Puccinia Gramineae. 129 



Uredospores have been found all the year round and teleutospores from 

 August to December. Teleutospores are fairly plentiful in October, and 

 they are often three or even four celled. The three-celled forms have 

 either transverse septa, or the upper cell may be divided vertically or 

 slightly oblique. The four-celled is either produced by transverse septa, 

 the upper one being usually oblique, or the upper third may be divided 

 longitudinally. In these abnormal forms the length may reach 53 jj. and 

 the breadth 34 /j. at the apex. 



The genetic connexion between the aecidium on Coltsfoot (Tussilago 

 farfara) and this rust was first shown by Nielsen in 1876 and repeated by 

 Plowright in 1882, who found that the aecidiospores produced the uredo- 

 spores on POOL annua in ten to twelve days. But the Coltsfoot does not 

 exist in Australia, and, therefore, this rust can reproduce itself without the 

 intervention of aecidia. As might be anticipated the uredo stage carries 

 it over the winter, and, indeed, the fungus is most plentiful in our winter and 

 early spring months June, July, August, and September. Poa annua 

 as a rule dies away early in October, as soon as the warm weather comes on, 

 except in moist shady places. Lagerheim 1 , has found the spores on the 

 leaves after the melting of the snow. 



Darlucafilum Cast., commonly occurs. 



(Plate III., Fig. 22.) 



Sorghum. 



50. Puccinia purpurea Cooke. 



Cooke, Grev. V., p. 15 (1876). 

 Sydow, Mon. Ured. T., p. 803 (1888). 

 Sacc. Syll. VIL, p. 657 (1888). 

 Uredo sorghi Fckl. 



II. Uredosori amphigenous, seated on indeterminate, elongated and con- 

 fluent, bright red to purple spots, scattered or in small irregular 

 groups, covered by epidermis, and then splitting, yellowish-brown, 

 1-1 J mm. long. 



Uredospores ellipsoid, obovate to piriform, yellowish-brown, 

 roughly aculeate, with 3-4 germ-pores on one face, 28-34 X 

 20-25 ^/, average 31 x 21 /j. ; paraphyses intermixed. 



[III. Teleutosori on similar spots, mostly hypophyllous, oblong, elliptic, 

 or linear, always or long covered by epidermis, reddish-brown. 



Teleutospores ellipsoid, oblong or ovate-oblong, rounded at apex, 

 not or scarcely thickened, not or very slightly constricted at 

 septum, mostly rounded at base, smooth, bright brown, with very 

 thick epispore, 35-56 x 22-32 p. ; pedicel hyaline, persistent, 

 thick, up to 100 n long ; paraphyses present.] 



On leaves of Johnson Grass (Sorghum halepense Pers.) and Sugar-cane 

 {S. vulgar e Pers.). 



Queensland Gladfield (Gwyther), Nerang (Shirley), (Bailey H , 15 ). 



Only Uredospores have been met with here. 



In P. maydis the teleutospores are thickened at apex. Originally P. 

 sorghi Schwein. included rust on Zea and Sorghum, but it is now found 

 that the same rust does not occur on both, and Sydow, in his Monograph, 

 has wisely determined to reserve P. purpurea Cooke, for Sorghum and 

 P. maydis Bereng., for Zea. 



Darlucafilum Cast., is very common on uredosori. 



