Euphoriomyces Thaxt.

Santamaria, Sergi & Pedersen, Jan, 2021, Laboulbeniomycetes (Fungi, Ascomycota) of Denmark, European Journal of Taxonomy 781, pp. 1-425 : 52-53

Genus Euphoriomyces Thaxt.

MB#1935

Memoirs of the American Academy of Arts and Sciences 16: 307 ( Thaxter 1931). –

Type species: E. bilateralis Thaxt.

Brief description

Monoecious or dioecious. Receptacle consisting of a multicellular axis extending into the primary appendage; some of the cells below the perithecium divide laterally by means of vertical septa.Antheridia terminal on any part of receptacle or appendages.

Remarks

With the two new species described here, the genus consists of 19 species, of which 10 in Europe, eight in Denmark. The most recently described species is Euphoriomyces rugosus ( Rossi & Bernardi 2018) . Eleven species occur on Col. Leiodidae . The genus was reviewed by Santamaria (1991). The genus Euphoriomyces belongs to the tribe Euphoriomyceteae I.I.Tav. ( Tavares 1985) , together with genera Phaulomyces and Siemaszkoa , well-characterized because the walls of the perithecial basal cells and cell VII almost vanish with maturity, being hardly distinguishable. Another particular character of the tribe refers to the number of perithecial wall cells in each vertical row, with three in three of the rows and four in the remaining, where the extra 4 th cell is visible as a small protruding cell near the perithecial apex ( Fig. 9C, w 4 ).

Key to the Danish species (partially following Majewski 1994b and Santamaria 2003)

1. Perithecia ovate. Receptacle cells below perithecia divided laterally to form unicellular or multicellular secondary appendages. Sometimes, thalli appearing flattened on the host body surface (similar to Rickia species ) .................................................................................................................................. 2

– Perithecia slender. Receptacle cells below perithecia not or rarely laterally divided. Thalli not flattened. On Col. Staphylinidae .................................................................................. E. huggertii T.Majewski

2. Perithecial neck inconspicuous. Perithecial basal cells (m, n, n’) and secondary stalk cell (VII) fully indistinguishable in mature thalli. On Col. Leiodidae ...................................................................... 3

– Perithecial neck conspicuous, abruptly distinguished. Trichogyne scar persistent as an outgrowth. Some of the perithecial basal cells and secondary stalk cell (VII) ± visible at maturity. On Col. Ptiliidae of the genus Smicrus Matthews, 1872 ...................................................... E. smicri Santam. sp. nov.

3. One of the upper axial cells next to the perithecium distinctly elongate. Cell VI triangular in section, forming a strongly oblique base for perithecium. On Col. Leiodidae of the genus Hydnobius Schmidt, 1841 ....................................................................................................... E. magnicellulatus Santam.

– All cells of receptacle similar each other or cell VI different........................................................... 4

4. Thalli without long branches (i.e., secondary appendages) below the perithecia (rarely one such appendages in E. unilateralis just below the lowermost perithecium)............................................. 5

– Thalli with few to many long branches (i.e., secondary appendages) below or between the perithecia........................................................................................................................................... 6

5. Thalli very small, up to 85 µm from foot to perithecial tip; with a receptacle consisting of 3–6 superposed cells. Typically on Cyrtusa Erichson, 1842 and Colenis Erichson, 1842 (Col. Leiodidae ) ........................................................................................ E. gillerforsii (Huggert) I.I.Tav.

– Thalli measuring more than 85 µm from foot to perithecial tip, with a receptacle consisting of 8–12 superposed cells. On Agathidium Panzer, 1797 (Col. Leiodidae ) .. E. unilateralis T.Majewski

6. Secondary appendages ± darkened, with the upper ones remarkably longer and darker. On Leiodes rugosa (Col. Leiodidae )........................................................................ E. enghoffii Santam. sp. nov.

– Secondary appendages entirely hyaline............................................................................................ 7

7. Thallus flattened like a sheet, consisting of several superposed tiers of few to several cells separated from each other by vertical septa. All perithecia developing from the same side of the thallus; antheridia and the variably elongated secondary appendages present in both margins of the receptacle. On Leiodes Latreille, 1797 (Col. Leiodidae ) .................................... E. liodivorus (Huggert) I.I.Tav.

– Characters not as above. On Agathidium , Amphicyllis Erichson, 1845 and Cyrtusa (Col. Leiodidae )............................................................................................... E. agathidii (Maire) I.I.Tav.

Figures

Fig. 9. Euphoriomyces spp. A–C. E. gillerforsii (Huggert) I.I.Tav. A–B. Paired mature thalli, with unicellular secondary appendage labelled in B (sa). C. Detail of perithecial apex with labelled extra cell w 4. – D–E. E. huggertii T.Majewski. D. Mature thallus with labelled primary appendage (pa). E. Paired mature thalli. – F–G. E. liodivorus (Huggert) I.I.Tav. Mature thalli. Scale bars: A–C = 20 µm; D–G = 50 µm. Photographs from slides ZMUC C-F-124079 (A–C), ZMUC C-F-123294 (D–E), ZMUC C-F- 124158 (F), and ZMUC C-F-124138 (G).

Fig. 4. A–D. Euzodiomyces lathrobii Thaxt. A–B. Reduced forms. C. Typical form. D. Labelling of a secondary axis, with antheridia (an) and perithecial initial with cell VII. – E. Zodiomyces vorticellarius Thaxt.; with labelled cell I and buffer projections (bf). – F. Coreomyces arcuatus Thaxt.; mature thallus. – G. Coreomyces corixae Thaxt.; mature thallus showing the appendiculate cells (ac). – H. Coreomyces macropus Thaxt.; mature thallus. Scale bars: A–C, E–H = 50 µm; D = 25 µm. Photographs from slides ZMUC C-F-123138 (A–B), ZMUC C-F-124066 (C), ZMUC C-F-122479 (D), ZMUC C-F-122570 (E), ZMUC C-F-124285 (F), ZMUC C-F-123723 (G), and ZMUC C-F-123722 (H).