6 4 
This is I <think, very doubtful. Trees shown to me as Daru in 
Sumatra were certainly not of this species. Probably more than 
one plant is the source of the timbers known as Daru in the trade. 
Most of it now I believe, comes from Sumatra. 
H. N. R. 
A FUNGUS ATTACKING ROOTS OF 
PARA RUBBER. 
From two Estates I have received rubber stems attacked with a 
subterranean fungus which does not appear to be Fomes semitostus. 
The trees are all young about 2 inches through. The roots are all 
encrusted with a white mycelium and dead, and the collar of the 
tree is also dead. One planter from Borneo writes that " If left alone 
the trees are absolutely dead within three weeks of the first appear- 
ance of the disease. They rot at the roots and in the green wood. 
The inside of the stem becomes discoloured and the tree falls. 
From 70 to 8oof the trees fteve died. They were not growing in a 
batch but are scattered about amongst the healthy trees.” The 
other planter sends somewhat similar information from Perak. The 
disease appears sporadically there also “The trees were growing” he 
writes “most luxuriantly on a new field, 8,000 of them, yet here and 
there wide apart about a dozen died. ” The trees are I gather about 
16 months old. 
It is impossible as yet to guess that fungus is the aggressor, as 
there are no sporophores yet. The stumps are put in a damp spot 
to see if the fungus will fruit. It is doubtless I think, one of the 
Polyporea ?. I have seen a very similar attack on Clove trees in 
Malacca. The trees appeared healthy but died suddenly, retaining 
their leaves. The death was attributed to Termites, but on digging- 
up the trees the roots and up to the collar of the tree was found to 
be coated with Mycelium in the same way as the Para rubber trees 
are. Another fungus if not perhaps the same thing, was well known 
to serve Coffee bushes in the same way. This proved to be Irpex 
flava , a yellow Polyporus, which 1 have seen attacking other trees 
ground infested by this plant was considered unfit for planting on, 
and in the days of Coffee one often saw little spots of ground 
where it was said Coffee would not grow, and this was due to the 
Mycelium of the Irpex . It did not seem to spread however, and 
often occupied an area a few’ feet square only. 
The Malays had a theory that this death of trees on special bits 
of ground, was due to a trunk of a poisonous tree lying buried 
beneath the ground, and in a sense they were not far wide of the 
mark. Irpex like alt this class of fungi is naturally a saprophyte 
living on dead timber but under certain circumstances not very 
clear becomes parasitic attacking living wood, and it is probable 
that the roots of the trees infected reached a mass of under 
ground decomposed wood infected with Irpex. Probably something 
of this kind has gone on in these estates where the Rubber trees 
