Erioscyphella boninensis 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 boninensis Tochihara & Hosoya sp. nov.

Figs 5 , 6

Diagnosis.

Differs from all other Erioscyphella species by the granulate walls of the ectal excipular cells.

Holotype.

Japan, Bonin Islands, Chichijima Island, Mt. Tsutsujiyama, 27.060556, 142.222500, ca 270 m, 28 Jun. 2009, on fallen leaves of Pittosporum boninense , T.Hosoya (TNS-F-26520).

GenBank/UNITE no. ex holotype.

LC669437/UDB0779049 (ITS), LC533151 (LSU), LC533254 (mtSSU), LC533196 (RPB2).

Etymology.

Referring to the type locality Bonin Islands.

Japanese name.

Ogasawara-cha-hina-no-chawantake.

Description.

Apothecia scattered, superficial, 0.5-1.0 mm in diameter, having well-developed stipes, up to 1.5 mm high, cream to pale brown, externally covered with short and shiny hairs. Disc concave, cream to pale yellow. Ectal excipulum textura prismatica composed of long elongated cells to textura angularis, 6-25 × 5-13 µm, hyaline to relatively brown colored, somewhat thick-walled; cell walls covered by granules with a similar appearance to those on hairs. Stipe composed of textura prismatica with a granulate surface as ectal excipular cells. Medullary excipulum textura intricata of hyaline hyphae up to 3 µm wide. Hairs straight, cylindrical, 38-62 × 2.5-4.0 µm, hyaline, completely covered by brown granules, 2-3-septate, thin-walled, arising from swelling cells completely covered by granules; apex lacking crystals or apical amorphous materials, equipped with amber-colored resinous materials dissolvable with CB/LA at a little below the apex. Asci (36-)37.7-44(-46) × (3.5-)3.6-4.2(-4.5) µm (av. 41 ± 3.2 × 3.9 ± 0.3 µm, n = 16), 8-spored, cylindrical-clavate; pore blue in MLZ without 3% KOH pretreatment; croziers absent at the basal septa. Ascospores (9-)10-12.3(-13) × 1.2-1.7(-1.8) µm (av. 11 ± 1.2 × 1.5 ± 0.2 µm, n = 16), Q = (6.3-)6.9-9.2(-10) (av. 7.8 ± 1.5, n = 16), fusiform, aseptate. Paraphyses straight, up to 2.5 µm wide, septate, exceeding the asci up to 5 µm, narrowly lanceolate.

Culture characteristics.

Colony of NBRC 114447/ TNS-F-26520 on PDA umbonate forming a dome-shape, slightly sulcate. Context not shiny, velvety, buff at the center, paler toward the margin, dark buff from the reverse. Sectors and zonation absent. Aerial mycelium white or buff, dense cottony, forming white mycelium strands except in the margin. Margin distinct, entire, flat. Asexual morph absent.

Distribution.

Japan. (Bonin Islands). Known only from the type locality.

Notes.

Granulation on the surface of the ectal excipular cells has been observed only in Incrucipulum in Lachnaceae ( Baral and Krieglsteiner 1985; Tochihara and Hosoya 2019), and E. boninensis is the first report for such a character in Erioscyphella (Fig. 5H , 6E ). Phylogenetic analysis revealed that E. boninensis is closely related to E. paralushanensis (Fig. 1 ). The two species (Clade IA, Fig. 1 ) have colored granules on hairs and forming red mycelia on PDA. However, granulation of ectal excipulum is seen only in E. boninensis .

Figures

Figure 1. ML best-scored phylogenetic tree based on the concatenated dataset of ITS, LSU, mtSSU, and RPB 2 constructed using RAxML-NG. MLBP / MPBP / BPP are represented on branches in this order. In MLBP / MPBP <50 % or BPP <0.95, a hyphen appears. No evaluation values are shown on branches when MLBP and MPBP <50 % and BPP <0.95. The branch of a clade TNS-F- 17245 + 17249 to its most recent common ancestor is only one-third of the intended length due to space limitation.

Figure 5. Erioscyphella boninensis TNS-F- 26520 (Holotype) A dried apothecia B pure culture on PDA (NBRC 114447) C ascus D ascal pore MLZ (+) E ascospores F paraphyses G ectal excipular cells H ectal excipular cells with red granules I hairs with resinous matters arising from ectal excipular cells. Mounted in CB / LA (C, E-I), MLZ (D). Scale bars: 1 mm (A); 10 µm (C-I).

Figure 6. Erioscyphella boninensis TNS-F- 26520 (Holotype) A ascospores B apothecium C vertical section of an apothecium D expansion of a vertical section of an apothecium E ectal excipular cells F asci G paraphyses H hairs.