Paragaeumannomyces elegans Reblova & A.N. Mill., 2020

Reblova, Martina, Nekvindova, Jana, Fournier, Jacques & Miller, Andrew N., 2020, Delimitation, new species and teleomorph-anamorph relationships in Codinaea, Dendrophoma, Paragaeumannomyces and Striatosphaeria (Chaetosphaeriaceae), MycoKeys 74, pp. 17-74 : 17

Paragaeumannomyces elegans Reblova & A.N. Mill. sp. nov. Figure 6

Typification.

New Zealand - West Coast • Westland District, Mount Aspiring National Park, Haast, Roaring Billy track; 22 Mar. 2005; on decaying wood; M. Réblová leg.; M.R. 3295/NZ 566A (holotype: PDD 118740!).

Etymology.

Elegans (L) elegant, referring to elegant and lovely ascomata adorned with setae.

Description on the natural substrate.

Teleomorph: Ascomata perithecial, non-stromatic, superficial, in small groups, often gregarious, 290-350 μm diam, 280-350 μm high, subglobose to slightly conical, dully glossy, brown with a light grey tinge except for the tiny black papilla composed of thick-walled, dark brown cells, ascomata densely setose, setae 28-60 × 4.5-6 μm, stiff, acute, dark brown, thick-walled, opaque. Ostiole periphysate. Ascomatal wall leathery, three-layered. Outer layer of textura angularis, 33-41 μm thick, consisting of thin-walled, globose to subglobose to polyhedral, reddish-brown cells ca. 5-12 μm diam. Middle layer of textura prismatica, 9.5-18 μm thick, composed of thick-walled, polyhedral, elongated, dark brown, melanised cells. Inner layer of textura prismatica, 5-8 μm thick, composed of thin-walled, flattened and elongated hyaline cells. Paraphyses abundant, hyaline, sparsely branched, septate, 3.5-5 μm wide, tapering to ca. 2 μm, longer than the asci. Asci (152-)174-221(-227) × 10.5-15(-20) μm (mean ± SD = 204.8 ± 13.7 × 12.3 ± 1.5 μm), (129-)141-197(-204) μm (mean ± SD = 168.2 ± 17.2 μm) long in the sporiferous part, cylindrical-fusiform, stipitate, apically rounded, ascal apex non-amyloid with a distinct apical annulus 2.5-3 μm wide, 2-2.5 μm high. Ascospores (57.5-)60-73(-75) × (3.5-)4-4.5(-5) μm (mean ± SD = 65.5 ± 3.2 × 4.1 ± 0.2 μm), filiform to cylindrical, straight or slightly curved to sigmoid, hyaline, with negative or very weak dextrinoid reaction in Melzer’s reagent, 7-septate, septa usually obscured by large guttules, not constricted at the septa, asymmetrical, rounded at the apical end, slightly tapering towards the basal end, with one or two guttules in each cell, 2-3-seriate or 3-4-seriate, partially overlapping. Anamorph: Unknown.

Other specimen examined.

New Zealand - Otago • Clutha District, The Catlins, Catlins Coastal Rain Forest Park, MacLennan Range, Lake Wilkie Walk; 17 Mar. 2005; on decaying wood of a branch; M. Réblová leg.; M.R. 3289/NZ 549 (PDD 118742). - West Coast • Westland District, Ship Creek Point, Kahikatea Swamp Forest walk; 8 Mar. 2003; on decaying wood; M. Réblová leg.; M.R. 2819/NZ 329 (PDD 118741). - West Coast • Westland District, Ross, Totara Valley Road, 12 Apr. 2005; on decaying wood; M. Réblová leg.; M.R. 3486/NZ 775 (PDD 118743).

Habitat and distribution.

The present species is a saprobe on decaying wood of Nothofagus sp. and other unidentified hosts, known from New Zealand ( Atkinson et al. 2007; this study).

Notes.

Paragaeumannomyces elegans is distinguishable from other members of the genus by densely setose, dull glistening brown ascomata with a light grey tinge, which gives them an almost grey appearance when dried. The new species resembles P. garethjonesii ( Perera et al. 2016) and P. panamensis ( Huhndorf and Fernández 2005) in 7-septate ascospores and setose ascomata with acute, stiff, opaque setae scattered over the entire surface, but differs from them in larger ascomata, asci and wider ascospores (for a detailed comparison see the key).

Comparison of the ITS sequence of the holotype of P. elegans with available Paragaeumannomyces sequences revealed 100 % sequence similarity with a specimen PDD 92561 (New Zealand, Taupo, Ohakune, ITS: EUO37895) tentatively identified as P. raciborskii ( Atkinson et al. 2007) (Fig. 2 ).

Figures

Figure 2. Combined phylogeny using ITS and 28 S of 35 members of Paragaeumannomyces. Species names given in bold are new species; T and PT indicate ex-type and ex-paratype strains. Thickened branches indicate branch support with MLBS = 100 %, PP values = 1.0 and MP = 100 %. Branch support of nodes ≥ 75 % ML and MPBS, and ≥ 0.95 PP is indicated above branches.

Figure 6. Paragaeumannomyces elegans. A, B ascomata C vertical section of ascomal wall D ascal apex with apical annulus E-G asci H ascospores I paraphyses. Images: PDD 118740 (A, B, D, H, I); PDD 118741 (C, E-G). Scale bars: 250 μm (A, B); 20 μm (C); 10 μm (D-I).