290 



I'llltACMIDIC.M 



character, as well as the rigid middle lamina and the position 

 nf the germ-pores, distinguishes the genus from all the neigh- 

 bouring <>nes. 



1. Phragmidium Fragariastri Schrot. 



/'t/,;'i,,/'<i Fragariastri !)•'. Flor. fr. vi. 55. 



Phragmidiv/m obtusum Link, Sp. PL ii. 84 p.p. Cooke, Handb. 



p. 491 ; Micr. Fung. p. 201 (as obtusatum). 

 I'. Fragariastri Schrot. Flor. Schles. iii. 351. Plowr. Ured. p. 220. 



Fischer, Ured. Schweiz, p. 412, f. 287. Sacc. Syll. vii. 74^. 

 Sydow, Moiiogr. iii. 101, f. 45. 



Spermogones. In little clusters, honey-coloured. 

 jEcidiospores. Caeomata mostly hypophyllous or on the 



veins and petioles, irregular, 

 scattered, often confluent and 

 large, bright-orange, surrounded 

 by clavate paraphyses; spores 

 densely verruculose, orange- 

 yellow, 17—28 x 14—21 p. 



Uredospores. Sori hypo- 

 phyllous, scattered, roundish, 

 soon naked, surrounded by and 

 mixed with hyaline, thin-walled 

 capitate paraphyses ; spores 

 roundish, densely verruculose, 

 orange-yellow, 18 — 24 ji, 



Teleutuspores. Sori hypo- 

 phyllous, scattered, minute, roundish, pulverulent, brown; spores 

 cylindrical or rarely somewhat clavate, of 2 — 5 (mostly four) 

 cells, rounded at both ends, sometimes slightly thickened and 

 paler at the summit but never papillate, faintly constricted, 

 rather pale-brown, 45 — 70 x 22 — 28 p, sometimes with a few 

 delicate warts which are more abundant towards the apex, but 

 generally quite smooth ; usually three germ-pores to each cell ; 

 pedicels colourless, 14 — 21 jj, long. 



On Potentilla Fragariastrum (= P. sterilis), and possibly 

 on other species of the genus, but never on Fragaria vesca. 

 March — October. Very common. (Fig- 219.) 



Fig. 219. Ph. Fragariastri. Uredo- 

 spore, paraphvsis, and teleutospore ; 

 a, a teleutosj^ore boiled in lactic 

 acid. 



