Pisolithus tympanobaculus T. Lebel & M.D. Barrett, 2018

Lebel, Teresa, Pennycook, Shaun & Barrett, Matthew, 2018, Two new species of Pisolithus (Sclerodermataceae) from Australasia, and an assessment of the confused nomenclature of P. tinctorius, Phytotaxa 348 (3), pp. 163-186 : 173-174

Pisolithus tympanobaculus T. Lebel & M.D. Barrett sp. nov. ( Fig. 9 )

Mycobank: MB820206

Differs from other Australasian species in distinctly drumstick or club-like sporocarps, spores ornamented with robust short spines, 0.4–0.7 μm tall × 0.2–0.4 μm broad, coalescing into short robust secondary conical warts.

Type: near Albany, Two Peoples Bay Reserve, Western Australia, Australia. 27 June 2001, R.E. Beever & T. Lebel REB2016 (holotype PDD 75026).

Etymology: In reference to the typical shape of sporocarps, tympanum (drum), baculus (stick) (L) for a drumstick or club-like.

Basidiomata subglobose to elongate, 28–35 mm wide × 35–48 mm high, excluding pseudostipe; pale yellowish tan with blackish patches. Peridium at most 4–10 mm thick, soon thinning to show outline of peridioles below, finally disintegrating and leaving pale yellowish tan, ochre- or blackened patches. Peridioles globose to subglobose, 1–2 (rarely 3) mm diam, solid, moist, cream-colored at first, becoming pale ochre then dark olivaceous brown, before drying to powdery mustard yellow spore mass when mature, compressed in uppermost part, often forming in stipe apex. Pseudostipe central, cylindrical or tapering to base, 12–22 mm wide × 25–35 mm long, generally appearing solid but sometimes excavated/divided; similar colours to peridium, but yellow to gold at base, blackening on exposure. Rhizomorphs yellow to golden.

Basidia none observed. Spores globose, (6–)7.5(–8.5) μm diam [mean 7.4 ± 0.3 × 7.5 ± 0.35], Q = 1.05–1.09 [mean = 1.06]; ornamentation of robust short spines, 0.4–0.7 μm tall × 0.2–0.4 μm broad coalescing into short robust secondary conical warts. Spore colour in KOH pale yellow to brown, non-amyloid, non-dextrinoid.

Ecology and distribution: epigeous, solitary or in small clusters in eucalypt forests or plantations. Season: (June) Winter. Australia, Western Australia.

Additional specimen examined: AUSTRALIA. Western Australia: near Albany, Two Peoples Bay Reserve, 27 June 2001, R.E. Beever & T. Lebel REB2017 (PDD 75025).

Notes: Unfortunately we were unable to locate several relevant collections to examine morphology for various sequences deposited in GenBank, therefore the description is based upon two collections found in the New Zealand Fungarium PDD. The following collections are included here based on sequences deposited in Genbank: Western Australia, Scott River, MU98/8, AF374648; Scott River, MU98/6, AF374646; Kudardup, MU98/19, AF374658; Kudardup, MU98/18, AF374657; Northcliffe, MH155/CSH1101, AF374671; New South Wales, Royal National Park, coastal region, ‘R1’,KF68347.

The strongly supported sister clade P.‘ Lebel sp. 3’ to Pisolithus tympanobaculus consists of 2 sequences, 1 each from New South Wales and China (probably as an ectomycorrhizal associate of eucalypt species in plantations). While we do not feel there is sufficient evidence to describe another new species at this point, several unique indels and high support for the sister relationship between P. tympanobaculus and P.‘ Lebel sp. 3’ suggest that there is more diversity to be found.

Figures

FIGURE 9. Pisolithus tympanobaculus sp. nov. a–b sporocarp (PDD75026); c–d SEMs of spores (PDD75026); e spores (PDD75026).