Laboulbenia clavulata W. Rossi & M. Leonardi, sp. nov.
Index Fungorum number: IF 900425; MycoBank number: MB 600425; Facesoffungi number: FoF 14179; Fig. 1
Etymology – From Latin clavula, which means “small club”, referring to the habitus of the fungus.
Perithecium grayish brown, very dark in older thalli; the rest of the fungus is pale brown, variably darker, especially in older specimens, along the outer margin of cell III and IV and much paler in the lower portion of cell I. Basal cell of the receptacle (cell I) elongate and almost cylindrical, sometimes bent above the foot. Cell II about as long as the previous, slightly enlarged above, separated from cell III by a short, transverse septum and from cell VI by a much longer, oblique and slightly concave septum. Cell III about as long as cell II but narrower, its inner margin more or less concave. Cell IV slightly longer than cell III, its upper outer angle somewhat prominent below the insertion cell. Cell V relatively large, with the upper, convex margin free between the perithecium and the oblique insertion cell, which is narrow and thick. Outer appendage consisting of a large lower cell about twice as long as broad, followed by a slightly longer cell which gives rise to two elongate branches that are similar in size, but differ in colour, with the outer branch darker, sometimes distinctly so; these branches are invariably broken in mature thalli. Basal cell of the inner appendage much smaller than the outer, bearing a single, slender antheridium soon replaced by a simple branch much shorter and slenderer than the branches of the outer appendage. Cell VI small, subquadrate or irregularly trapezoidal. Perithecium elliptical, relatively narrow, with the whole inner margin united with the receptacle, the free, blackish tip tapering to a rounded apex, the lips outwardly oblique, hyaline about the pore. Length from foot to perithecial apex 265–395 µm; longest appendage 485 µm; perithecium 115–155×55–70 µm; ascospores about 55 µm.
Material examined – Australia, Tasmania, Crade Mt., 21.I.1991, leg. M. Daccordi, at the apex of the elytra of Agonica simsoni Sloane (Coleoptera, Carabidae, Peleciini) (CAMB WR1804a, holotype; FI WR1804b, isotype).
Notes – Among the few species of Laboulbenia with the inner margin totally united with the receptacle but disjointed from the insertion cell, the most similar species to our collection (CAMB WR1804a) is L. schizogenii Thaxt., which was described on insects of the family Carabidae subfamily Scaritinae from USA and more recently reported from South America and West Africa (Thaxter 1896; Rossi and Leonardi 2018). However, our collection differs from Laboulbenia schizogenii by having more numerous branches of the appendages, for the thinner insertion cell, for the perithecial tip not strongly contracted above the venter, and for cell IV not prominent below the insertion cell (Fig. 1). Therefore, we introduce this collection (CAMB WR1804a) as Laboulbenia clavulata sp. nov. A picture of Laboulbenia clavulata has been already published (as Laboulbenia n. sp.) in VignaTaglianti and Rossi 1999.
Figure 1 –Laboulbenia clavulata (CAMB WR1804a, holotype). a Thallus from the type slide, from the elytra of the host-insect. b Thallus from the isotype slide (FI WR1804b), from the abdomen of the host-insect. Scale bars=50 µm