Autophagomyces incertus W. Rossi & M. Leonardi, sp. nov.

Index Fungorum number: IF 559783; Mycobank number: MB 559783; Facesoffungi number: FoF 12769; Fig. 1

Etymology – From Latin, meaning uncertain, because of the uncertain taxonomic position of the new species.

Holotype – CAMB WR2471.

Thallus uniformly straw-yellow. Basal cell of the receptacle (cell I) tapered downward to hyaline and aciculate tip of foot. Cell II quadrangular, slightly longer than broad, its outer margin slightly concave. Cell III relatively large, wedge-shaped, united on the inside to cell II, reaching the base of cell VI and the top of cell I. Appendage simple, free, consisting of 5 superposed cells, the lower two of which are slightly longer than broad, the third subquadrate, the fourth much smaller and broader than long, bearing an antheridium on the inner side, while the fifth, slightly larger than the forth, bears two antheridia. Antheridia with a very narrow and slightly curved efferent tube, the terminal one bearing a tiny and hardly visible spine. Cell VI short, about as long as maximum width, abruptly constricted at the base. Cell VII and basal cells relatively large and elongate, forming together a stipe slightly exceeding the ascigerous part of the perithecial body. Perithecium slightly asymmetrical, with the ventral side more convex, broadest below the middle, than tapering upwards, becoming abruptly narrower just above the median tier of the outer wall cells, than nearly uniform in width, the tip rather abruptly and symmetrically tapered, the apex rounded. Length from foot to perithecial apex 285–330 µm; length from foot to tip of uppermost antheridium 160–165 µm; perithecium, including basal cells 200–225 × 70–75 µm.

Material examined – Australia, New South Wales, Headwaters Lookout Barrington Tops, in leaf litter, 19 January 1992, leg. V. Lorimer, on the dorsal side of the abdomen of Palimbolus sp. (Coleoptera, Staphylinidae, Pselaphinae) CAMB WR2471 (holotype).

Notes – Utilizing the key given by Tavares (1985), the inclusion of this fungus within the genus Autophagomyces is out of question. The new species also displays at least five of the seven characteristics listed by Benjamin (2001) for Autophagomyces in the limited concept. A sixth remains
uncertain, because the structure of the trichogyne is not visible in the available thalli. The only feature in contrast with Benjamin’s concept of the genus is the presence of a spinous process on the appendage, which is not, in our opinion, a conclusive feature. The fact that the spine, which is actually
the remain of the original spore apex, is sometimes minute and evanescent, and has been observed in only one of almost 700 recognized species of Laboulbenia (Dima et al. 2021) and in only one of the 91 species of Rhachomyces (Santamaria et al. 2020; Buyck et al. 2021) would seem to support our opinion.

Figure 1 – Autophagomyces incertus (FI WR2471, holotype). Scale bars: 100 µm