Umbelopsis hingganensis Tong Wu, T. Du, M. M. Ding & L.J. Xu, sp. nov.

Index Fungorum number: IF 902418; Mycobank number: MB 902418; Facesoffungi number: FoF 16073; Fig. 1

Etymology – Referring to the location where the type material was collected.

Holotype – HMPHU 1269A.

Saprobic on fallen dead leaves. Sexual morph Not observed. Asexual morph Sporangiophores arising from a vesicle, verticillately, simply branched, hyaline, 26.8–76.6 μm long, 2.1–4.2 μm wide. Sporangia globose to subglobose, 7.1–11.8 μm in diameter, reddish brown to reddish purple when mature, multi-spored. Sporangiospores irregularly angular, (2.4–) 3.5–3.7 (−6.1)×(1.9–) 2.7–2.8 (−3.6) μm, reddish brown to reddish purple, without oil droplet. Columellae absent or slightly convex. Collars absent. Chlamydospores globose to subglobose, single or bunching, 5.3–14.8 μm in diameter, containing abundant oil droplets.

Culture characteristics – Colonies growing on PDA, cottony, at first white for the hyaline hyphae and when old pinkish due to the occurrence of pigmented sporangia, reaching 30–32 mm in 14 days at 25 °C. Colonies growing on OA, velutinous, yellowish white, reaching 9–11 mm in 14 days at 25 °C. Colonies growing on CMA, flat, hairy or cottony, at first white for the hyaline hyphae and when old reddish purple due to the occurrence of pigmented sporangia, reaching 36–38 mm in 14 days at 25 °C.
Material examined: China, Heilongjiang Province, Greater Hinggan Mountains, on fallen dead leaves of Larix gmelinii, September 2018, Zeyu Li and Zhedong Zhang (HMPHU 1269A, holotype), ex-type CCTCC AF 2022084.

GenBank numbers – ITS=OM838288, LSU=OM838391, SSU=OQ147016.

Notes – Umbelopsis hingganensis differs from its closely related species in that it has reddish brown to reddish purple, globose, 7.1–11.8 μm diameter sporangia and angular sporangiospores. Umbelopsis hingganensis and the other three closely related species U. isabelline, U. ovata, and U. autotrophica formed a monophyletic group with 90% ML and 1.00 BYPP support based on the phylogenetic analysis on their ITS, LSU and SSU sequences. Umbelopsis isabelline and U. autotrophica differ by having globose sporangiospores from U. hingganensis (Bezerra et al. 2018; Meyer and Gams 2003). Umbelopsis ovata differ differs from U. hingganensis fusiform sporangia (Yip 1986).

Figure 1 – Umbelopsis hingganensis (CCTCC AF 2022084, holotype). a–c Upper view and reverse view of colony on PDA (a), OA (b), and CMA (c). d–h Sporangia. i Sporangiospores. Scale bar: d, e=100 μm, f–i=10 μm