■212 



PUCCINIA 



82. Puccinia Ribis 1 >< '. 



Puccinia Ribis 1><'. Flor. IV. ii. 221. Gard. Chron. 1894, xvi. L35. 

 Trans. Brit. Myc. Soc. i. 57. Sacc. Syll vii. 679. Sydow, 

 Mqnogr. i. 496. 



Teleutospores. Sori epiphyllous, orbicular, surrounded by a 



discoloured yellow zone, circulate 

 and often confluent, pulverulent, 



rich chestnut-brown; spores oval 

 or oblong, rounded above and be- 

 low, apex thickened slightly and 

 hooded, hardly constricted, verru- 

 culose or rather punctate, chest- 

 nut-brown, 20—30 x 15— 20 /a; 

 pedicels hyaline, thin, deciduous, 

 about as long as the spore; a few 

 mesospores intermixed. 



I )n leaves of Ribes rubrum. Very rare. Dallas Manse 

 ( tarden, Elginshire, July 16, 1894 (Rev. Dr Keith). (Fig. 159.) 



The pore of the lower cell is always towards the base, near the insertion 

 of the pedicel. Eriksson showed that the teleutospores do not germinate 

 until they have passed through the winter. He considers the form on 

 Ribes rubrum as biologically distinct from that on It. nigrum or It. 

 Grossularia. 



Distribution: Central and Northern Europe, North 



America. 



F.ig. 159. P. Ribis. Teleutospores 

 and mesospore. 



83. Puccinia Saxifragae Schlecht. 



Puccinia Saxifragae Schlecht. Flor. Berol. ii. 134. Plowr. Ured. 



p. 208. Sacc. Syll. vii. 678. Sydow, Monogr. i. 500. Fischer, 



Ured. Schweiz, p. 151, f. 117. 

 /'. Saxifragarum Cooke, Micr. Fung. p. 209 (non Handb. p. 506). 



Teleutospores. Sori generally hypophyllous, on discoloured 

 spots, round, scattered or aggregated and confluent and then 

 irregular, soon naked, pulverulent, dark-brown : spores ellipsoid 

 or oblong, rounded at both ends or slightly attenuated below, 

 slightly constricted, often surmounted by a rather large -pale 



