Laboulbenia caprina A. Weir, M. McHugh & W. Rossi, sp. nov.

Index Fungorum number: IF 900424; MycoBank number: MB 900424; Facesoffungi number: FoF 14178; Fig. 1

Etymology – referring to the peculiar modification of the perithecial lip cells, that resemble the horns of a goat (=capra in Latin).

Thallus erect, small, compact, hyaline to light brown with dark apical region to the perithecium, insertion cell and some appendage cells. Total length 150–183 µm. Basal cell (I) mostly hyaline with thin band of pale orange brown near the foot. Cell curved and tapered towards the foot, shape variable but typically broader distally, 20–50 ×20–35 µm. Cell II hyaline to tinged with pale brown, broader than long, 13–20×28–40 µm. Cell III hyaline or infused with brown along the outer edge, quadrate, 18–23×20–30 µm. Cell IV similar to cell III in coloration, smaller, 13–23×13–20 µm. Cell V mostly hyaline, wedge-shaped, 13–18× 5–10 µm. Appendages formed above a dark, flat insertion cell with paler brown interior. Outer appendage basal cell light brown to hyaline, quadrate, 8–13 × 8–13 µm, giving way distally to a hyaline to dark brown suprabasal cell. The latter broader than long, 10–13× 8–10 µm, deeply suffused along the base and outer margin and gives rise distally to usually two, hyaline, septate, branches (longest appendage 78 µm). Inner appendage basal cell completely hyaline, quadrate, slightly smaller overall than outer appendage basal cell, 5–13×8–10 µm, giving rise to two branches, one on each side, which themselves bifurcate to form a short, compact, tuft of branchlets reaching nearly to the tip of the perithecium (longest appendage 70 µm). Perithecium stalk cell (VI) hyaline to tinged with pale brown, rectangular, 8–20×25–33 µm. Perithecium ranges from brown to hyaline, short, squat, straight or slightly inflated about the middle, 88–108×33–53 µm. Apical region largely opaque with outer margin bulging slightly beneath the two distinct, curved, and hooked lip cells.

Material examined – Indonesia, Sulawesi Utara Province, Dumoga-Bone National Park, Toraut forest, at light, II. 1985, P. M. Hammond, on the margin of the right elytron of Coptodera sp. (BM(NH) Code No. 4.67) (Coleoptera, Carabidae, Lebiini), K(M) 43521, holotype; ibid. Sulawesi Utara Province, Dumoga-Bone National Park, Plot C, el. ca. 400 m, II. 1985, P. M. Hammond, on the margin of the right elytron of Coptodera sp. (BM(NH) Code No. 4.67), AW 308 in SYR, paratype.

Notes – Fifteen mature thalli have been examined on the margin of the right elytron of Coptodera sp. This new species may be compared to a group of species viz. Laboulbenia catascopi Thaxt., L. coptoderae Thaxt., L. flagellata Peyr., and L. obliquata Thaxt. reported on Coptodera sp. collected from Central and South America (Thaxter 1896, 1908). Our collections (K(M) 43521, AW 308 in SYR) differ from each of these species in having a much shorter, more compact thallus with cell II distinctly broader than long (Fig. 1). Additionally, all of these taxa lack the very distinct hooked, lip cells at the tip of the perithecium which our collections comprise. The appendages of our collections bear some similarity with L. coptoderae, but lacking the heavy pigmentation found in both the outer and inner appendage branches. Therefore, we introduce these collections as Laboulbenia caprina sp. nov.

Figure 1 – Laboulbenia caprina (K(M) 43521, holotype). a, b Mature thalli. Scale bars: a, b=25 µm