154 Ustilago. 



On Danthonia pilosa R. Br. 



Victoria— Near Dimboola, Nov., 1892 (Reader). Kiewa, Nov., 1902 

 (Robinson). Kircheim, Oct., 1898 (Eckert). Lake Albacutya, 

 Mallee, Oct., 1900 (C. French, jmi.). Rainbow, Oct., 1908. 

 Mallee, Nov., 1903 (Williamson Wallace). 

 Tasmania — Risdon, near Hobart, May, 1899 (Rodway). 

 On Danthonia sp. 



South Australia — Murray Bridge, Dec, 1892 (Tepper). 

 Dr. Ludwig has kindly sent me a portion of the original material which 

 is given as occurring on Stipa, but on comparing both the host and the fungus 

 with that found on Danthonia, it is seen to be the same, and that the host- 

 plant has been wrongly determined. 



In Dr. Cooke's Australian Handbook this species on Danthonia is given 

 as U. segetmn Bull. 



This species was first named by Dr. Ludwig in 1893 from specimens sent 

 by Mr. Tepper. Then Massee received a specimen from Rodway later and it 

 was named U .micros por a, but since the name was pre-occupied by Schroeter 

 and Henning in 1896, it was changed to U. exigua by Sydow. However, 

 the original name of Ludwig now stands. 



Spore formation. — Cross sections of the stem show the various tissues of 

 the host-plant, and the fibro-vascular bundles are penetrated by the myce- 

 lium. On the outside of the outer ring of bundles a continuous stroma or 

 compact mass of filaments is formed, and the projecting hyphae develop spores 

 in succession. The inner are colourless, but towards the outside they become 

 olivaceous and are held together at first by the remnants of the stroma. All 

 the hyphae arising from the stroma seem to became spore-bearing, and de- 

 tached portions of the outer tissues occur among them. 



CTermination of 1902 material was tried several times but did not succeed. 

 Spores collected in October 1908 were placed in a Petri-dish with water on 

 21st January, 1909. It was only after nine days that they began to germinate, 

 and produced occasionally a one-septate promycelium about 6 /j long. 



(Plates XIX., XXXVII.) 



Panicum. 

 9. Ustiiago confusa Mass. 



Massee, Grev. XX., p. 65 (1892). 

 Cooke, Handb. Austr. Fung., p. 32-1 (1892). 

 Sacc. Syll. XL, p. 230 (1895). 

 Sori in ovaries, soon naked, pulverulent, violet-black. 

 Spores clear-brown, with a tinge of violet by transmitted light, sub- 

 globose or irregularly angular, epispore about 1 /' thick, perfectly 

 smooth, 11-12 /( diam. 

 On Panicum paradoxum R. Br. = Chamaeraphis paradoxa Poii'. 



Victoria. 

 It was previously confounded with Ustilago destruens Schlecht, from 

 which it is distinct. 



Specimen not seen, and informed that there is no material available at 

 the Royal Gardens, Kew. Whether this species agrees with others recorded 

 on species of Panicum can only be settled when the smut is again discovered 

 on this host-plant. 



