254 
THE LARGER FUNGI 
The ooeurrenee in 8outli Australia of Silver Leaf disease, with fructifications 
of the fungus, was first cstablislied by Mr. G. Samuel, then of the Waite Institute, 
about 1927. Ivatcr Mr. S. U. iTarrett and Mr. E. Leislunau found that the disease 
had lobtained an extensive hold and the latter published their results in ' ‘ The 
•lounial of the Department of Agriculture of Soutli Australia,” XXXIV., 1930- 
1931, page 1010. Tlie fungus is a wound parasite, the spore lodging on areas 
that have recently been injured as by pruning, by the breaking of branches or by 
bruising. The resulting mycelium then penetrates along the vessels of the branch, 
extending in this way more readily vertically than laterally. In older wounds, a 
gum iiarrier prevents such extension and the invasion consequently remains 
localised or is overcome. Varieties of fruit trees that gum readily are for this 
leason more resistant to attack, and in these natural recovery may loccui'. In the 
more susceptible kinds, Mr. Leishman estimates that the tree is probably killed 
in from three to six years. The f(diage borne on an infected branch is apt to 
become silvery early in the attack before the branch dies, owing to some toxic 
substance which is secreted by the mycelium, is transferred to the leaves and there 
causes partial separation of the cells in the leaf. The resulting abnormal air 
spaces reflect the light in such a way as to cause the silvery appearance. Such 
silvering of the foliage in various plants, due to this histological change, may be 
liroduced by lother causes, so that it is necessary to find the fruiting stage of the 
fungus before a ” Silver Leaf ” disease can be certaiulv attributed to S. 
purp u reum . 
All branches showing Silver Leaf should lie cut off well below the point of 
(mtrance of the fungus and it should be seen that this is beyond the discoloration 
of the wood indicating penetration thus far by the mycelium. Such infected 
wood should be at once burnt to j)revent the formation of fruiting bodies. When 
the fungus forms its series of little brackets on old infected branches, these 
discharge millions of spores <luring the period when I'ain is falling. Pruning 
operations at this time are fraught with danger, if through neglect any sporo- 
phores of the fungus are in the neighbourhood. Dr. F. T. Brooks recommends 
covering the wounds with soft grafting wax or an antiseptic paste of the follow- 
ing formula: — To 21bs. of white lead paste (as Ijought) add two teasi)Oonfuls 
of paste driers and two tablcspoonfuls of linsee<l oil. Mix. Then add 2 table- 
spoonfuls of turpentine and mix well. The better the nutrition of the tree, the 
more resistant is it likely to be to attack. 
407. Stereum umbrinum Berk, et Curt. (Syns., Hymenochaeie crassa (Lev.) 
Berk.., Cooke’s llandl)ook of Australian Fungi, No. 1044; H. pnrpwea Cke. 
et Morgan, Cooke No. 1 04(i ; 11. Kalchbrenneri Massee, Cooke No. 1048; 
Cortioi'Um ymirinum Thum. ; Stereum membraneteeum Berk, et Curt, as deter- 
mined by C. (t. Lloyd; and probably S. papyrinum Mont, as concerns 
Peniophora papyrina Mont., in Cooke No. 1049, p. 11, figure 82). {Umbrmus, 
umber). — Effused with occasionally a slightly reflexed margin which may be less 
than .(in. (4 mm.) deep, often forming extensive patches up to Oin. (15 cm.) 
long, tending to crack into small areas. Pilelis when present pilose, pallid, 
llymenium Snuff Brown (xxix'.) to Bister (xxix.), Avellaneous to Wood Brown 
aiid Army Brown (XL.), paler round the edges with tints of Vinaceous Purple 
and Vinaceous Lilac (XLiv.), in the fresh plant often forming extensive areas 
of the periphery, periphery sometimes Tawny Olive (xxix.). Cystidia elongated 
acuminate or slightly fusiform, slightly rough, brownish or vinaceous purple, 
.38 to 110 X 4 to 8.5 | 0 t, occasionally 190 to 300 x 5.7 y. S])ores slightly cnirved, 
7.5 to 8.5 X 3.5 y. South Australia — Mount Lofty, Stirling West, Kuitpo, 
Encounter Bay, Kalangadoo (S.E.). March, May to July. 
LLOYDELLA Bros. 
(After Dr. C. G. Idoyd, the American mycologist who assisted very materially 
in tlie study of the higher forms of Australian fungi.) 
Like Stereum but with hyaline cystidia. Here included under Stereum. 
See Stereum radiato-fis.'siim, S. illudens, and S. umbrinum. 
HYMENOCHAETE T,ev. 
(Gr., hymene, a membrane; chaitii, long flowing hair.) 
“Receptacle coriaceous, firm, sessile, eff'uso-reflexed or resupinate. Hymenium 
inferior, with an intermediate layer, sctulose or velvety, even, rarely granular. 
Si)ores white or coloui'ed, elliptical, oval, subglobose, oblong, fusoid or cylindrical 
elliiisoid; smooth. Cystidia or setae present, coloured. Perennial. Gi’owing on 
wood. ’ ’ — Rea. 
