EYALOPSOEA 375 



(mostly four) cells; epispore thin, smooth, colourless; germ- 

 pore not prnvptihlo. 



On Polypodium Dryopteris. Uredospores, June — August; 

 teleutospores, May and June, on young leaves (Magnus). Rare. 

 (Fig. 27!).) 



Fischer, who records it also on P. Robertianum, states that the teleuto- 

 spores germinate in June. Arthur prefers to call the first kind of 

 uredospore the secidiospore ; this is possibly correct but, until something 

 is known about their development, it is premature to decide. According 

 to him, the secidia have no peridium, and the uredo-sori a very rudimentary 

 one, but I have repeatedly found both kinds of spores in the same sorus. 

 They appear perfectly smooth, when seen in water. 



Distribution : Europe, North America. 



2. Hyalopsora Polypodii Magn. 



Uredo linearis var. Polypodii Pers. Syn. p. 217. 



U. Filicum Desm. ; Cooke, Handb. p. 526; Micr. Fung. p. 215 p.p. 



White, Scot. Nat. 1877, iv. 27, pi. 2, f. 7. 

 U. Poly} "" Hi DC. Flor. fr. vi. 81. Plovvr. Ured. p. 256 p.p. Fungus 



Flor. Yorkshire, p. 204. Sacc. Syll. vii. 857 p.p. 

 Pucdniastrum Polypodii Dietel, in Hedwig. 1899, xxxviii. 260. 

 Hyalopsora Polypodii Magn. Ber. Deutsch. Bot. Gesell. 1901, xix. 582. 



Fischer, Ured. Schweiz, p. 474, f. 309. Arthur, N. Amer. Flor. 



vii. 112. Dietel, Annal. Mycol. 1911, ix. 530. 

 Uredinopsis Polypodii Liro, Uredin. Fennic. 1908, p. 496. 



Uredospores. Sori hypophyllous, minute, scattered, bullate, 

 golden-yellow, without a peridium, rup- 

 turing irregularly; spores more or less 

 globose or ellipsoid, of two kinds, (1) 

 thick-walled (2 — 3 //,), with very faint 

 warts, 26—38x18—29//, with 6—8 

 scattered germ-pores, (2) thin-walled 

 (1-- l\p), covered uniformly with faint 'u'reS'porS", on T^i!,- 



distant warts, 22 — 35x13 — 20 a, with pteris fragilis (Shrews- 



„ • i bury). 



lour equatorial germ-pores. 



Teleutospores. In the epidermal cells, often filling them 

 completely, showing as yellowish-brown spots on the under side 

 of the leaf, densely crowded, divided into 2 — 4 cells, each about 

 14 — 18 /z in diam., single cells subglobose ; epispore thin, 

 colourless; germ-pore perceptible at the upper end. 



