Euphoriomyces smicri Santam., 2021

Santamaria, Sergi & Pedersen, Jan, 2021, Laboulbeniomycetes (Fungi, Ascomycota) of Denmark, European Journal of Taxonomy 781, pp. 1-425 : 61-62

Euphoriomyces smicri Santam. sp. nov.

MB#840601

Fig. 10B–F

Diagnosis

Thallus short, stout. Perithecium flask-shaped with a well-distinguished and narrow neck. Trichogyne stump remaining as an outgrowth on the outer side of the perithecium ( Fig. 10D–E , ts).

Etymology

The species epithet is based on the host genus Smicrus .

Type material

Holotype DENMARK – Nordvestsjaelland (NWZ) • Nordbredden af Skarresø ; 55°39.469′ N, 11°23.147′ E; PG47; on Smicrus filicornis (Fairmaire & Laboulbène, 1855) (Col. Ptiliidae ); 18 Feb. 2017; JP 342; JP det.; ZMUC C-F-122821 .

Isotypes DENMARK • same data as for holotype; ZMUC C-F-122822 , C-F-122823 , C-F-122824 .

Description

Thallus hyaline, except for the blackened foot and yellowish perithecium. Receptacle axis consisting of 6–10 superposed cells which are broader than long, those of the basal area being especially flattened. Basal cell of the receptacle (I) slightly longer than broad, obtriangular. Two to four of the lower cells of the receptacle remain undivided; cells above dividing at one or both sides into cells giving rise to perithecium, secondary appendages, or antheridia. The latter broad, short, stout, sessile, on any of the two sides of thallus, usually only well-distinguished on immature thalli ( Fig. 10B–C , arrows). Secondary appendages ( Fig. 10C , sa) similar to the primary appendage.

Primary appendage unbranched, continuing the main receptacle axis, consisting of up to eight elongated cells ( Fig. 10B–C , pa). The uppermost receptacular axis cell longer than broad, forming a peduncle for the primary appendage ( Fig. 10C , *). Primary septum constricted ( Fig. 10C, a ).

Perithecium solitary (only one thallus shows a second perithecial initial; Fig. 10F , arrow), flask-shaped, with a broad venter and a narrow, abruptly distinguished neck. Apex blunt to flat. Trichogyne stump apparent, resulting into an outgrowth around cell w 4 ( Fig. 10D–E , ts).

Length from foot to apex of perithecium 70–95 µm. Perithecium 40–63 × 17–27 µm. Maximum length of primary appendage from primary septum (when undamaged) 121 µm.

Thalli were found on the elytra of the hosts. The hosts were sifted from semi-dry, mouldy and rotten straw with many mice-tracks on sun-exposed grazed meadow.

Remarks

This is the first species of the genus described on a member of Ptiliidae , Smicrus filicornis , a rarely collected beetle usually found in fermenting, warm compost piles. The fungus does not seem to be related to any other known species of the genus. Although the material is scarce, we have not been able to resist describing it, given its exceptional nature. Some of the perithecial basal cells are barely apparent ( Fig. 10D ) which does not quite fit the genus description. Nevertheless, receptacle and other characteristics are seamlessly those described for the genus.

Figures

Fig. 10. Euphoriomyces spp. A. E. magnicellulatus Santam. Paired mature thalli, with elongated cell of receptacle (*). – B–F. E. smicri Santam. sp. nov. B–C. Immature thalli showing antheridia (arrows), primary appendage (pa), primary septum (a), and uppermost receptacular axial cell (*). D. Mature thallus showing cells VII, probably m (m?) and trichogyne stump (ts). E. Detail of the perithecial apex from F, with trichogyne stump (ts). F. Mature thallus with a labelled perithecial initial (arrow). Scale bars: A = 50 µm; B–D, F = 20 µm; E = 10 µm. Photographs from slides ZMUC C-F-124132 (A), and ZMUC C-F-122821 (holotype) (B–F).