Pseudodidymosphaeria phlei

Pseudodidymosphaeria phlei Phukhams., Camporesi & K.D. Hyde, in Li et al., Fungal Diversity 78: 10.1007/s13225-016-0366-9, [57] (2016)

Index Fungorum number: IF 551895; Facesofungi number: FoF 01816

Etymology: Names base on the host.

Saprobic on dead stem of Phleum pretense L. Sexual morph: Ascomata 200–368 μm diam. (x̄ = 290.7 μm, n = 15), solitary, scattered or gregarious on host, semi-immersed to superficial, globose to subglobose, base flattened, slightly tapering to apex, lacking ostioles. Peridium 9–24 μm wide, composed of 2–3 wall layers, outer layer of light brown to dark brown cells of textura prismatica, inner layer, 1–2 thin gelatinous layers. Hamathecium comprising numerous, long, 2–5 μm wide (x̄ = 2.5 μm, n = 50), transversely septate, branched, cellular pseudoparaphyses, embedded in a gelatinous matrix. Asci 60–100 × 10–20 μm (x̄ = 73.49 × 13.86 μm, n = 20), 8-spored, bitunicate, fissitunicate, clavate to sub-cylindrical, short pedicellate, ocular chamber clearly visible when immature. Ascospores 15–21 × 6–10 μm (x̄ = 16.8 × 7.5 μm, n = 50) bi-seriate or overlapping, ovoid to sub-oval, slightly narrow at the apex, 1-transversely septate, slightly constricted at the septa, mucilaginous sheath clearly visible, immature spores hyaline, light brown to brown when mature, smooth-walled. Asexual morph Undetermined.

            Culture characteristics: Ascospore geminating on PDA within 48 h, germ tubes developed from both ends of the ascospores. Colonies on PDA reaching 30 mm diam. after 4 weeks. Culture incubated at 16 °C, at first white, after 2 weeks pale green from center and bottom of colonies. After four weeks olive-green. Colonies morphology, umbonate, with dense mycelium, slightly papillate on the surface, circular, with dentate margin.

        Material examined: ITALY, Forlì-Cesena Province, Monte Fumaiolo – Verghereto, on a dead stem of Phleum pretense (Poaceae), 31 July 2014, E. Camporesi (MFLU 15–3281, holotype; isotype HKAS 91937), ex-type living culture, MFLUCC 14–1061, KUMCC 15–0551.

Notes: Pseudodidymosphaeria phlei is introduced from vertical dead stems of Phleum pretense L. (Poaceae). Pseudodidymosphaeria phlei is closely related to the type species, P. spartii (Fabre) Thambugala et al., as in phylogenetic analysis they form sister clades with high support values (100 % ML). Pseudodidymosphaeria phlei nevertheless is distinct in having semi-immersed to superficial ascomata, larger peridium cell walls, with 2–3 wall layers, and ascospores with less distinctly rounded ends. Therefore, we introduce Pseudodidymosphaeria phlei as a new species (Li et al. 2016).