distinct, both morphologically and biologically, although Wolff and 

 Plowrighl recorded them as identical. Plowright, however, failed to infect 

 S. vulgaris by spores from "a specimen of ./.'-•. Pini on the bark of a 

 young fir-branch" i.e. pine-branch) — naturally enough ; and he also puts 

 on record I.e. p. 250 his frequenl failures to infect the Groundsel with 

 spores from secidia ./-.'■. Pini var. acicola which seemed to him to be like 

 those with which he succeeded. Ili> consequent suspicion, thai "there 

 must be more than one species included under this name.'" is now 

 abundantly continued. He was experimenting, in these latter cases, with 

 secidia belonging to some of the species of Coleosporium mentioned in the 

 following pages. 



In North America, C. Senecionis has been found on S. vulgaris, 

 apparently in one locality only (Rhode Island . probably introduce! from 

 Europe ; the Peridermium was not observed. In that quarter of the globe 

 there are many indigenous species, biologically resembling ours, but 

 mostly <m different hosts, including one on a species of Orchidacese. 



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. 



I'l-'iJo Tussilaginis Schum. PI. Sail. ii. 229. 



Coleosporium Tussilaginis " Lev." in Tul. Mem. Ured. 1^54, p. 136. 



Cooke. Handb. p. 520, f. 211 ; Micr. Fung. p. 217. pi. 8, f. 180—2. 



Fischer, Ured. Sclrweiz, p. 1 lit. 

 C. Soue/ti Plowr. Ured. p. 250 p.p. Sacc. Syll. vii. 752 p.p. 

 Peridermium Plovmghtii Ivleb. Zeitschr. f. Pflanzenkr. ii. 258, pi. 5, 



f. 6. 



JEcidiospores. iEcidia (P. Plowrightii) like those of the 

 allied species; spores oval or mostly round, delicately verrucose, 

 20—30 x 15—24 ix. 



Uredospores. Sori hypophyllous, small, scattered or aggre- 

 gate, orange ; spores roundish, very densely verruculose, 23 — 

 28 x 17 — 21 p,: epispore rather thick. 



