ipo Tilletia. 



TILLETIA Tul. 



Sori in various parts of the host, usually in ovaries, generally pulveru- 

 lent, black or blackish-olive, often foetid, especially when moistened. 



Spores single, free, usually produced singly in the ends of fertile swollen 

 hyphae, which generally disappear almost completely through gelatinization, 

 of relatively large size. 



Germination by means of a short promycelium which bears a terminal 

 whorl of slender elongated conidia, and these often fuse in pairs, giving rise to 

 slender secondary conidia on germination. 



This genus differs mainly from Ustilago in the mode of germination of 

 the spores, and where this is not known, species are placed here provisionally 

 on account of the relatively larger size of the spores as compared with those 

 of Ustilago. 



Australian species, 6. 



53. Tilletia fusca Ell. and Ev. 



Ellis and Everhart, Journ. Myc. III., p. 55 (1887). 

 Sacc. Syll. YIL, p. 484 (1888). 



Sori in ovaries of each spikelet, oblong, 3 mm. long, showing as dark 

 bodies while still enclosed by the glumes and afterwards rupturing 

 to allow the escape of the spores. 



Spores reddish-brown to dark reddish-brown, globose to ovoid or 

 oblong, occasionally angular, with prominent regular reticulations ; 

 ridges showing at circumference as short blunt projections and en- 

 veloped bv a clear membrane probably gelatinous ; 23-25 /i diam. 

 or 23-26 x 18-20 ^/. 



Sterile cells hyaline, relatively thin-walled, globose to oblong, 

 generally smaller than the spores, 16-23 /it long. 



Occasionally small brown cells occur, smooth and only about 

 one-half the regular size, 10-13 fi. 



Both the colourless and coloured cells with smooth walls appear 

 to be immature spores, in the one case from not having attained the 

 full size ; in the other from not having developed the colouring 

 matter. 

 On Festuca hromoides L. — Silver grass. 



Victoria — Angustown, Dec, 1909, and March, 1910. 

 Although the Silver grass is widely distributed, I have not met with this 

 smut but in the one locality, where it is fairly common. The species only 

 occurs elsewhere in the United States of America, where it was first found on 

 Festuca. 



Germination. — Spores were placed on a slide in water which had been boiled, 

 on 7th December, and it was only after 17 days, on 24th December, that ger- 

 mination occurred in a few. The promycelium was elongated, biseptate, with 

 the vacuolated protoplasm transferred to the last segment. There were 

 usually a crown of seven conidia at the apex, each elongated, slender, sUghtly 

 curved and tapering, 66-72 /u long, and one pair were observed with a 

 transverse bar uniting them near the apex. 



(Plate LV.) 



