Erioscyphella insulae Tochihara & Hosoya, 2022

Tochihara, Yukito & Hosoya, Tsuyoshi, 2022, Examination of the generic concept and species boundaries of the genus Erioscyphella (Lachnaceae, Helotiales, Ascomycota) with the proposal of new species and new combinations based on the Japanese materials, MycoKeys 87, pp. 1-52 : 1

Erioscyphella insulae Tochihara & Hosoya sp. nov.

Figs 7 , 8

Diagnosis.

Characterized by pure white apothecia unlike related species Lachnum nothofagi , and two-layered ectal excipulum.

Holotype.

Japan, Okinawa, Yaeyama, Taketomi, Iriomote Island, Otomi, 24.297458, 123.866128, ca 50 m, 12 Jun. 2011, on fallen bark of unidentified tree, T.Fukiharu (TNS-F-39720).

GenBank/UNITE no. ex holotype.

LC669451/UDB0779063 (ITS), LC533177 (LSU), LC533261 (mtSSU), LC533207 (RPB2).

Other specimens examined.

Japan, Bonin Islands , Hahajima Island, Sekimon, 26.666686, 142.152222, ca 260 m, 24 Jun. 2009, on fallen bark of unidentified tree, T.Hosoya (TNS-F-26485, 26500) .

Etymology.

Referring to the occurrence of the species on remote islands in Japan.

Japanese name.

Shima-hina-no-chawantake.

Description.

Apothecia gregarious, superficial, 0.7-1.4(-2.5) mm in diameter, short- and thick-stipitate, up to 0.8 mm high, externally white to cream throughout but sometimes pale brown in the lower parts, covered with white hairs. Disc concave, cream to pale yellow (fresh state not observed). Ectal excipulum composed of two layers: outer layer textura angularis, up to 20 µm thick, 3-28 × 2-8 µm, hyaline, thin to relatively thick-walled, with cell walls smooth; inner layer up to 15 µm thick, textura porrecta composed of hyaline hyphae up to 5 µm wide. Medullary excipulum up to 100 µm thick, composed of hyaline hyphae forming textura intricata; hyphae up to 3 µm wide. Hairs straight or irregularly curved, cylindrical, sometimes branched, up to 125 × 2.5-3.0 µm, hyaline, completely granulate, thin-walled; lacking crystals or resinous materials; apex usually equipped with hyaline apical amorphous materials. Asci (88-)92-101(-106) × 6-7.3(-8) µm (av. 96 ± 4.5 × 6.7 ± 0.6 µm, n = 18), 8-spored, thick-walled, cylindrical-clavate, arising from ascogenous hyphae branching several times; pore blue in MLZ without 3% KOH pretreatment; croziers absent at the basal septa. Ascospores (24-)26.7-34.5(-39) × (1.8-)1.9-2.3(-2.5) µm (av. 31 ± 3.9 × 2.1 ± 0.2 µm, n = 18), Q = (11-)12.5-17(-20) (av. 14.7 ± 2.3, n = 18), showing various shapes and lengths, usually long fusiform and sometimes hypsiloid or sigmoid due to bending of both ends, sometimes swelling or constricted irregularly, aseptate or one- to three-septate (usually one-septate). Paraphyses straight, narrowly lanceolate, up to 2.5 µm wide, septate, exceeding the asci up to 7.5 µm.

Culture characteristics.

Colony of NBRC 114445/ TNS-F-26500 and NBRC 114459/ TNS-F-39720 on PDA relatively thick-planar, pruinose, white to cream, ivory at the margin, pale sepia. Sectors and zonation absent. Aerial mycelium white to pale ocher, mainly developed except in the margin, not forming mycelial strands. Soluble pigment amber colored produced at the center. Margin unclear, flat and immersed into agar, radially undulate. Anamorph not seen.

Distribution.

Japan (Bonin Islands, Yaeyama Islands).

Notes.

This fungus resembles Lachnum nothofagi (Dennis) Spooner in the size and shape of apothecia, ascospores, asci, and hairs. However, E. insulae has completely hyaline hairs and ectal excipulum, and hairs are equipped with apical materials (Fig. 7J , 8A ), whereas L. nothofagi has partly to totally brown hairs and ectal excipulum ( Spooner 1987). Lachnum nothofagi is currently known only from New Zealand and Australia and mainly arises from Nothofagus spp., which are native in the southern hemisphere ( Spooner 1987).

Figures

Figure 7. Erioscyphella insulae TNS-F- 39720 (Holotype) A dried apothecia B a pure culture on PDA (NBRC 114459) C asci D ascal pore MLZ (+) E ascospores F ascogenous hyphae G paraphyses H layer structures of excipulum H 1 medullary excipulum H 2 inner layer of ectal excipulum composed of hyphae H 3 outer layer of ectal excipulum composed of textura angularis I, J hairs with apical amorphous materials. Mounted in CB / LA (C, E-J), MLZ (D). Scale bars: 1 mm (A); 10 µm (A-J).

Figure 8. Erioscyphella insulae TNS-F- 39720 (Holotype) A expansion of a vertical section of an apothecium B ascospores C apothecium D vertical section of an apothecium E asci F paraphyses G layer structures of excipulum.