OX CYPERACE.E 



245 



111. Puccinia silvatica Schrot. 



jEddium Taraxaci K. et S. Myk. Heft. i. 85. 



Puccinia silvatica Schrot. in Cohn, Beitr. iii. 68. Plowr. Ured. p. I 72. 



Sacc. Syll. vii. 627. Sydow, Monogr. i. 056. Fischer, Ured. 



Schweiz, p. 289, f. 211. 



Spermogones. In little clusters, yellowish. 



jEcidiospores. /Ecidia hypophyllous or amphigenous, on 

 roundish yellow or brown spots, in crowded 

 clusters 2—5 mm. wide, rarely solitary, occa- 

 sionally on the peduncle which they distort, 

 cup-shaped, with torn whitish revolute mar- 

 gin; spores nearly smooth, orange, 14 — 21 /x. 



[ Uredospores. Sori hypophyllous, scat- 

 tered, minute, oblong, brown; spores globose 

 to ovate, echinulate, brown, 20 — 27 x 15 — 



22yCA. 



Teleutospores. Sori hypophyllous, scat- 

 tered, minute, roundish or oblong, reaching 

 1 mm. in length, pulvinate, black ; spores cla- 

 vate, rounded and much thickened (up to 11 fi) 

 above, rarely conic-ally attenuated, gently con- 

 stricted, tapering below, smooth, pale-brown, 

 darker at the apex, 35 — 55 x 12 — 18 /a; pedicels 

 brownish, persistent, as much as 40 /x long.] 



iEcidia on Taraxacum officinale, June. 

 July. I have seen specimens from both 

 England and Ireland. Teleutospores on species of Garex. 

 (Fig. 189.) 



The question whether /'. silvatica occurs in Britain is still in the same 

 state as in Soppitt's time. The secidium agrees with the one assigned 

 to that species, but the teleutospores have not been found ; there is no 

 evidence that those found on Garex remota at Kew belonged to this species. 

 The distinction of this recidium from that belonging to P. variabilis lies 

 chiefly in the clustered peridia, which are situated on a thickened part of 

 the leaf, the peridium-cells are arranged in evident rows and the spores 

 form, according to Juel, longer chains. Fischer insists that the peridium 

 cells are thickest on the outer side, while those of P. variabilis are thickest 

 on the inner side : he maintains that this difference is characteristic of 



Fig. 189. P. sil- 

 vatica. iEcidia 

 on leaf of Tarax- 

 acum, from one 

 of Soppitt's spec- 

 imens, Saltaire. 



