Inthe official red-list namned Sarcodon sp. nov. ‘Wombat’
This is an undescribed species, characterised during a revision of the Australian species of Sarcodon by James Douch (The University of Melbourne). DNA sequence data for two collections for ITS, LSU, and tef1 regions does not match sequences of any other species in the genus from Australia or elsewhere. A collection from Tasmania agrees morphologically, but there are no sequences available for this collection.
Description: Basidiomata simple or connate, strongly smelling of sweet fenugreek when dry. Pileus 130–165 mm diam., shape irregular in top view, plano-convex, brown, Snuff Brown (Rayner), becoming darker brown, Cigar Brown (Rayner), towards centre, margin entire, mostly inrolled but plane in some zones, networked with minute cracks, rimose, particularly in centre, exposing white, White (Rayner), context. Spines to 6 × 1 mm, shorter near stipe and margin, adnexed, approx. 120 per cm2, buff, Vinaceous Buff (Rayner). Stipe to 46 × 28 mm, central, terete, rough, white, White (Rayner); context concolourous with pileus context, solid. Basidiopores 4.56–7.02 × 3.82–6.03 µm (x̄ = 5.80 ± 0.60 × 4.65 ± 0.66, n = 30), globose to ellipsoid [Q = 1.00–1.55 (x̄ = 1.27 ± 0.16, n = 30)], tuberculate with paired tubercles, inamyloid in Melzer’s iodine, brown in transmitted light. Basidia 29.36–47.15 × 5.63–9.47 µm (x̄ = 36.61 ± 4.64 × 7.99 ± 0.90, n = 30), 1.92–3.86 µm wide at base (x̄ = 2.61 ± 0.39, n = 30), clavate, four-spored, without basal clamp, hyaline; sterigmata 3.07–6.61 × 1.10–2.33 µm (x̄ = 4.67 ± 1.11 × 1.70 ± 0.29, n = 30); basidioles 21.97–40.45 × 4.29–8.87 µm (x̄ = 29.55 ± 4.97 × 6.19 ± 1.01, n = 30), 1.97–4.78 µm wide at base (x̄ = 2.73 ± 0.53, n = 30), clavate, hyaline. Cystidia absent. Pileipellis a cutis consisting of repent, sometimes branched, septate, hyaline hyphae with few clamp connections, 2.77–6.81 µm diam. (x̄ = 4.79 ± 1.07, n = 30). Pileus trama hyphae similar to those of pileipellis but interwoven. Hymenophoral trama hyphae similar to those of pileipellis but interwoven. Stipitipellis similar to pileipellis. Stipe trama hyphae similar to those of pileipellis but interwoven and parallel. KOH reaction of squashed spine is faint Pistachio Green (Rayner). Spore print not taken.
Collections examined: Victoria: Wombat State Forest, Walter J.B. s.n., 21 Apr. 2011 (MEL 2417187); Old Toolangi Rd, between Dixon’s Creek and Toolangi, Crichton G.A. s.n., 27 Apr. 1969 (MEL 1054646 = MEL 2306426).
[Description prepared by James Douch]
Know from very few sites, this is a highly distinctive fungus in the field, and would attract attention if it was more common and widely distributed. Threatened by the very low population size.
Known from two sites in Victoria - Wombat State Forest (695 m NNW from intersection of Lyonville Springs Rd and Daylesford-Trentham Rd) and east of Kinglake (Old Toolangi Rd, between Dixon’s Creek and Toolangi).
The species has been seen once at each site in Victoria. At Wombat State Forest, in 2011, fifteen sporing bodies were observed in total, distributed across 20 m2, some in the open, many under sprawling branches of Daviesia ulicifolia. The species has not been seen at this site again, despite visits during suitable seasons in following years (John Walter, pers. comm.).
Other ectomycorrhzial fungi in eucalyptus forest with large sporing bodies (such as Cortinarius australiensis) can be observed to form fairy rings, suggesting that wide scatters of sporing bodies may represent single genets (although perhaps becoming fragmented over time). Therefore, a multiplier of five is used to convert from functional individuals (i.e one at each site) to mature individuals. Because the sporing bodies are large, a multiplier of five is used for undetected individuals at the known sites, and five for undetected sites apart from the known site. The population is therefore estimated as 250 mature individuals. There is no information on which to assess trends.
For the two Victorian collections: MEL 2417187 on soil with thin layer of litter, in lower part of gully, in tall forest of 55% Eucalyptus radiata, 45% E. viminalis, with some E. obliqua on slopes nearby, with minimal understory including Daviesia ulicifolia, Tetrarrhena juncea, and Viola sp., with Gahnia sp., Lomandra sp., and Pteridium esculentum nearby. MEL 1054646 (=MEL 2306426) beneath E. dives on dry ridge above road.
Clearing of the particular sites especially by track widening
Increase in frequency and severity of fires
Targetted surveys in similar habitats
Age of individuals, and size of genets
Douch, J.K. (2018) Phylogenetic and taxonomic study of Sarcodon, Bankera, and Boletopsis (Bankeraceae) in Australia and New Zealand. BSc (Hons) thesis, School of BioSciences, The University of Melbourne.