Modicella guangxiensis T. Bau & G. F. Mou, 2024

Mou, Guang-Fu & Bau, Tolgor, 2024, Modicella guangxiensis (Mortierellomycota, Mortierellaceae), a new species from south-western karst areas of China, Biodiversity Data Journal 12, pp. 115044-115044 : 115044

Modicella guangxiensis T. Bau & G. F. Mou sp. nov.

Materials

Type status: Holotype. Occurrence: occurrenceID: 4499BC04-583D-535F-A55A-331F2F84111A; Taxon: kingdom: Fungi; phylum: Mortierellomycota; class: Mortierellomycetes; order: Mortierellales; family: Mortierellaceae; genus: Modicella; taxonRank: species; Location: country: China; stateProvince: Guangxi; county: Longzhou; verbatimElevation: 191 m; verbatimLatitude: 22◦27′53.59″ N; verbatimLongitude: 106◦55′38.42″ E; Identification: identifiedBy: Guang-Fu Mou; Record Level : type: Nonggang National Nature Reserve , on soil or decomposing plant materials, 15 August 2021, Guang-fu Mou, M 2021081545 (holotype IBK!).; institutionID: IBK; collectionID: M2021081545; institutionCode: Herbarium of Guangxi Institute of Botany (IBK)

Description

Sporocarps hemispherical to nearly spherical, base flattened or flat with a cavity; 1.5-4.5 mm in diameter, 1.5-3.0 mm in height; white when fresh and becoming pale yellow when dried; fragile; surface appearing granular when fresh and containing sporangia (Fig. 1 A and B). Peridium absent. Columella absent. Basal hyphae white. Odour not recorded.

Sporangia subglobose, ellipsoid, (41)45-62(68) × (35)40-54(61) μm, hyaline, thin-walled, containing 11-15(18) sporangiospores (Fig. 1 C-F); each sporangium is attached to a single subtending hypha (Fig. 1 E). Sporangiospores subglobose, ellipsoid, ovoid or irregular, colourless, cyanophilous, with a significant oil-like content, (14)16-30(34) × (12)14-23.5(27.5) μm, 21 × 17 μm on average (Fig. 1 G and H); some sporangiospores will elongate and constrict into two sporangiospores (Fig. 1 H). There are three kinds of hyphae: hyphae of surface with hemispherical tuber (Fig. 1 I), 3 μm in diameter, not easily found; hyphae of branched (Fig. 1 J), 3-4.5 μm in diameter; hyphae linking with sporangium (Fig. 1 K), wider in width, 5.5-6.8 μm, sometimes branched. All hyphae hyaline, thin-walled or slightly thick-walled, septa rarely seen. Zygospores not observed.

Diagnosis

Differing from the known species by the number of sporangiospores per sporangia (11-18), the size of sporangiospores (14-34 × 12-27.5 μm) and the surface of some hyphae with hemispherical tuber.

Etymology

Modicella guangxiensis (Lat.): referring to the locality of the type specimen, Guangxi Zhuang Autonomous Region of China.

Distribution

So far, only known from Guangxi (CHINA).

Ecology

It grows on broad-leaved forest soil or decomposing plant materials of karst areas.

Figures

Figure 1. Morphology of Modicella guangxiensis. A Sporocarps and its habitat; B Dried yellowish sporocarps; C-F Intact sporangia; G, H Sporangiospores; I, J, K Different kinds of hyphae. Scale bar A-B = 5 mm; C-F = 25 μm; G-H = 20 μm; I-K = 10 μm. C, D, G, I. in purified water; E, J, K. in 1 % Congo Red; F, H. in Cotton Blue; Photos by Guang-fu Mou, from M 2021081545 (holotype IBK!).