TWO NEW GRASS SMUTS. 201 



TWO NEW GRASS SMUTS. 



By Ewen MacKinnon, b.Sc, 

 Assistant Microbiologist, Government Bureau of Microbiology. 



With Plates X-XIIL 



[Read before the Royal Society of N. 8. Wales, December 4, 1912.] 



The following smuts are described in the present paper : 



1. Sorosporium panici on Panicum flavidum (Retz.) 



2. Ustilago panici-gracilis on Panicum gracile (R.Br.) 



Serial sections have been made through the inflorescences 

 and in connection with the work I have to thank Mr. G. 

 Grant for the photographic work, and Mr. W. A. Birming- 

 ham for the drawings of the germinations. 



The type specimens will be presented to the National 

 Herbarium at the Botanic Gardens and co-types will be 

 retained at the Government Bureau of Microbiology. 



1. Sorosporium panici, McK. Panicum. 



Sori in the spikelets, confined within the glumes and 

 converting the ovaries into black spore masses, the entire 

 inflorescence being powdered ; a central core of plant tissue 

 and an outer membrane enclosing the spore masses. Spore 

 balls rather few except in sections. Variable, common 

 size 50>, some measuring up to 100 x 60/x. Spores olivace- 

 ous or yellowish-brown. Epispore distinctly yet finely 

 e^hinulate. Variable in size and shape — globose to elliptical 

 often irregular and somewhat angular. Common size 10 - 

 12/x diam., but varying 10 x 12, 10 x 13*6, 10*2 x 14*3, 

 8*2 x 14*3, 7 x 15. 



On (?) Panicum flavidum, (Retz.), Nyngan Experiment 

 Farm, E. MacKinnon, February 1911. 



