Brahmaculus P.R.Johnst., 2021

Johnston, Peter R., Park, Duckchul, Smith, Matthew E., Mujic, Alija B. & May, Tom W., 2021, Brahmaculus gen. nov. (Leotiomycetes, Chlorociboriaceae), MycoKeys 80, pp. 19-43 : 19

Brahmaculus P.R.Johnst. gen. nov.

Type species.

Brahmaculus moonlighticus P.R.Johnst.

Etymology.

From Hindu mythology, named after Brahma, the four-headed creator god, reflecting the multiple heads of the apothecia, and the masculine diminutive -culus.

Diagnosis.

Phylogenetically Chlorociboriaceae , distinguished from Chlorociboria by its terrestrial habitat, and apothecium with stipe branched near apex, each branch with an apothecial cup.

Description.

Apothecia stipitate, yellow rhizomorphs at base of stipe, the stipe branched apically several times, each branch holding an apothecial cup. Receptacle and stipe densely covered with short hairs. Hairs more or less straight, cylindric, thin walled, with a few septa, pale brown intracellular pigment, externally densely encrusted with yellowish material, encrusting material dissolving in KOH + Melzer’s reagent. The hymenium within each apothecial cup is typically divided into smaller segments, with areas comprising asci and paraphyses separated by clumps of hair-like elements. Excipulum comprises cylindric cells arranged more or less parallel to the surface, cells mostly long-cylindric, but sometimes with outermost 1-2 layers of cells short and broad-cylindric, cell walls slightly thickened, hyaline, cells near base of hairs with pale brown vacuolar pigment. Asci with wall thickened at apex, amyloid pore extending through the wall, flaring near the inside and especially toward outside of the wall, 8-spored, with croziers. Paraphyses simple or tapering to apex, of similar length as asci. Ascospores oblong-elliptic, 0-septate, hyaline.

Notes.

The four species described below are phylogenetically distinct but remarkably similar morphologically. There appear to be small differences in size and colour of the apothecia and shape of the paraphyses and hairs but having only a single specimen available for each species makes the significance of these differences difficult to assess. The rhizomorphs at the base of the stipe appear to be associated with tree roots. Based on the collecting sites, in South America and New Zealand the roots are likely to be Nothofagaceae , in Australia they may also be Nothofagaceae but Eucalyptus species were also growing in the vicinity. Observations from the South American specimens showed a loose weft of mycelium around the Nothofagaceae roots but there was no clear evidence of a mantle or ectomycorrhizal association. It is possible that these fungi are root endophytes, or perhaps parasites of Nothofagaceae -associated ectomycorrhizal fungi.