172 Cintraciia. 



Rynchospora. 



28. Cintractia leucoderma (Berk) P. Henn. 



P. Hennings, Hedw. XXXIV., p. 335 (1895). 

 Sacc. Syll. XIV., p. 420 (1899). 



Ustilago leucoderma Berk. Ann. Mag. Nat. Hist., 2 Ser. IX., 



p. 200 (1852). 

 Cintractia hrugiana Magn. Engl. .lahrl). XVII., p. 490 (1893). 



Sori surrounding flower stalks and stems, forming conspicuous elongated 

 bodies 3-30 mm. long, covered with a thick white crust of false 

 membrane, which gradually flakes away, leaving exposed the dense 

 black spore-mass. 



Sterile pale coloured thin-walled cells, scattered among the spores, 

 with margin rather irregular, due to gelatinization. 



Spores dark-brown, opaque, finely warted, globose to oblong 

 or angular, 13-16 }.i diam. occasionally 18 /t long. 



On Rynchospora aurea Vahl. 



Queensland — Bundaberg (Bailey). 



Queensland— Gatton, Sept., 1898 (Shelton, per Bailey''). 



The clear colourless spores produced inside gradually assume a smoky- 

 brown colour, then become darker towards the outside, and gradually fall 

 away as they mature. Although Berkeley describes the spore as smooth, 

 it is decidedly but finely warted. 



The thick white crust constituting the false membrane is very con- 

 spicuous and may gradually become detached and fall away piecemeal from 

 the host-plant. 



It is interesting to trace the history of this species from its earliest naming 

 by Berkeley, in 1852, until it was changed to Cintractia leucoderma by P. 

 Hennings in 1895. The original specimens were found on the sheaths of some 

 Sedge in the island of Saint Domingo, investing them with a white rugged 

 crust, and the spores were described by Berkeley as being perfectly smooth, 

 and 17 yn in diam. Next it was recorded on Cyperus rotundus L. (Nut-grass) 

 from Queensland by Dr. Cooke in 1892, and by F. M. Bailey in 1898. In 1893 

 Magnus determined a smut on Rynchospora gigantea Willd. as Cintractia 

 hrugiana, which P. Hennings showed in 1895 to be a synonym of this species 

 and therefore named it C. leucoderma. 



Finally in 1890, Saccardo determined a smut on Danthonia from Vic- 

 toria as JJ . leucoderma Berk., but on receiving a specimen of the same material 

 from Professor Ludwig, I found it to be the common species on this genus 

 of grasses, viz., JJ. readeri Syd. A specimen from the National Herbarium 

 labelled Ustilago leucoderma on Cyperus ? was forwarded to Miss Annie 

 Lorrain Smith of the British Museum. She determined it as Cintractia 

 leucoderma and was able to settle the identity of the host-plant as Rynchospora 

 aurea Vahl. The National Herbarium specimen said to be on Cyperus is 

 probably the same as the specimen from Bailey in which case the only host 

 is Rynchospora. 



Germination not described. 



( Plate XXXVII.) 



