Mycogeography

Imports, exports and puzzles

Since the beginning of human migration, people will have been transporting organisms from one place to another. Sometimes this was done intentionally, at other times by accident. Before the advent of stricter quarantine laws, Europeans have intentionally brought numerous plants and animals into Australia. Simultaneously they have unintentionally brought various fungi into the country. Of course, numerous products have been shipped out of Australia - and with them have gone some fungi as well. In this section there'll be some examples of this unconscious "trade" in fungi. The section will finish with some puzzles - distributions for which there are not yet any convincing explanations.

Introduced by humans

While Australia now has strict quarantine laws to stop the unplanned introduction of overseas organisms, the earlier years of European settlement saw numerous foreign species introduced to the country. At one time such introductions were highly organised and carried out under the auspices of the Acclimatisation Societies of the various states, when they were separate colonies. The aims of such societies were to introduce both agriculturally useful animals and plants as well as to "beautify" Australia through the introduction of foreign animals and plants. Even after the peak of Acclimatisation Society activity, there were still many smaller scale introductions. Understandably, if you import animals or potted plants you will bring in the spores and micro-organisms in animal guts as well as the mycelia that are growing with those pot plants.

Amanita muscaria

Melanogaster sp.

As a result a number of fungi have been accidentally introduced into Australia. Quite a few mycorrhizal species have come in. To give a few examples, we have Amanita muscaria, Amanita phalloides , Hebeloma crustuliniforme , Lactarius deliciosus, Paxillus involutus, Tricholoma terreum, amongst the mushrooms; Leccinum scabrum and several Suillus species in the boletes; the truffle-like species of Rhizopogon and Melanogaster. The species involved are well-known to be mycorrhizal with various northern hemisphere trees and in Australia they are almost always found associated with the same, introduced trees and this is very good evidence that these have been introduced. It is most likely that Amanita phalloides (the Deathcap) (SEE DEATHCAP SECTION) came into Australia with imported oak trees.

Robert Brown reported Amanita muscaria to be in Australia, in his 1814 botanical appendix to Matthew Flinders' account of the Investigator voyage. However, this record demands a good helping of the healthy scepticism referred to earlier. Brown had left Australia in 1805 and collected no specimen in support of his claim, nor recorded it for any particular location in his diary. In fact no Amanita muscaria specimens are known from Australia until much later and it is possible that Brown mistook the native Amanita xanthocephala for Amanita muscaria. The two are quite different and, really, should never be confused. However, there is a specimen of the former, originally named as the latter, in the Melbourne herbarium - which lends support to the idea of mistaken identity. Moreover, Brown was not a mycologist and may have happily applied a European name after the most fleeting of glances at the Australian specimen.

In Australia Amanita muscaria is most commonly found in pine plantations, but it has also been found in Tasmanian Nothofagus forest, showing that it has adapted to a new mycorrhizal partner. A number of introduced animals and plants have become serious ecological or economic pests. Think of the rabbit and blackberry. Have any of these introduced fungi become problems? At present we don't know, but when a species such as Amanita muscaria is found in native Nothofagus forests you might wonder if it is displacing some native mycorrhizal species.

Exported by humans

Aseroe rubra

Anthurus archeri

On the other hand, a few Australian fungi have found their way overseas. In 1829 the stinkhorn Aseroe rubra, the first Australian fungus to be named (by Labillardiere in 1800), was found growing in a glasshouse at the Royal Botanic Gardens in London, on soil imported from Australia. Well over a century later, in 1993 it was found about 16 kilometres away from the botanic gardens and this was the first outdoor find of the species in Europe. Another Australian stinkhorn, Anthurus archeri, has also made its way to Europe and appears to have been carried there either through the wool trade or by Australian soldiers who fought in France during the First World War.

