Pileus: diameter 3–19 mm, rounded to convex, semi-circular to shell shaped, margin wavy; brown, smooth texture, sparsely hispid becoming more densely so near attachment, hairs erect, white to pale fawn, flesh firm, dry, thin. Spines: 1–3 mm long, attachment decurrent, blunt, length increasing towards the stipe. Stipe: at times very short to almost absent, if present 1–7 × 3 mm, laterally attached, pale fawn. A basal mass of white hairy fibres fixes basidiome to substrate. Hyphal composition: monomitic, consisting of thick walled hyaline generative hyphae (2–8µm wide) and hyaline to pale yellow gloeoplerous or oleiferous hyphae (–8µm wide), hyphae in the pileipellis irregularily but occasionally heavily encrusted with brown pigment, clamps present throughout all tissues. Basidia: 15–34 × 4–7 µm, subclavate, with (1–)4 sterigmata, basal clamp present. Gloeocystidia: arising from gloeoplerous hyphae –12 µm in diameter, occasionally hymenial (38–50 × 7–10 µm), clavate, projecting beyond the basidia, staining dark purple to black in sulpho-vanillin otherwise hyaline to pale yellow in 3% KOH. Basidiospores: 5–6(–7) × (3.5–)4–6 µm, Q = 1.1–1.2, globose or subglobose to ellipsoid, amyloid, with fine verrucose ornamentation. Specimens Examined: AUSTRALIA. VICTORIA. Blackwood, Jack Cann Reserve (opposite the Garden of St Erth) Great Dividing Trail on the northern side of the Lerderderg road, 2.vii.2006, FNCV 55 (MEL 2305170); 1.vii.2007, FNCV 69 (MEL 2323326). Description prepared by Brian Claus & Tom May.
A highly distinctive, although as yet undescribed species. Known from only two sites. It is highly recognisable in the field, and has been a species of interest for citizen scientists in Australia for a number of years. Threatened by the very low population size.
This species has been observed for a number of years on a single Eucalyptus radiata tree near the carpark at Jack Cann Reserve Great Dividing Trail on the northern side of the Lerderderg road, Blackwood. Lat 37°28’46” Long 144°17’29”, Victoria, Australia. Recently, a second site was discivered at Olinda, in the Dandenong Ranges, to the east of Melbourne, Victoria.
Known from two sites, where it is present on only one tree. At Blackwood, there are few sporing bodies. The colony at Olinda is larger. It is assumed that there are two mature individuals per tree. With allowance for 5 other trees at each site that harbour the fungus (but as yet undetected), and 5 times the number of sites (to allow for undetected sites), the population is estimated at 500 individuals, but this should be seen as an upper estimate, and the number of mature individuals could well be much less than this. There is no information on which to assess trends.
Both occurrences are on the bark of a living tree, Eucalyptus radiata, in native forest. At Blackwood, the forest is eucalypt open forest with Eucalyptus radiata, Eucalyptus viminalis and Eucalyptus obliqua and an understorey of various Wattles, Banksias and peas. Fruit-bodies have only been observed in the months of June and July, but it those were the only months the Field Naturalists Club of Victoria has conducted forays in the area since the fungus’s discovery except for one foray in May 2015, which yielded no sightings.
The Blackwood site has not been burnt for some time. The Olinda site appears to have been burnt in the last few years. Fire is a natural occurrence in eucalypt forests. The frequency and severity of natural fires is expected to increase with climate change. It is unclear how Auriscalpium sp. “Blackwood” survives fire, or how it colonises new substrates after fire. Fire is a potential threat to the fungus itself, as strong fires will burn into the thick bark of stringybark eucalypts and may kill the fungus. In addition, although eucalypts are adapted to survive fire, severe fires may kill mature trees, in which case, while a tree may remain standing for some time, the bark is decomposed and shed within a few years, removing the particular substrate of the fungus.
Establish cultures to allow ex situ conservation efforts.
Monitor planned control burning
Increase survey effort in the immediate locality to try to find further occurrences.
Monitor the known occurrences to see if the extent of the fungus is spreading on the known tree host, and what is the distribution of sporing-bodies over time.