202 



I'l ( < INI \ 



experimentally proved by De Bary andJacky. Bock (Centralbl. fiir Bakt. 

 •_'. x.\. 586) showed that what appeared to be identical with /'. Violae could 

 also !"• artificially produced on I', comma, V. Intra, I', tricolor; the 

 secidia formed small or Large crowded well-defined groups, and thereby 

 differed from those of /'. aegra which spread widely over the stems and 

 leaves of their hosts, mostly standing alone and not collected in groups. 

 In the latter, moreover, secidia and teleutospores can be found in July at 

 the same time (or even on the same leaf), which is not usually the case 

 with /'. Violae. This species can attack cultivated violets, but rarely does 

 much harm ; burning the infected plants is a sufficient remedy. 



Distribution : World-wide, except Australia. 



74. Puccinia aegra Grove. 



.Eciih'nm (l<'i>au{jcra>ix\ T \Y.e, Gard. Ghron. I s 7<'> pp. 



Cooke, Micr. Fung. p. 195 ; Grevillea, v. 57. 

 Puccinia argra Grove, Journ. Bot. xxi. (1883) p. 274. 



p. 158. Sacc. Syll. vii. 614. 

 P. depauperans Sydow, Monogr. i. 442 (1903). 



175, 361, 437. 



Plowr. Ured. 



Uredospores. 



JEcidiospores. ^Ecidia on all green parts of the host, 

 particularly on the stems, not in clusters, but spread pretty 

 uniformly over the whole surface, especially of the stems which 

 are swollen and distorted, cup-shaped, with a white torn revolute 

 margin; spores globose to ellipsoid, smooth, orange, 17 — 21 x 

 14— 16 fx. 



Sori amphigenous, without spots, irregularly 

 scattered or aggregated, occasionally 

 confluent, long covered by the lead- 

 coloured epidermis, cinnamon ; spores 

 globose to ellipsoid, delicately echinu- 

 late, brownish 20 — 28 /x diam. 



Teleutospores. Sori similar, but 

 darker; spores ellipsoid or ovoid, 

 rounded or gently attenuated above, 

 where it is slightly thickened or rather surmounted by a minute 

 subhyaline papilla, hardly constricted, usually rounded below, 

 very delicately punctate or quite smooth, brown, 22 — 34 x 16 — 

 20 ix ; pedicels hyaline, short ; a few mesospores are found. 



Fig. 150. P. argra. Teleuto- 

 spores and mesospore. 



