A healthy population of one of the rarest fungi in Australia and New Zealand has been found, on a protected island in the state of Victoria.
Photo: Supplied / Michael Amor, Royal Botanic Gardens Victoria
'Tea-tree fingers' is so named because it appears as crusty, finger-like brown lobes gripping dead branches of mānuka and other trees.
The species had been recorded at half-a-dozen sites in Australia, and just two sites in the South Island - although it hasn't been seen at one of those, in Arthur's Pass, since the 1980s.
Australian mycologists search for it often, and usually without success, but a recent expedition on French Island, south of Melbourne, found dozens of these strange mushrooms.
The Royal Botanic Gardens of Victoria, which led the quest, said the discovery of possibly as many as 100 individual fruiting bodies makes this population greater than all the previous known populations of tea-tree fingers, combined.
That is significant for a species that is on the international Red List as critically endangered.
The project officer for tea-tree fingers at Victoria's botanic gardens, Sapphire McMullan-Fisher, said finding a population within the protected national park of French Island had greatly improved the prospect of the species' survival.
But the fungus, which has the formal name Hypocreopsis amplectens, is not out of the woods just yet. Actually, scientists really want to find it in many more woods.
Dr McMullan-Fisher's co-leader in the expedition, Michael Amor, said the relatively high abundance of tea-tree fingers in the pristine island environment could be an insight into what mainland populations once looked like - "that is, before human-driven disturbance and habitat loss".
H. amplectens is threatened on the Australian mainland by the destruction of its forest habitat by both bushfires, and land clearance for mining and other activities.
Similarly in New Zealand, any clearance of native bush can be presumed to reduce the chances of finding as-yet undetected populations; although the two known sites here are both in conservation reserves.
The scientific paper that first described this species in 2007 noted that further investigation was needed into why it is rare in this country.
Observations made since then have supported a theory that tea-tree fingers make life a bit harder for themselves, as they seem to require not just the timber that they live on, but also the presence of another crust fungus, Hymenochaete, which they are thought to feed on.
Tea-tree fingers were first collected in New Zealand at Klondyke Corner in Arthur's Pass National Park in 1983, but as with the pavlova, the Australians will claim to have the first specimen.
In this case it's justifiable though, because that lone collection in New Zealand's national fungarium sat there for years, dried and unidentified in a box, until work began in earnest to identify subsequent specimens from Australia.
That work was completed with the publication of the paper in 2007, in a joint effort by scientists from both sides of the Tasman.
The species has not been seen again at either of the New Zealand sites where it has previously been observed: Klondyke Corner (1983) and the Waterfall Track, near Hanmer Springs, where it was photographed in 2006.
Mycologists want anyone who thinks they have come across it to record their sighting using iNaturalist, but not to disturb or collect the tea-tree fingers.
