Laboulbenia bifida W. Rossi & M. Leonardi, sp. nov.
Index Fungorum number: IF 559786; Mycobank number: MB 559786; Facesoffungi number: FoF 12925; Fig. 1
Etymology – From Latin bifidus =bifid, divided in two parts, referring to the outer appendage consisting of two subequal branches.
Holotype – FI WR3571.
Basal cell (cell I) grayish yellow, relatively small, about twice longer than maximum width, tapering below. Suprabasal cell (II) paler and much larger than the former, dirty yellow, almost twice longer than broad, slightly enlarging upwards. Cell III much smaller than cell II, bicolored, with the lower portion concolorous with the underlying cell and the upper grayish yellow, distinctly darker. Cell IV as long as cell III but slightly wider, dark gray, becoming paler on the inner side. Cell V small, shield-shaped and yellowish. Insertion cell black and thick. Outer appendage consisting of a dirty yellow, relatively large, broader than long and irregularly quadrangular basal cell, bearing distally two simple and elongate branches. The latter are similar except in color, the outer one being darker in the lower portion, with the two lowermost cells dark gray, the third light gray, the others dirty yellow. Cell VI quadrangular, distinctly shorter than the flanking cell III. Perithecium more than half free, about two and a half times longer than broad, irregularly yellowish gray, darker above its basal cells, not abruptly tapering to the tip, ending in a hyaline and subtruncate apex pointing outwards, subtended by a blackish area more extended on the ventral side and darker on the dorsal. Length from foot to perithecial apex 325–425 µm; longest appendage 275 µm; perithecium 175–195×65–75 µm.
Material examined – New Zealand, South Island, mouth of Taieri River, under driftwood, sandy beach, January 2007, J. Nunn, on various parts of the body of Otagonia chathamensis Bordoni (Coleoptera, Staphylinidae), FI WR3571 (holotype).
Notes – Although Laboulbenia, with almost 700 species, is by far the largest genus among the Laboulbeniales, the species of this genus occurring on Staphylinidae are just over thirty. None of these fungi bear an outer appendage consisting of two subequal branches arising from the basal cell, which makes Laboulbenia. bifida distinguishable at first sight. The new species might be compared only with L. micrandra, with which it shares a bifurcate outer appendage, an inner appendage lacking sterile branches, and a septum between cells IV and V not reaching cell III. However, the latter species, parasitic on Lobrathium sp. from Ecuador, is distinctly smaller and slenderer, with the outer appendage dividing above the second cell (not above the first, as in Laboulbenia bifida), and with very different perithecial tip and apex (Rossi 2011).
Figure 1 – Laboulbenia bifida (FI WR3571, holotype). Scale bars:100 µm