Chaenothecopsis novae-zelandiae Rikkinen, Beimforde, Tuovila & A.R. Schmidt, 2023

Beimforde, Christina, Schmidt, Alexander R., Tuovila, Hanna, Kaulfuss, Uwe, Germer, Juliane, Lee, William G. & Rikkinen, Jouko, 2023, Chaenothecopsis (Mycocaliciales, Ascomycota) from exudates of endemic New Zealand Podocarpaceae, MycoKeys 95, pp. 101-129 : 101

Chaenothecopsis novae-zelandiae Rikkinen, Beimforde, Tuovila & A.R. Schmidt sp. nov.

Figs 2 , 3 , 4

Type.

New Zealand, South Island, State Highway 6 close to Makarora , Otago, ca. 44°13.787'S, 169°13.9708'E, on exudate of Prumnopitys taxifolia , 5 February 2017, holotype: PDD110744 , New Zealand Fungarium (PDD), Landcare Research in Auckland, GenBank accession OQ308936 / OQ308879 .

Diagnosis.

Chaenothecopsis novae-zelandiae differs from other Chaenothecopsis species by forming mostly solitary ascomata on podocarpous plant exudates, and by having inner ascomatal structures firmly connected by amorphous material and finely ornamented spores, which can be slightly constricted at the septum.

Etymology.

The specific epithet refers to New Zealand where the species was first discovered.

Description.

Apothecia growing on the exudate of Prumnopitys taxifolia , 0.6-1.6 mm tall, growing individually or grouped in small clusters, often branched or proliferating from the capitulum. Stipe glossy black, straight, 80-180 µm wide, sometimes slightly flexuous or curved, frequently branched at the base or, more rarely, in the upper parts. Stipe hyphae mostly covered with a layer of hard pigment partly dissolving in KOH, 6-8 µm wide, with walls two layered, the outer wall brown, 2-4 µm wide and cell walls fused, the inner wall pale to hyaline, c. 0.5-1.5 µm wide, with the hyphae intertwined (textura intricata prismatica), swelling in KOH and the yellowish brown pigment leaking into the medium; hyphae in inner part of the stipe hyaline, slightly intertwined, 3-4.6 µm, swelling in KOH. Capitulum black, in young apothecia hemispherical to sometimes almost spherical, sometimes lobed or multi-headed, 200-400 µm wide. Excipulum hyphae brownish to slightly green, 5-7 µm wide, periclinally arranged or slightly intertwined (textura prismatica), swelling in KOH, with some brown pigment leaking into the medium; wall 2-2.5 µm. Epithecium light green to emerald green, appearing as a crustose layer, usually with crystals, composed of hyphae extending from the excipulum; hyphae attached to the hymenium by the amorphous material; containing various amounts of orange to ruby-red pigment in most ascomata, usually occurring as crystals on the outer walls of hyphae, and sometimes also inside their lumina. Hypothecium light green to hyaline, with the hyphae swelling in KOH. Hymenium light brown to greenish to almost hyaline, swelling in KOH, full of amorphous material strongly congealing the asci and paraphyses together. Paraphyses hyaline, filiform, 1.5-2 µm wide (n = 10), branched, as long or slightly longer than the asci, variously covered with amorphous material, septate at 10-15 µm intervals. Asci cylindrical, 55-60 × 6.1 µm (n = 5), with the apex variously thickened, often penetrated by a short canal; mature asci usually without a thickening, variously covered with light green to hyaline, amorphous material, formed with croziers. Ascospores uniseriate, sometimes partly biseriate, obliquely to periclinally oriented in asci, 1-septate, light brown, cylindrical to slightly ellipsoid, sometimes phaseoliform, smooth, or with a very fine ornamentation, (7.7-) 8-13 (-15.4) × (2.8-) 3-3.9 (-4.5) µm (n = 70) [mean 10.3 × 3.4 µm, Q = (2.1-) 2.4-3.8 (-5.0), mean Q = 3.1]; septa as thick as the spore wall, sometimes constricted.

Ecology and distribution.

Chaenothecopsis novae-zelandiae has been found only at two locations in temperate broad-leaved rainforests of New Zealand on semi-hardened exudate and exudate-soaked bark on the main trunk of Prumnopitys taxifolia , sometimes growing mixed with Chaenothecopsis matai .

Specimens examined.

Specimens PDD110744 (Figs 2 , 3A, B, F-H ) and PDD 110742 (Figs 1A, B , 3C, D, E ) on exudate of Prumnopitys taxifolia . The specimens are deposited in the New Zealand Fungarium (PDD), Landcare Research in Auckland, with a duplicate specimen (PDD 110742/JR13033) in Helsinki (H). The collection data and GenBank accession numbers are given in Suppl. material 1.

Figures

Figure 1. Typical habitats of Chaenothecopsis species from Podocarpaceae in northern New Zealand A collecting specimens of Chaenothecopsis novae-zelandiae (PDD 110742) from a trunk of Prumnopitys taxifolia along Te Whaiti Road B (detail of A): Prumnopitys taxifolia with old, partly charred lesions C Prumnopitys taxifolia hosting Chaenothecopsis matai (PDD 110746) along Ruatahuna Road D colonized exudate of Prumnopitys taxifolia E (detail of D): exudate colonized by Chaenothecopsis matai (PDD 110746). Scale bars: 4 cm (D); 2 cm (E).

Figure 2. Light micrographs of Chaenothecopsis novae-zelandiae sp. nov. (PDD 110744). A apothecia on hardened exudate of Prumnopitys taxifolia B apothecia with proliferating capitula C ascospores. Scale bars: 200 µm (A); 100 µm (B); 5 µm (C).

Figure 3. Scanning electron micrographs of Chaenothecopsis novae-zelandiae sp. nov. (PDD 110744 / CBNZ 073 B) A proliferating apothecium B mature capitulum with ascospores and amorphous material C semi-mature capitulum D (detail of C): epithecium of semi-mature capitulum E orientation of hyphae at the base of deteriorating ascoma F stipe surface G ascospore H ascospores. Scale bars: 100 µm (A); 30 µm (B, C, E, F); 10 µm (D); 2 µm (H); 1 µm (G).

Figure 4. Anatomical details of Chaenothecopsis novae-zelandiae sp. nov. A ascospores B ascus tips C excipulum D stipe hyphae E epithecium with amorphous material and pores F hyphae of excipulum with amorphous material G asci with croziers H paraphyses. Scale bars: 10 µm.