Acervus globulosus Ekanayaka, Q. Zhao & K.D. Hyde, sp. nov., Index Fungorum number: IF552369 

Etymology: The specific epithet globulosus refers to the ectal excipulum cell type.

Holotype: CHINA, Yunnan Province, Xishuangbanna Botanical Garden, Menglun, Mengla County, N21◦55ʹ11.69ʺ, E101◦16ʹ06.87ʺ, alt. 600m, on soil near the vegetations of Millettia leptobtrya, Garcinia cowa, Castonopsis indica, 5 July 2014, W. Gang (HKAS 88987).

Diagnosis: Apothecia sessile, discoid, vivid yellow. Receptacle concave. Hymenium hyaline to yellowish. Paraphyses subcylindrical. Asci unitunicate inoperculate with 8 ellipsoid, ascospores.

Description: Saprobic on soil. Sexual morph: Apothecia 13–15 mm (x̄ =13.8 mm, n=10) diameter, arising singly or in small groups, sessile, discoid, vivid yellow (3A8) when fresh. Receptacle concave, disc and margins are yellow to orange when fresh. Hymenium hyaline to yellowish. Ectal excipulum 50–100 μm (x =68.5 μm, n=10) thick, composed of large, thin-walled, hyaline cells of textura globulosa and medullary excipulum 100–150 μm (x̄ =128.6 μm, n=10) composed of hyaline cells of textura intricata. Paraphyses 3–5 μm (x̄ =3.7 μm, n=20) wide at the middle, hyaline, aseptate, subcylindrical. Asci 72–96 × 5–6 μm (x =76.9 × 6.1 μm, n=30) (length and the width at the middle) unitunicate, inoperculate, cylindrical, long pedicellate, non-amyloid. Ascospore 5–6 × 3–5 μm (x̄ =5.8 × 4.1 μm, n=40), uniseriate, ellipsoid, 1–2 guttulate, hyaline, aseptate, smooth, thin-walled. Asexual morph: Undetermined.

Habitat and Distribution: solitary or scattered on soil with decaying litter under Millettia leptobtrya, Garcinia cowa, Castonopsis indica trees, Yunnan Province, China.

Material examined: CHINA, Yunnan Province, Xishuangbanna Botanical Garden, Menglun, Mengla County,600m alt., N21◦55ʹ11.69ʺ, E101◦16ʹ06.87ʺ, on soil near the vegetations of Millettia leptobtrya, Garcinia cowa, Castonopsis indica, 5 July 2014, W. Gang (HKAS 88987, holotype).

Notes: Acervus globulosus is distinguished by sessile, discoid, yellow apothecia with subcylindrical paraphyses and ellipsoid ascospores, and an excipulum composed of textura globulosa cells. Acervus globulosus differs from all the other species in the genus in the ectal excipulum cell type.

Fig. 1. Morphology of Acervus globulosus (holotype). a. Apothecia on soil, b. Hymenium and excipulum in vertical section, c–e.Inoperculate asci, f. Hyaline paraphyses, g. Apical apex, h–k. Hyaline ascospores. Scale bars: a=15 mm, b=100 μm, c–f=25 μm, g=12 μm, h–k=10 μm.