Puccinia Com-positae. 153 



Chrysanthemum. 

 79. Puccinia chrysanthemi Roze. 



Roze, Bull. Soc. Myc. France, p. 92 (1900). 

 Sydow, Mon. Ured. L, p. 46 (1902), p. 854 (1904). 

 Sacc. Syll. XVL, p. 296 (1902). 



P. chrysanthemi chinensis P. Heim. Hedw. XL., p. (26) (1901). 



II. Uredosori on both surfaces of leaf, but mostly hypophyllous, 

 sparingly on stem, generally round, soon naked, powdery, scattered 

 or crowded, often confluent, sometimes arranged circularly, snuff 

 brown, average 1-1 J mm. diam., causing dirty -brown, indefinite 

 spots on upper surface of leaf, which gradually extend and 

 ultimately decay. 



Uredospores ellipsoid to obovoid, yellowish-brown to golden- 

 brown, echinulate, with 3 equatorial germ-pores on one face, 

 28-35 X 22-25 p (32 p long very common, occasionally reaching 

 a length of 45 p) ; pedicels hyaline, rarely persistent, stout, long, 

 up to 60 f.i. 



[III. Teleutosori on both surfaces of leaf, but chiefly on under surface, 

 prominent, roundish, pulvinate, solitary or confluent in groups, often 

 concentrically arranged, dark-brown to black, soon naked, compact. 

 Teleutospores at first sparingly intermixed with uredospores, 

 ellipsoid to pear-shaped or clavate, rounded or occasionally 

 truncate at apex, and thickened (up to 9 p), mostly rounded at base 

 or sometimes slightly attenuated, chestnut-brown, with strong, 

 finely punctulate epispore, 35-60 x 19-28 p; pedicel hyaline, stout, 

 persistent, 40-80 x 7-9 p.] 



[X. Mesospores rare, ellipsoid to clavate, similarly coloured to teletito- 

 spores, rounded and thickened at apex, finely ptinctulate, 28-46 x 

 22-25 p.] 



On cultivated Chrysanthemums (Chrysanthemum indicum L.). 



New South Wales Sydney Botanic Gardens, April, 1904 

 (Maiden). Sydney, May, 1904. 



This species has been assigned to P. hieracii by Massee , but Jacky 

 ', 2 , 3 has shown, by means of infection experiments, that it confines itself 

 to the one genus, and does not infect other Compositae. He has also experi- 

 mented with the Japanese chrysanthemum rust, P. chrysanthemi-chinensis P. 

 Henn., and proved it to be the same species as the other. 



Through the kindness of Professor Ideta, of the Agricultural College, 

 Osaka, Japan, I have received abundant material of the Japanese rust, both 

 in its uredo and teleuto stages, and am thereby enabled to compare it with 

 the rust occurring in Australia, as far as the uredo stage is concerned. The 

 uredospores are quite similar, having three equatorial germ-pores on one 

 face, and measuring 28-37 X 22-25 fj. Jacky 3 succeeded in infecting 

 C. indicum L., with material from C. sinense Sabine, and thus showed the 

 identity of the two rusts, although apparently in Europe and Australia it is 

 gradually losing the capacity to form teleutospores. Indeed, Miss Gibson ' 

 goes so far as to say that there is no necessity for resting-spores, for the 

 young shoots are above ground long before the old ones die away, and these 

 young shoots are taken as cuttings, so that there is no time when there are 

 no leaves upon which the rust can 'live. 



F 2 



