Chaenothecopsis nodosa Beimforde, Tuovila, Rikkinen & 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 nodosa Beimforde, Tuovila, Rikkinen & A.R. Schmidt sp. nov.

Figs 8 , 9 , 10

Type.

New Zealand, North Island, close to Kakaho Camp site, central North Island , ca. 38°34.0224'S, 175°43.0525'E, on exudate of Prumnopitys taxifolia , 5 April 2015, Beimforde PDD 110745, holotype ; New Zealand Fungarium (PDD), Landcare Research in Auckland, GenBank accession OQ308934 / OQ308877 .

Diagnosis.

Chaenothecopsis nodosa differs from other Chaenothecopsis species by producing capitula in a catenulate stack, consecutively on top of each other, typically covered with a white pruina.

Etymology.

The specific epithet refers to the appearance of catenulate groups of sphaeric capitula stacked on top of each other

Description.

Apothecia growing on the exudate of Prumnopitys taxifolia , 1.0-3.1 mm tall, growing individually and proliferating from the capitulum, often several from a single capitulum or from the stipe, eventually forming catenulate stacks of several capitula on top of each other. Stipe dark brown to black, straight to slightly curved, 100-190 μm wide, becoming crustose with age, often with a white pruina at upper stipe regions, and sometimes with an additional red pruina below. Stipe hyphae 3-8 µm wide, with walls two layered, the outer wall dark brown, 1.5-3.5 µm and with cell walls fused in most parts, the inner wall c. 0.5-1 µm, with the hyphae intertwined (textura prismatica-intricata), swelling in KOH; hyphae in inner parts yellowish to light brown, 2-5 µm wide, swelling in KOH. Capitulum black, lenticular to almost spherical or ellipsoid, 150-420 μm wide, 250-220µm high; typically a white pruina is macroscopically visible on the capitula. Excipulum hyphae light brown to hyaline in younger ascomata, brown in older ascomata, 2-6 µm wide, intertwined (textura prismatica-intricata), swelling in KOH; often covered with a crusty layer of amorphous material and crystals. Epithecium light green to moss green, appearing as a crusty layer, variously (up to 20 µm) thickened, usually with crystals, composed of hyphae extending from the excipulum; hyphae attached to the hymenium by the amorphous material. Hymenium light brown to olive green, with the hyphae swelling in KOH, full of amorphous material strongly congealing the asci and paraphyses together. Paraphyses hyaline, filiform, 1.5-2.5 μm wide (n = 20), sometimes branched, as long as or slightly longer than asci, variously covered with amorphous material, septate at 10-25 μm intervals, with the apices intertwined and agglutinated with the hyphae of the epithecium. Asci cylindrical, 60-77 × 4.9-7.7 μm (n = 8), with the apex variously thickened, penetrated by a minute canal visible only in young asci; mature asci usually without a thickening, variously covered with light green to hyaline, amorphous material, formed with croziers; asci in older capitula disintegrated. Ascospores uniseriate, obliquely to periclinally oriented in the asci, 1-septate, brown, cylindrical to slightly ellipsoid, ornamented, (6.7-) 8.5-9.2 (-10.8) × (3.1-) 3.4-3.9 (-4.6) μm (n = 60) [mean 9.5 × 3.8 μm, Q = (2.8-) 3.5-4.6 (-5.4), mean Q = 3.8]; septa as thick as spore wall.

Ecology and distribution.

Chaenothecopsis nodosa has to date been found only in temperate broad-leaved rainforests of New Zealand on semi-hardened exudate and exudate-soaked exposed wood and bark on the main trunk of Prumnopitys taxifolia .

Specimens examined.

Specimens PDD 110743 and PDD 110745 (Figs 8 , 9 ) on exudate of Prumnopitys taxifolia . The specimens are deposited in the New Zealand Fungarium (PDD), Landcare Research, Auckland. The collection data and GenBank accession numbers are given in Suppl. material 1.

Figures

Figure 8. Light micrographs of Chaenothecopsis nodosa sp. nov. (PDD 110745) A branched ascoma with catenulate capitulum B development of this ascoma has involved at least 11 separate stages of capitulum proliferation C detail of compound capitulum D ascospores. Scale bars: 100 µm (A, B, D); 10 µm (C).

Figure 9. Scanning electron micrographs of Chaenothecopsis nodosa sp. nov. (PDD 110745) A branched ascoma with numerous tightly stacked capitula B cross section of stipe C ascospore ornamentation D compound capitula E-G details of capitulum surface E ascospores on capitulum surface F amorphous material on capitulum surface G crystals on capitulum surface. Scale bars: 100 µm (A, D); 10 µm (B, E); 1 µm (C, F, G).

Figure 10. Anatomical details of Chaenothecopsis nodosa sp. nov. A ascospores B ascus tips C hypha of epithecium covered with amorphous material D excipulum structure E stipe hyphae F structure of the hyphae at the base of the stipe G asci with croziers H paraphyses I tips of paraphyses covered with amorphous material. Scale bars: 10 µm.