(Trappe et al. 1996)
“Mesophellia castanea resembles M. arenaria, but the latter has fusoid rather than ellipsoid spores and lacks the strong gelatinous thickening of cell walls in the endocutis and core tissues that characterises M. castanea. Both have yellowish brown spores and a capillitium of radiate hyphae and hyphal strands. The holotype lacks the epi- and meso-cutis, which are fragile and brittle, and shatter when a specimen is cut open. The resulting debris evidently was discarded. Traces of these structures are present on the Scamander River collection, however, and the full structures are evident on the Claridge and Rodway collections.”
This species has 19 independent records, all within south-eastern Australia. The last record of this species was in 2001 despite other Mesphellia spp. being recorded in a similar location. Threats to this ectomycorrhizal species include loss of habitat and mammal dispersers.
Based on records the Extent of Occurrence is ~360,000 km2 and Area of Occupancy 52 km2. The records are incomplete with regards to exact locations, but conservative estimates for the number of locations are 1 for South Australia, 6 for Tasmania and 4 for Victoria/New South Wales subpopulations. The total number of locations is at least 4 times as high as this (44 locations). There are no data to estimate the number of functional and mature individuals at each location. I used a template multiplier of 5 functional individuals which can potentially give rise to 2 ramets each for each location. Therefore, the estimated number of mature individuals for this species is 44*5*2 = 440 individuals. This places it as Vulnerable under D1. However, the small Area of Occupancy compared to the large Extent of Occurance is probably due to a lack of adequate survey effort and the full distribution is yet to be realised. Further work is needed to confirm the continuance of the South Australian population and the extent of the Tasmanian subpopulation in order make a more accurate assessment.
The presence of specialist mycophagists at the locations where this species is found ensures on going dispersal. However, some of these mammalian dispersers are endangered, threatened or extinct within M. castanea’s range.
This species has been recorded in the South Australia, Victoria and Tasmania. The populations most probably also include south-eastern New South Wales.
Based on the rule that subpopulations are >500 km from each other, there is likely to be three subpopulations: 1) Tasmania; 2) south-east New South Wales and Victoria, and; 3) South Australia.
Collections by L. Rodway and C. Brittlebank, made in South Australia and Tasmania, do not have a collecting date but are most probably early 1900’s or earlier (the Index of the C.G. Lloyd Mycological Collection were presented to the Smithsonian Institute in 1928; http://mycoportal.org/portal/taxa/index.php?taxon=Mesophellia castanea). They also do not have accurate location data associated with them which makes it hard to infer whether these early collections represent populations that still exist.
Of the collections that do have dates, the earliest is in 1886, collected by S. Wintle in Tasmania by Scamander River. The exact location is unknown and this river is very long. Other collections from Tasmania are by L. Teakle in Feb 1987 at “Crosswell Flats, SW of Mt Lloyd” and by N. Bougher in May 1990 from “N of Cranbrook”.
Most collections of M. castanea are from eastern Victoria (11 of 19 records). Of the 10 that have collection dates from Victoria, the earliest are from 1963 (two collections from G. A. Crichton, MEL 2061464A) and 9 were collected in 1990/91 in East Gippsland. These latter collections were all made from a study by Claridge et al. on plots that were visited many times (Claridge et al. 2000). M. castanea has only been recorded once since (2001 by A. Jumpponen in East Gippsland), despite other Mesophellia spp. being recorded in similar locations in the 2000’s and 2010’s (ALA records).
I have provided a screenshot of a map using rough coordinates for each location loaded into http://geocat.kew.org/
If we make the conservative assumption that the records without exact location data all come from different locations then the number of location per subpopulation are:
1) 1 location for South Australia
2) 6 locations for Tasmania
3) 4 locations for eastern Victoria/New South Wales (lumping together collections <50 km from each other).
All members of Mesophelliaceae are thought to be ectomycorrhizal and incorporate ectomycorrhizae in their peridium.
M. castanea has been listed in habitats with Eucalyptus cypellocarpa, E. globoidea, E, muelleriana, E. sieberi, E. globulus, Eucalyptus baxteri, Eucalyptus gummifera and other eucalypts and Acacia mucronata, Acacia terminalis and other acacias. It has been collected in January, February, May-August, September and December.
All Mesophellia sp. require animals for dispersal, mainly mammals. The mammals break open the crusty outer layers to reach a sterile edible core. In doing so the powdery spores are dispersed via either ingestion by the animal, carried on the outside of the animal or dispersed via wind or soil movement.
- Sequencing of specimens and phylogenetics
- habitat characterisation and ecotomycorrhizal host range
- Identification of Mesophellia sp. collections in herbaria (note: there are 111 records of on the Australian Living Atlas recorded as Mesophellia sp.)
Trappe, J. M., M. A. Castellano, and N. Malajczuk. 1996. Australasian Truffle-like Fungi. VII. Mesophellia (Basidiomycotina, Mesophelliaceae). Australian Systematic Botany 9:773–802.