Erioscyphella otanii Tochihara, 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 otanii Tochihara sp. nov.

Figs 9 , 10

Diagnosis.

Characterized by pure white minute apothecia (<0.3 mm in diameter) unlike L. diminutum with rather colored apothecia, and smaller asci compared to similar species Lachnum minutum .

Holotype. Japan, Hokkaido, Horonobe, Toikambetsu, Teshio Experimental Forest, Field Science Center for Northern Biosphere, Hokkaido University, 44.993978, 142.130125, ca 400 m, 11 Jul. 2018, on fallen leaves of Sasa senanensis , Y.Tochihara & K.Kaneko (TNS-F-81472).

GenBank/UNITE no. ex holotype.

LC669471/UDB0779083 (ITS), LC533179 (LSU), LC533286 (mtSSU), LC533226 (RPB2).

Other specimen examined.

Japan, Hokkaido, Sapporo, Mt. Moiwa, 43.024718, 141.318427, ca 530 m, 21 Jun. 1965, on fallen leaves of Sasa kurilensis , Y.Otani (TNS-F-50482, in poor condition).

Etymology.

Referring to the name of Dr Yoshio Otani, the first discoverer of this species.

Japanese name.

Kita-sasaba-hina-no-chawantake.

Description.

Apothecia scattered, superficial, minute, 0.1-0.3 mm in diameter, at first spherical and later urceolate, having well-developed stipes, up to 0.3 mm high, pure white, externally covered with short white hairs, never colored brown. Disc concave, almost enclosed by an incurving margin when fresh and dry, cream to pale yellow when dry (not observed when fresh). Ectal excipulum textura prismatica like stone pavings arranged in rows, 3-25 × 3-8 µm, hyaline, relatively thick-walled; cell walls smooth. Medullary excipulum textura intricata; hyphae up to 2.5 µm wide. Hairs straight, cylindrical or tapering toward the apices, up to 60 µm long, up to 5 µm wide near the bases and 2.5-3.0 µm wide near the apices, arising from swollen ectal excipular cells, hyaline, up to 3-septate (usually 1- or 2-septate), thin-walled, completely granulated; granules dense near the apices and coarse toward the bases; apex sometimes with a hyaline and inconspicuous apical amorphous materials not dissolved with CB/LA, lacking any crystals or resinous materials. Asci (33-)34-38.8(-41) × 4-5 µm (av. 37 ± 2.2 × 4.4 ± 0.4 µm, n = 15), 8-spored, cylindrical-clavate, relatively thick-walled; pore blue in MLZ without 3% KOH pretreatment; croziers absent at the basal septa. Ascospores (11.5-)12.3-14.6(-15) × (1.2-)1.36-1.7(-1.8) µm (av. 13.4 ± 1.2 × 1.6 ± 0.2 µm, n = 15), Q = (6.7-)7.8-9.6(-10.8) (av. 8.7 ± 0.9, n = 15), fusiform, aseptate. Paraphyses straight, narrowly lanceolate to lanceolate, up to 2.5 µm wide, septate, exceeding the asci up to 10 µm.

Culture characteristics.

Colony of NBRC 114476/ TNS-F-81472 on PDA flat, partially protruding and forming mycelial mass, divided into two sectors. One sector flat, wooly to velvety, white to cream; dark ocher from the reverse. The other sector with wooly context, white and partly yellow; pale ocher from the reverse. Aerial mycelia developed throughout the colony, white, sparse to cottony, not forming mycelium strands. Margin distinct, flat and immersed into the agar. Soluble pigment absent. Asexual morph absent.

Distribution.

Japan (Hokkaido; subarctic zone).

Notes.

Erioscyphella otanii was first collected and documented by Otani (1967) under the misapplied name Dasyscyphus diminutus (TNS-F-50482). Based on the description, we concluded that the specimen was the same species as TNS-F-81472. The present species is very similar to Lachnum diminutum (Roberge ex Desm.) Rehm in the minute apothecia, ascospore size, and narrow paraphyses; however, E. otanii is pure white when fresh and dry (Fig. 9A , in dried state) and occurs on bamboo leaves, while L. diminutum is somewhat brown in the exterior parts of apothecia and occurs on sheaths of Juncus spp. ( Dennis 1949). In the mature state, the apothecia of E. otanii become urceolate (Fig. 9A and Fig. 10B ), whereas the apothecia of L. diminutum are flat ( Dennis 1949). The ITS sequence of TNS-F-81472 showed low similarity (<80%) with that of L. diminutum collected in France (GenBank accession number: MH857306). Based on the French sequence, L. diminutum is phylogenetically a good Lachnum .

The appearance of E. otanii is also similar to that of the graminicolous species Lachnum minutum W.Y. Zhuang and M. Ye documented in China ( Ye and Zhuang 2003). Erioscyphella otanii is distinguished from L. minutum in having smaller asci, although DNA sequences of the species are not available.

Figures

Figure 9. Erioscyphella otanii TNS-F- 81472 (Holotype) A dried apothecia B pure culture on PDA (NBRC 114476) C asci D ascal pore MLZ (+) E ascospore F paraphyses G a hair H hair-apex with a apical amorphous material I ectal excipular cells. Mounted in CB / LA (C, E-I), MLZ (D). Scale bars: 0.5 mm (A); 10 µm (C-I).

Figure 10. Erioscyphella otanii TNS-F- 81472 (Holotype) A ascospores B apothecium C vertical section of an apothecium D hairs with cap-like structures arising from ectal excipular cells E expansion of a vertical section of an apothecium F paraphyses G asci.