Hydnangium carneum is one of the many Australian truffle-like fungi. It is quite common and widespread in Australia and also in many other parts of the world. One writer commented that it appears to have gone wherever Eucalypts have gone. Interestingly enough, while a good Australian species, the original description (published in 1839) was based on a specimen collected in the botanic gardens at Grunewald, near Berlin in Germany. You would not find it too surprising to find that it has travelled to many of the major parks in continental Europe, Great Britain and North America. After all, during the 19th or early 20th centuries many eucalypts will have been imported by various botanic gardens and private plant collectors in those countries. However, Hydnangium carneum has also turned up in places you may initially find surprising, such as the Inner Hebrides and the Falkland Islands.

Laccocephalum mylittae, left and above.

The sclerotium-forming polypore Laccocephalum mylittae, previously known as Polyporus mylittae, has turned up once in New Zealand - seemingly on a railway sleeper imported from Australia. There is also some evidence that Amanita muscaria (introduced to Australia, from Europe) then moved to South America from an Australian source. It may also be that the relatively recent New Zealand occurrences of Jafneadelphus ferrugineus and Mycena viscidocruenta are due to accidental introduction by humans.

Puzzling distributions

Then there are oddities such as Hypholoma tuberosum. Numerous specimens of this mushroom were found in Vancouver, Canada over several years from 1982. They would appear in compost beds and mulch piles in cultivated parks or gardens and commonly grew out of sclerotia, which could be several centimetres in diameter. It became obvious that this was a new species and a formal description was published in 1988, when it was still known only from Vancouver. The authors commented that given no records before 1982 and the only known occurrences being in urban parks or gardens, the fungus was likely to be an introduced species.

Hypholoma tuberosum

In 1987 fungal sclerotia and fruiting bodies were found in Australia, with potted trees used as ornamental plants in commercial buildings in Sydney. After the appearance of the Canadian paper it became clear that the Sydney specimens were examples of the same species. The potting mixes contained coarse pieces of peat. Later in the same year, fruiting bodies were collected from the drier areas of Wingecarribee Swamp, between the towns of Moss Vale and Roberston in NSW. At that time commercial peat mining was carried out at the swamp. In 1990 numerous fruiting bodies were found in the sandy margins of a creek in Sydney, in the vicinity of numerous commercial nurseries. In 1995 numerous fruiting bodies and sclerotia were found in a retail plant nursery in Canberra, in a coarse peat/sand mix used to hold tree ferns awaiting sale. The nursery owner did not know the source of the peat used in that holding bed.

The fungus does not appear to be harmful to cultivated plants, nor is there any suggestion it is mycorrhizal. In the intervening years the fungus has not been found anywhere else. The question of its true home and natural range is still unanswered. The Canberra and Sydney occurrences are undoubtedly introductions via peat - but Australian or overseas peat? For many years peat was imported to Australia from Europe and New Zealand, but the species has not been found in those regions. The only natural habitat so far known is the Wingecarribee Swamp, so perhaps that's the home of the species and it was introduced to Vancouver from Australia - but investigations have shown no connection between Australia and Vancouver in the trade of peat or potted plants.

Crepidotus improvisus is a small, stemless mushroom with the semi-circular caps up to 2 centimetres across, attached directly to rotting wood by their flat edges. The species is known from NSW, Papua New Guinea, New Zealand, Chile - and Poland. Excluding Poland, the other countries constitute a Gondwanan spread. Is the Polish record correct? The Polish specimen has been examined by a competent mycologist - so there are very good reasons for accepting the identification. Perhaps the species is of Gondwanan origin and after the collision of Australasia with Asia moved north to what is now Europe. But then, why are there no records of the species between Papua New Guinea and Poland? That's a large intermediate area and surely a Gondwanan species migrating into Eurasia should have been found somewhere else in that large area. It may very well have been collected elsewhere in Eurasia and stored in some herbarium, but mis-identified. Or perhaps the species been accidentally introduced to Poland in modern times, rather than getting there at the end of a long overland migration from Gondwana.

The first account of the polypore Laccocephalum hartmanni was published in 1883 by the English mycologist M.C. Cooke, on the basis of a specimen found in Australia. He used the name Polyporus hartmanni and it was known by that name for many years. For over a century this species was known only from Australia but a paper in 1995 reported the first non-Australian record, from Japan. Interestingly, it turned out that a specimen collected in Japan in 1931 was an example of this species.