Plectania damingshanensis G. F. Mou & J. R. Liu sp. nov.

Figs 2, 3, 4

Etymology.

The specific epithet refers to the type locality, Damingshan National Nature Reserve, in China.

Diagnosis.

It is characterized by the cupulate ascomata, the surface of hymenium with brownish orange to light brown color, external surface and stipe (when present) densely covered with grey tomentum and tree-like ridges, the elliptical ascospore is warty under SEM, (21.7) 22.5–32.0 (34.6) × (11.0) 12.1–14.7 (16.5) μm.

Holotype.

China • Guangxi Zhuang Autonomous Region, Nanning City, Damingshan National Nature Reserve, 23°49'N, 108°43'E, ca 1230 m alt., on rotten fallen sticks or wood surrounded by moss in the evergreen broad-leaved forest, 19 Feb. 2024, Guang R. Zhou (DMS 2024022001, IBK, holotype!) (ITS: PP 864720; nrLSU: PP 859016; rpb 1: PV 247118).

Description.

Apothecium cupulate, up to 19–27 mm in diameter, 20–30 mm high, subsessile to stipitate (Fig. 2 a, b). Hymenium surface glabrous, without ornamentation or wrinkled, brownish orange (6 C 6) to light brown (6 D 7), brown-dark, brown (6 E 8–6 F 8) after drying, margin with light brown (6 D 5) tomentum. External surface reddish brown-dark brown (7 D 8–7 F 8), brownish grey (8 F 2) after drying. Stipe (when present) up to 2–20 mm long, 7.5–9 mm in width, densely covered with grey (8 D 1–8 F 1) tomentum and tree-like ridges extending all the way to the margin of the cup (Fig. 2 b, d). Flesh solid, wet, gelatinous at a high level, semitransparent, slight grey (8 B 1). Odor and taste not special.

External hairs curved and flexuous, septate, glabrous, brown (6 E 7) with an olive tint (1 E 8), 5–8.5 μm in diameter, with obtuse end (Fig. 3 g, h). Ectal excipulum of textura angularis made up of thick-walled cells, brownish to dark brown, 13–91 μm thick (Fig. 3 g), near the margin arranged in separable moniliform hair-like cells, 6.2–10.6 μm diam (Figs 3 f, 4 g). Medullary excipulum of loose textura intricata immersed in a highly gelatinous matrix, approximately 380–1000 μm, subhyaline to yellowish white (2 A 2), composed of 2–4.2 μm broad hyphae (Figs 3 c, 4 f). Subhymenium of a dense textura intricata of closely septate hyphae, olive brown (4 D 7–4 D 6), 50–80 μm thick. Asci cylindrical, suboperculate, 8 - spored, rarely with 7 spores, thick-walled, inamyloid, 322–401 (426) × 11.0–15.6 (Fig. 3 j – m, 4 a). Paraphyses 1.5–3 μm diam, filiform, septate, branched, slightly enlarged or narrowed near apex (Figs 3 d, 4 d). Ascospores uniseriate, ellipsoid, equilateral, hyaline, very finely warty under light microscope (× 1000, Fig. 3 i), verrucose to vermicular under scanning electron microscope (Fig. 16 b), with 1–2 guttules, [40 / 5 / 2] (21.7) 22.5–32.0 (34.6) × (11.0) 12.1–14.7 (16.5) μm, Q = (1.7) 1.8–2.3 (2.6), Q av = 2.0. Hymenial hairs cylindrical, comparable in length to the paraphyses, non-septate, 2.1–4.4 μm in diameter, concolor with paraphyses due to the homogeneous pigments, agglutinating or intermingle with paraphyses to bundles, tips rounded to slightly subcapitate, straight or curved, unbranched (Figs 3 e, 4 c). Anamorph unknown.

Habitat.

Growing in scattered to gregarious groups on moss-covered decaying wood in broadleaf forests.

Geographic distribution.

So far, only known from Guangxi Zhuang Autonomous Region, China.

Other specimens examined.

China • Damingshan National Nature Reserve, 23°49'N, 108°43'E, alt. 1225 m, on wood surrounded by moss in the evergreen broad-leaved forest, 19 Feb. 2024, Guang R. Zhou, DMS 2024022002 (IBK!) (ITS: PP 864721; nrLSU: PP 859017; tef 1 - α: PV 295998); DMS 2024022003 (IBK!) (ITS: PP 864722; nrLSU: PP 859018). Mao’ershan National Nature Reserve, 25°88'N, 110°37'E, ca 720 m alt., on rotten fallen sticks, 6 April 2024, Yan C. Zhang, MES 024040606 (IBK!) (ITS: PQ 691392; nrLSU: PQ 682446; rpb 1: PV 247119; tef 1 - α: PV 295999).

Notes.

In the phylogenetic tree (Fig. 1), P. damingshanensis and P. lutea were grouped together with strong support (MLB = 100 %, BPP = 1). Both species share ellipsoid and verrucose ascospores with similar dimensions: P. damingshanensis measures (21.7) 22.5–32.0 (34.6) × (11.0) 12.1–14.7 (16.5) μm, while P. lutea measures (24.5) 27.0–30.0 (32.0) × (12.2) 13.0–15.0 (16.0) μm (Mou and Bau 2021). However, the external surface of P. damingshanensis is densely covered with grey tomentum and tree-like ridges that extend to the margin, and its apothecium is larger with a longer and thicker stipe. While the external surface of P. lutea has fewer brown hairs and irregular, vascular ridge-like protrusions, with ascomata measuring only 11.0–18.0 mm in diameter. P. sichuanensis is distinguished from P. damingshanensis by its hymenium, which is ochre in color and lacks a noticeable covering of black hairs, and its smaller, smooth ascospores (22–26 × 11–13 μm) (Zeng et al. 2021).

From a microscopic perspective, the ascospores of P. damingshanensis, as well as those of P. zugazae Calonge & Alb. García, P. melastoma described in older mycological literature, and P. harnischii M. Carbone, Agnello, A. D. Parker & P. Alvarado, are all elliptical and verrucose (Carbone et al. 2015 a, 2021). However, there are significant differences in ascospore size among the four species, P. damingshanensis having larger ascospores [(21.7) 22.5–32.0 (34.6) × (11.0) 12.1–14.7 (16.5) μm], while ascospores of P. zugazae [18–22 × 12–14 μm] and P. melastoma [21.8–25 × 10–12.4 μm] are notably smaller. As for P. harnischii, it exhibits the narrower ascospores with a size of 20.2–24.8 × 8.1–11.2 µm.

Plectania damingshanensis exhibits numerous similarities to species within the Galiella genus, featuring brightly colored ascocarps, highly gelatinized fleshy tissue, and ascospore surfaces adorned with wart-like ornamentation. However, on the phylogenetic tree, P. damingshanensis does not cluster with G. amurensis and G. rufa. Additionally, it is noteworthy that the ascospores of G. amurensis lack oil droplets, and its asci (measuring 400–450 × 12–17 μm) and ascospores [measuring (26) 28–37.5 (40) × 11.5–17.5 (18) μm] are larger compared to those of P. damingshanensis. Conversely, the asci (measuring 270 × 12 μm) and ascospores [measuring (17) 18–21 (23) × 8–10 μm] of G. rufa are smaller (Carbone et al. 2015 b).