Chlorociboria subtilis P.R.Johnst., 2021

Johnston, Peter R., Park, Duckchul, Smith, Matthew E., Mujic, Alija B. & May, Tom W., 2021, Brahmaculus gen. nov. (Leotiomycetes, Chlorociboriaceae), MycoKeys 80, pp. 19-43 : 19

Chlorociboria subtilis P.R.Johnst. sp. nov. Figure 9

Typification.

New Zealand - Westland • Haast Pass Summit, Lookout Track; -44.1063, 169.3519; on fallen leaves Dracophyllum sp.; P.R. Johnston (D2515), M. Padamsee leg.; 16 May 2018; PDD 112247 - holotype.

Etymology.

From Chlorociboria subtilis (delicate) referring to the stature of the apothecia.

Diagnosis.

Blue-green apothecia on blue-green stained fallen, partly decomposed leaves, hairs on receptacle rough-walled, somewhat flexuous, ascospores filiform, 45-55 × 1 µm.

Description.

Apothecia erumpent from blue-green stained leaf tissue. Apothecia less than 1 mm diam., cupulate with short, broad stipe, receptacle pale blue-green with tangled, white hairs, especially near the edge of the cup. Hairs 55-75 × 3-4 µm, somewhat flexuous, wall roughened. Apothecia in vertical section with ectal excipulum up to 30 µm wide, cells 6-10 µm diam., short-cylindric to square, walls thick, cells arranged in rows with a high angle to the receptacle surface; medullary excipulum poorly developed, two or three rows of narrow-cylindric cells, walls encrusted with blue-green material; stipe with thick-walled textura intricata. Paraphyses 1.5-2 µm diam., slightly wider towards the apex, often branched in the upper 20-30 µm, extending 15 µm beyond asci. Asci 85-105 µm × 5.5-6.5 µm cylindric, tapering gradually to small, truncate apex, wall thickened at apex, amyloid pore in inner half of wall, reaction most intense on inner edge of wall, pore appears more or less U-shaped, sloping outwards slightly through the wall, 8-spored, spores confined to the upper 60-100 µm of ascus, crozier present. Ascospores 45-55 × 1 µm, filiform, straight, 0-septate, hyaline.

Additional specimens examined.

New Zealand - Nelson • Arthur Range, Graham River Valley Rd , track from Flora car park to Mt Arthur Hut ; on Dracophyllum pyrimidale fallen leaves; P.R. Johnston (D990) leg.; 6 May 1994; PDD 105292 - Central Otago •vic. Dunedin, Great Moss Swamp ; on Dracophyllum uniflorum fallen leaves; P.R. Johnston (D82) leg.; 12 May 1984; PDD 105293 - Mid Canterbury • Craigieburn, Cave Stream; on Dracophyllum uniflorum fallen leaves; P.R. Johnston (D248) leg.; 23 Feb 1988; PDD 105294 - Taupo • Tongariro National Park , Ohakune Mountain Road , Blyth Track ; on Fuscopora cliffortioides fallen leaves; P.R. Johnston (D353) leg.; 20 May 1989; PDD 55523 • Rangitoto Station , Ranginui Summit; on Dracophyllum pyrimidale fallen leaves; P.R. Johnston (D1622), S.R. Whitton leg.; 6 May 2001; PDD 117584 .

Notes.

Most specimens are on fallen leaves of Dracophyllum spp., but the host range may be more extensive. A specimen on Fuscopora cliffortioides (PDD 55523) is morphologically similar, but perhaps with longer ascospores.

Figures

Figure 9. Chlorociboria subtilus (PDD 112247) A dried apothecium B apothecium in vertical section C detail of margin of receptacle in vertical section D asci, ascospores and paraphyses E detail of apex of paraphyses and asci F excipular hairs (squash mount). Scale bars: 0.1 mm (A); 100 µm (B); 10 µm (C-F).