Til hi la. 



93 



In some seasons, such as 1898, in wliicli the sinnnier is comparatively 

 rainless, the smut-balls are harder and firmer than usual, so much so, that 

 they give great trouble in the mill, since they do not break up as is usually 

 the case. It is generally considered that the seed-case was dried up and 

 had no opportunity of softening in the absence of rain. On examining sec- 

 tions of such hardened grains, it was found that the spores of the smut were 

 not fully matured and that many of them were colourless. This would account 

 foj- the spores forming a dense mass and sticking together, because it is only 

 when they are fully mature that they fall away like powder. The drying up 

 would also, of course, tend to make the entire grain firm and hard. 



(Plates II., XLVIII.) 



Loliiim, Poa. 

 57. Tilletia striaeformis (Westd.) Oud. 



Oudemans, Bot. Zeit. XXXVI., p. 440 (1878). 

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



Tilletia de Baryana Fischer von Waldheim, Bull. -Soc. Imp. 



Nat. Moscow XL., p. 251 (1867). 

 Ustilago striaeformis (Westd.) Niessl, Hedw. XV., p. 1 (187G). 

 Ustilago 'poarum McAlp. Rov. Roc. Victoria, VII. (New Series), 



p. 220 (1894). 



Sori blackish to brownish-black, forming elongated streaks on the leaves, 

 leaf-sheaths and occasionally found in the ovaries, at first covered, 

 then free, becoming j)ulverulent. 



Spores globose to ellipsoid or even somewhat angular, olive-ljrown 

 prominently echinulate 10-13 fx diam. or 13-1(5 x 8-10 /». 

 On Lolium perenne L. — Rye-grass. 



Victoria — Creswick, Jan., 1892 (Robinson). Near Melbourne, Jan., 

 1901. Pakenham, Dec, 1900 (Robinson). Port Fairy, March, 

 1899 and Aug., 1900. 

 On Poa annua L. — Annual Meadow-grass. 



Victoria — Ardmona, Oct., 1893 (Robinson). 

 This species occurs on quite a number of grasses, but it has only hitherto 

 been found here on Rye-grass and Annual Meadow-grass. Every leaf of a 

 plant may be affected and growth is naturally prevented. It is only rarely 

 that in such diseased plants the ovaries are produced, and then they are com- 

 pletely destroyed by the smut. 



This species was named T. de Bari/ana by Fischer von Waldheim 3, but he 

 afterwards found, on examining the herbarium of M. Westendorp that the 

 Uredo striaeformis of that author was the same species, and accordingly that 

 specific name has been adopted. Niessl, however, considered it to be an 

 Ustilago, and Clinton'* still places this species under that geiuis, seeing that 

 the germination of the spores has not been observed and that their general 

 aspect is that of Ustilago. But as F. von Waldheim- has shown, the spores 

 are formed at the end of spore-bearing filaments as in Tilletia, although the 

 spore is surrounded by a gelatinous envelope up to the time of ripening. In 

 the perfectly mature spore, however, there is no trace of it, and until its posi- 

 tion is definitely settled by the germination of thespore it will be retained here. 



(Plate L.) 

 18.")S. II 



