I was recently given a specimen of a most unusual fungus. Jo Mann, one of my U3A students, had collected it at Moggs Creek, just off the path on the road to the lookout over Fairhaven. It was on the dry side of the hill, and the fungus was lying on the top of the soil. It was more or less round, soft and spongy but with a tough dark brown skin, and appeared to have been dug up, for there were particles of clayey soil and fine rootlets adhering to ft. Jo took it home, put in on the back veranda, watered it sporadically, and even broke off a piece to give to her grandson. For three weeks ft showed no change, then it began to develop a white spongy growth close to the broken-off area. At the same time the ball began to harden and collapse inwards.
It was found on 5th March and brought to me on 5th April. I kept it in a plastic bag in a warm room. The fruiting body continued to grow. Each morning when I took it out, it was covered with droplets of moisture, the flesh a fresh, velvety white with sulphur yellow patches which faded as the day progressed. It developed no real stem, but spread out in a series of lobes, with fine closely-packed pores on the under surface. I photographed it often. After a week it appeared to have reached its optimum size, so I removed the bag and placed the fungus on a sheet of black paper, hoping to catch some spores, but in this I was unsuccessful. The fungus merely gradually dried up and shrank in size and weight. The fruiting body (sporophore) became firm, cream or buff-coloured and the ball (sclerotium) wrinkled, contorted and extremely hard. At no time did it have a strong smell and it was not attacked by insects. On 11th April I noticed a curious blue-green to grey patch, I cm in diameter, like a secondary mould. This remained constant as the sporophore shrank.
Polyporus mylittae is unusual in that is more commonly known from its vegetative stage than from its fruiting stage. It produces large underground food reserves known as sclerotia, which were ploughed up in great numbers by early farmers. They are commonly found in forest or woodland, were very numerous in Gippsland and well-known from the Otways. They lie from a few centimetres to more than a metre below the surface and look something like large potatoes, varying in size from an apple to a soccer ball, and up to 15 kg in weight. Sclerotia are composed of a dense mass of fungus mycelium, the individual strands of hyphae being closely interwoven, enclosed in a thin rough crust that may flake off with age. When cut or broken, the interior is seen to have a rice-pudding appearance, with waxy-yellowish compartments of irregular shape separated by white walls (septa) less than 2 mm thick. The sclerotium shrinks as its food reserves are used by the fruiting body.
The sclerotium may remain dormant for many years before producing one or more fruiting bodies. Fruiting was first described by Henry Thomas Tisdall in a paper read before the Field Naturalists Club of Victoria on 11th November, 1885. Tisdall realised that the species was one of the polyporoid fungi, whose spores are produced in a series of tubes rather than along radiating gills. The spores are white. It is not known what stimulates the fungus to fruit. Perhaps it is damage to the skin. Tisdall first noticed a 'whitish-looking substance oozing through in two places, one portion from what I then imagined to be the stem, and the other from the cut side of the fungus'. He put the cut side face down to get rid of "the mould", and when he next visited it, 'the new growth had made wonderful progress" and had raised the whole specimen nearly half an inch. He put his collection away in a cellar and two months later found more fruiting bodies.
The species was formally described in 1892. Scierotia were first reported in 1834 and were thought to be a kind of native truffle. Since sporophores are so rarely found on buried specimens in situ, it has been suggested (Sinnott 1974) that animals such as wombats or bettongs might assist in triggering fruiting behaviour and dispersal of spores. It has also been claimed that fire is a stimulant.
Polyporus mylittae is commonly known as Blackfellows' Bread and was an aboriginal food. Dr. Milligan saw Tasmanian aborigines eating it. Aldo Massola cites it as being sought by aborigines at Lal Lal, Tisdall asked Alfred Howift (who was later to write the authoritative The Native Tribes of South-east Australia) and received conflicting replies.
As to its palatability, Jim Willis wrote " ... it is almost incredible that such hard sclerotia could have been eaten at all - in the fresh state they have somewhat the consistency of very rubbery gristle, while dried examples are always as hard as horn". Tasting tests on raw material were carried out by members of the Victorian Archaeological Survey at Yambuk in December 1976 and in Melbourne in January 1977. Everyone taking part agreed that it was not unpalatable, although somewhat bland and even slightly sour. Trevor Pescott relates that Bill Robertson, as a lad in Forrest, used to eat slices raw. Trevor was also told of a member of a forestry crew who 'used to cut it up into slices, fry it in the pan, then eat it with honey and butter. Its taste is said to be unchanged in cooking.
The sclerotium when freshly dug could resemble a cottage loaf just out of the fire; the fruiting body reminded me of rising bread dough. When Dr Milligan asked the aborigines how they found the native bread, they universally replied, 'A Rotten Tree." This gives a clue as to the original source of nourishment and energy for the sclerotia. Polyporoid fungi help to break down dead and decaying organic matter in soil, lifter or wood.
Scierotia which have not fruited become very hard and have been put to a variety of uses. Nigel Sinnott used one as a doorstop and thought it would make a good cannonball. There are reports of them being made into walking-stick handles and Trevor Pescott photographed one hand sculpted from Blackfellows' Bread perhaps a hundred years earlier.
A visit to the Internet shows that the fungus is also used in herbal remedies. Polyporus mylittae is one of the ingredients in a 'natural" de-wormer for cats and dogs. It is not clear what the source for the ingredients is, but the trade could pose a serious danger to the species, which is one of Fungi map's target species (1 1 records to 27 March 2000).
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Tisdall, H.T. (1904). Notes on the 'Native Bread' Polyporus mylittae. Vic. Nat. 11: 56-59.
Willis, J.H. (1950). Victorian Toadstools and Mushrooms. FNCV, Melbourne. www. holisticgoid. corn (5/04/2000). Natural De-wormer for Cats and Dogs.