514 NOTE ON POLYPORIS LUCIDUS LEVSS. 



liable to infection when a favourable opportunity otters itself. 

 All logs or trees alTected with this fungus should be imme- 

 diately burned, and destruction of all sporophores made certain. 

 The instance cited where the fungus was breaking through a 

 concrete floor is definite evidence that the mycelium of the 

 fiuigus not only remains alive for a considerable time after the 

 death of its host, but that it is capable of forming fructifications 

 afresh should the first be removed. The destruction of all wood 

 harbouring- the fungus is thus essential. 



From information thus far to hand it would appear that the 

 fiuigus is not as yet of great economic importance, though con- 

 sidering the different hosts it is capable of attacking and its 

 a])i)arent frequent occurrence in various parts of the Union, it 

 should not be treated too lightly. It is common on Acacia sp.. 

 and Mr. T. R. Sim once collected the sessile form of Polyponis 

 scssilis (Plate 14a) on a living Acacia niollissima, our cultivated 

 wattle. Proper drainage accompanied by good forest sanitati<:)n 

 would go a long way towards i)reventing this fungus from ever 

 causing very serious trouble. 



SUMMAR^'. 



The paper deals with Polyponis Iiicidiis Leyss, a funs^us 

 very common on native Acacia, and its action on the wood of 

 the willow is recorded. 



The death of a large number of Acacia trees an)und Pre- 

 tria is attributed to this fungus, and the fact that it has been 

 found on Acacia inollissiiiia, our cultivated wattle, adds to its 

 imi>ortance. 



The action of the fungus on the woo'd of the willow is 

 described as one of digestion, which proceeds slowl\- and 

 gradually. 



Tlie fungus is held to Ije a facitltatic'C parasite, thouiiii there 

 is no doul)t that it is ca])al)le of attacking, and causing the death 

 of living trees. 



Methods of control should aim at the destruction of the 

 s])oroi)hores and of all material harbouring the myceliimi of the 

 fungus. This is essential, since the mycelium remains active and 

 retains its i)ower of fruiting for years after the host plant is 

 dead. With i)roper attention and care the fungus should never 

 become serious. 



X.B. — Material, either of this fungus or of other Poly- 

 pi raceme, will always be welcome, if sent to the autlior at the 

 Xatal Herbarium. Berea, Dtu-l)an. 



I'Lxi'LANATlON OF ILLUSTRATION'S. 



Plate I-'. .sporoi)hores of P. liicidits from an acacia tree. 



IMatc 13. S];orophores from stem and roots oi a li\ing willow 

 tree. 



Plate I4(/. .Sporoi)hori's fi-oni the sessile form Polyponis scs- 

 silis from !i\ini'' ./."(n/'j iiiollissiiita tree. 



