Ileodictyon garnierii is a distinctive species, easy to identify in the field. Distribution is limited to rain forests. The habitat is largely unmanaged and undergoing change due to feral animals.
There have only ever been 3 functional individuals of this fungus found from three sites. Using the Dahlberg & Mueller (2011) methodology we estimate that, allowing for the known and as yet undiscovered sites, there might be up to 10 sites and a population of up to 50 mature individuals. This takes in to account the very steep and inaccessible terrain of a substantial part of the Mont Buou site.
This species is assessed as “ critically endangered” on the basis of criteria B1, B2a and B2b with only three known sites and a potential of 10 sites in an endangered ecosystem and D1 on account of the a very small estimated population of less than 50 mature individuals.
Fruit body: emerald green, open-lattice cage; 60 - 150 mm diameter; often detaching from the volva upon full maturity; the arms are joined to create a cage-like structure withoval egg-shaped spaces in the net;the outer surface is typically wrinkled and may have a groove, the inner surface is usually more roughly corrugated across the width. Internally the arms consist of thick walled tubes.
Egg: dingy white, up to 30 mm diameter, with white rhizomorphs at the
base. The egg remnants become a whitish volva as the fruiting body emerges, however, the receptacle often detaches itself and may be carried by the wind for some distance from the place or origin.
Stipe: absent, but the remains of the egg form a volva like base.
Flesh: brittle and spongy.
Gleba (Spore mass): olive-brown or sage-green, thick and slimy, carried on the inner surface of the arms.
Smell: foetid, of rotting meat or faeces, and “faint, smelling of cheese”.
Notes: this cage fungus is recognised by its form and emerald green colours. So far only known from New Caledonia.
There appear to be few endemic Phallaceae species in New Caledonia. This species is readily recognized because of its cage-like form and emerald green colours. It was found in the high mountain forest reserve of Mont Buou in 2000. In the decade that has passed since its first being seen, the SMNC have visited most of the remaining areas of forest and it has only been seen again once. We may reasonably assume that this fungus species is naturally rare.
There has been no system of formally recording fungi in New Caledonia in the past. Le Rat made many fungal collections between 1900 and 1910 some of which were then described and published by Patouillard. Roger Heim published some further species in the 1930s. Horak visited New Caledonia during the 1970s and published several papers during that decade. It was not until 2009 (?) that a more formal system was established to monitor fungi, following Marc Ducousso’s formation of the Societe Mycologique du Nouvelle Caledonie. Since then some 25,000 fungi have been photographed by members of the SMNC and these form the basis of current records. There was also a formal survey of dry sclerophyll forests in 2010 directed by Ducousso which sets a base line for that forest type. In 2001 a website was established by Endemia NC to provide a record of all New Caledonia’s wildlife. In its early years it concentrated on birds and NC’s rich plant flora. It has recently (2018) started to accumulate fungal records.
The paucity of data might suggest that all NC fungi should be considered as data deficient. However for well defined species and particularly for those which can be reliably identified from photographic evidence we can claim relatively good information on current distributions but not on population trends. Ileodictyon garnierii remains known from collections at two sites.
A saprotrophic fungus that is restricted to lowland wet forest habitats.
Only a very small portion of the original forest cover of New Caledonia remains. Clearing in the past for timber and to create grazing and agricultural land have destroyed much of the forest cover. Wild fires and open cast mining have also accounted for extensive losses. What remains is now partially protected by Botanical Reserves of which Mont Buou is one. There is however virtually no active management to encourage regeneration or to discourage invasive species.
Pigs are very numerous throughout New Caledonia’s forests. Thought to be the the legacy of Captain Cook’s visit in 1774. The gift of 12 Rusa deer to the Governor of New Caledonia in 1862 has resulted a large current population; estimates range from 400,000 to 1,000,000. There are also established populations of feral cattle and horses in parts of New Caledonia. All these introduced species cause damage to native forests, in particular through selective grazing which impedes regeneration, changes species composition and through nutrient enrichment and digging (pigs) and compaction (horses and cattle).
Pigs are the main pest species at Mont Buou and at Touaourou and probably specifically target fungal species. There is no known published research on the effect of pigs on the genus Ileodictyon.
The three locations for this taxon are all threatened by fire which are increasing in frequency and severity which may well relate to the changing climate.
Recognition of the role of fungi in the ecology of forests by including references in management plans would be helpful. More effective control of feral animals would be beneficial.
Research on the effects of feral animals on vegetation is ongoing but needs to be extended to cover fungal populations.
Atlas de la Nouvelle Caledonie (1983). Auteur? Imprimerie H. Dridé
Global Biodiversity Information Facility: gbif.org
Endemia NC. http://endemia.nc/
Horak E. & Mouccha J. (1998). Annotated check-list of New Caledonian
Basidiotmycota. 1. Holobasidiomycctcs. Mycolaxon 68: 75-129
Patoulliard N. (1887). Champignons de la Nouvcllc-Calcdonie (I) Bull
Trimestriel Soc. Mycol France 3: 168-178