Chalarodes obpyramidata Reblova, 2021

Reblova, Martina, Nekvindova, Jana & Miller, Andrew N., 2021, Phylogeny and taxonomy of Catenularia and similar fungi with catenate conidia, MycoKeys 81, pp. 1-44 : 1

Chalarodes obpyramidata Reblova sp. nov. Fig. 8

Etymology.

Pyramidatus (L), pyramidal, prefix ob - (L), meaning reversely, inversely, referring to the conidial shape.

Type.

New Zealand - West Coast region • Westland district, Ross, Totara forest , Totara River valley ; on decaying wood of a branch; 7 Mar. 2003; M. Réblová MR 2734 / NZ 236 (holotype PDD 119363).

Description.

Colonies on natural substrate effuse, hairy, dark brown to black, mycelium partly superficial, partly immersed, brown; colonies composed of conidiophores and sometimes ascomata. Anamorph. Setae present, mostly associated with ascomata (see below). Conidiophores 195-360 × 5-7.5 μm, 7-8.5 μm wide above the base, mononematous, macronematous, solitary, erect, straight or flexuous, unbranched, thick-walled, dark brown, paler towards the apex. Conidiogenous cells 20-54 × 5-6.5(-8) μm tapering to 3.5-4.5 μm below the collarette, integrated, terminal, monophialidic, extending percurrently, cylindrical to cylindrical-lageniform, brown, producing conidia successively; collarettes 6-7.5 μm wide, 2.5-3(-4) μm deep, funnel-shaped, pale brown. Conidia 10.5-12 μm long, 8.5-12 μm wide, 2.5-3.5 μm wide at the basal hilum (mean ± SD = 11.2 ± 0.5 × 10.3 ± 1.0 × 2.9 ± 0.3 μm), obpyramidal, in side view cuneiform to obtriangular, with four corners when viewed from above, truncate at the basal scar, with straight or curved setulae inserted at each corner 5-8 μm long, aseptate, hyaline, thin-walled, smooth; formed singly, adhered in basipetal chains. Teleomorph. Ascomata 120-140 μm diam, 130-160 μm high, subglobose, dark brown to black, superficial, solitary or aggregated, subglobose, papillate, setose. Setae 37-157 × 3.5-5.5 μm, simple, straight, cylindrical, brown, pale brown towards the apex, extending percurrently, apical cell sterile, 3.5-4 μm wide, broadly rounded, pale brown to subhyaline, similar setae arise around ascomata on the substrate. Ostiole periphysate. Ascomatal wall fragile, carbonaceous, 20-24 μm thick, two-layered. Outer layer consisting of brown, polyhedral cells with opaque walls. Inner layer consisting of several rows of thin-walled, hyaline cells. Paraphyses 4-5 μm wide, tapering to ca. 2 μm, septate, hyaline, longer than the asci. Asci 95-114 × (9-)10-12 μm (mean ± SD = 103.5 ± 6.5 × 10.9 ± 1.1 µm), cylindrical-clavate, short-stipitate, apically narrowly rounded, ascal apex with a non-amyloid apical annulus ca. 3 μm wide, 2 μm high. Ascospores 18-22(-23) × 4-5 μm (mean ± SD = 20.4 ± 1.3 × 4.4 ± 0.4 µm), fusiform, hyaline, 1-3-septate, smooth, 2-seriate in the ascus.

Culture characteristics.

On PCA: colonies 7-10 mm diam in 14d, circular, raised, margin entire, velvety-lanose, brown to dark grey-brown with whitish-grey conidial masses, reverse black. Sporulation abundant at the centre of the colony.

Colonies on PCA effuse, mycelium subhyaline to pale brown, 2-3 μm wide. Setae absent. Conidiophores, conidiogenous cells and conidia similar to those from nature. Conidiophores 74-141 × (4.5-)5-6 μm, 5.5-6.5 μm wide above the base, paler brown and less septate than those from nature, erect, straight. Conidiogenous cells 18-40 × 4.5-5.5 μm tapering to 3.5-4 μm below the collarette, cylindrical, pale brown; collarettes 5-6 μm wide, 3.5-4 μm deep, pale brown. Conidia 8-10(-11) μm long, 8-9(-10) μm wide, 2-2.5 μm wide at the hyaline basal hilum (mean ± SD = 9.7 ± 0.9 × 8.4 ± 0.6 × 2.0 ± 0.1 μm), cuneiform to obpyramidal, truncate at the basal scar, setulae not observed, aseptate, hyaline, thin-walled, smooth, formed basipetally in chains.

Other specimen examined.

New Zealand - West Coast region • Buller district, Victoria Forest Park, Reefton, Big River Inanganua track; on decaying wood of Nothofagus sp. (associated with C. novae-zelandiae PDD 119362 and Zanclospora falcata PDD 119365); 6 Mar. 2003, M. Réblová MR 2724/ NZ 225 (PDD 119364).

Habitat and geographical distribution.

Saprobe on decaying wood, known only in New Zealand.

Notes.

In the size of conidia, our species appears intermediate between Cha. bisetis and Cha. obconica ( McKenzie 1991). Chalarodes bisetis differs from Cha. obpyramidata in conidia longer and narrower at the apical end, (9.5-)12-14(-15) × 4.5-6(-9) μm, while Ch. obconica possesses conidia slightly shorter (8-)9-10.5(-11) μm and narrower at the basal hilum 1.75-2 μm.

Figures

Figure 8. Chalarodes obpyramidata A ascomata B colony composed of conidiophores C, H, O-Q conidiophores D-G, S, T conidia I-L, R upper parts of conidiophores with conidia M asci with ascospores N paraphyses. Images: PDD 119363 (A-L); PDD 119364 (M-T); on natural substrate (A-N); in PCA culture after 4 wk (O-T). Scale bars: 250 μm (A, B); 50 μm (C, H); 10 μm (D-G, M, N, R-T); 20 μm (I-L, O-Q).