172 



Piiccinia Lcguminosac. 



On leaves of Plum (Primus domestica L.) and Nectarine. 



Victoria, New South Wales (Cobb 1 ), Queensland (Bailey 5 ) 

 (Tryon 1 ), South Australia, West Australia, and Tasmania 

 (Rod way 1 ). 



Common. November to June, the teleutospores being very common in 

 March on Prunus domestica. 



This rust is usually most prevalent towards the autumn, but in some 

 seasons it appears in the early summer. It not only destroys the foliage, 

 but may even attack the fruit, and in some seasons it actually ruptures the 

 bark, especially in rapidly growing nursery stock. When the rust occurs on 

 the fruit, uredospores may be produced both at the surface and in the pulp. 



There are said to be two kinds of uredospores by Dumee and Maire 1 , but 

 I 33 have shown that this is simply due to an error of interpretation, and 

 that they are always thickened at the apex when seen in their natural 

 position, and not obliquely. Teleutospores are comparatively rare on the 

 Apricot and Peach, less so on the Almond, and very common on the Plum. 

 In April, 1904, both stages of the rust were found on leaves of all the host- 

 plants. According to Prillieux 1 , teleutospores often appear alone, without 

 having being preceded by uredospores, but this has never been known to 

 occur in Australia. The arrangement of the teleutospores in the sorus is 

 worthy of note. With a magnifying glass the spores can be seen to be 

 arranged in minute clusters, and each cluster under the microscope is seen to 

 consist of a number of spores, the stalks of which have become agglutinated 

 together, and to the free end of each a spore is attached. (McAlpine 34 ). 



On the leaves of the Peach the sori are situated on yellow spots, which 

 are very prominent on the upper surface. There they often run together, 

 and have the appearance of yellow ochre. In the Apricot the spot is hardly 

 noticeable at first, but when held up to the light the indeterminate yellow 

 spots are seen clearly. The leaf soon turns yellow, and then the spots are 

 of a pale green. In the Plum the spots are very pale on the lower surface, 

 but on the upper surface the yellowish-green is very prominent. 



Tranzschel z has proved experimentally that the aecidial stage of the rust 

 on Almond occurs on Anemone coronaria L., and it has hitherto been known 

 as Aecidium punctatum Pers. 



Darluca filum Cast., is found on the uredosori. 



(Plate X., Figs. 83-86 ; Plate D., Figs. 19, 20.) 



LEGUMINOSAE. 



Zornia. 



103. Puccinia zorniae (Diet.) Me Alp. 



Uredozorniae Dietel, Hedwigia XXXVIII., p. 257 (1899). 



II. Uredosori on both surfaces of leaf, but most numerous on under, 



yellowish when young, then ruddy-brown, round to elliptic, 

 bullate, at first covered, then erumpent and surrounded by rup- 

 tured epidermis, gregarious and sometimes confluent. 



Uredospores old-gold colour, ellipsoid to occasionally obovoid, 

 finely echinulate, with two germ-pores on one face, 25-32 x 19-22^. 



III. Teleutosori as above, but dark-brown. 



Teleutospores intermixed with uredospores and similarly 

 coloured, oblong, smooth, deeply constricted at septum, two cells 

 about equal in size or lower sometimes a little longer, 32-44 x 

 20-24 p, average 36 x 21 p ; upper cell rounded and thickened 

 at apex (up to 6 /u), lower cell rounded at base ; pedicel hyaline, 

 persistent, about length of spore. 



