Gyalidea lluxitensis Flakus, Suchan, Plata & Rodr. Flakus, in Cao et al., Fungal Diversity 132: 457 (2025)
Index Fungorum number: IF 855029; MycoBank number: MB 855029; Facesoffungi number: FoF 17095; Figs. 1, 2
Etymology – the epithet refers to Mt. Wila Lluxita, the locality of the type specimen.
Holotype – KRAM-L 75069.
Thallus crustose, epilithic, 0.5–7 cm wide, continuous to sparsely fissured, not areolate, pale greenish gray with a pinkish tinge, pale to dark grayish brown or almost black, dull, 30–80 µm thick, smooth, composed of hyaline, vertically oriented hyphae. Cortical layer 5–9 µm thick, paraplectenchymatous, consisting of dark pigmented hyphae. Photobiont chlorococcoid, cells broadly ellipsoid to subglobose, 5–10 µm diam.
Apothecia orange-brown to dark-brown, sometimes pale brown-orange with rose tinge, scattered, usually solitary or in small groups of 2–3, immersed in the thallus (when young) to sessile and constricted at the base (when mature), 0.3–0.8 mm diam., 200–500 µm tall, rounded; in a section usually with a pinkish pigment (dissolving in K). Margin thick to evanescent, pale to dark brown. Disc concave to flat, pale brown-orange with rose tinge, pale to dark brown, usually paler than margin, smooth, epruinose, sometimes translucent when wet. Exciple laterally 70–150 µm thick, 100–300 µm thick at the base, composed of radiating hyphae, inner portion proso- to paraplectenchymatous of hyaline, thick-walled hyphae (hyphal lumina 1–3 × 2–6 µm), outer portion of thin-walled, grayish brown pigmented hyphae (hyphal lumina 0.5–2 × 2–7 µm), mixed with photo biont cells. Epihymenium 5–15 µm thick, pale yellowish to grayish brown, K–. Hymenium 110–150 µm thick, hyaline, not inspersed, non-amyloid, K–. Subhymenium hyaline or very pale yellowish/pinkish, 30–40 µm thick, K–, K/I–; hyphae variously orientated. Hypothecium hyaline to very pale yellowish/pinkish, 100–150 µm thick, K–, composed of short-celled, thick-walled hyphae. Paraphyses simple to sparsely branches and anastomoses, 1–1.5 µm thick, apices slightly swollen, 2–3 µm wide. Asci narrowly clavate to cylindrical or broadly clavate, multi-spored (= 60 spored), 75–160 × 9–22 µm, wall and contents non-amyloid; asco plasm K/I + orange; apex rounded at maturity, with an evident tholus (7–18 µm tall), with or without apical apparatus. Ascospores colorless, 0(–1)-septate, broadly to narrowly ellipsoid, sometimes slightly bent or tapering to one end, with a gelatine perispore when immature, (6–)7–11(–12.5) × (2–)3.5–5.5(–7) µm (n = 60); 1-septate slightly constricted at the septa. Pycnidia immersed, opening irregularly, hole- or crack-like, usually marginal. Conidiogenous cells hyaline, narrowing upwards, 4–10 × 1–2 µm. Conidia hyaline, simple, narrowly ellipsoid, 2.5–4.5 × 11.5 µm (n = 40).
Material examined – BOLIVIA, Dept. La Paz, Prov. Los Andes, near road Lipichi-Peñas, above Laguna Jankho Kkota, 16º03’20″S, 68º18’12″W, 4898 m, Mt. Wila Lluxita, subnival vegetation of Humid Puna, small stream below glacier, on submerged granite rock, 5 Dec 2016, A. Flakus 28,919 & P. Rodriguez-Flakus (KRAM-L 75069, holotype; LPB, isotype), 28,929 (KRAM-L 75070, LPB), 28,925 (KRAM-L 75071, LPB), 28,916 (KRAM-L 75072, LPB); below Mt. Wila Lluxita, 16º03’19.51″S, 68º18’07.13″W, 4877 m, subnival vegetation of Humid Puna, small stream below glacier, on submerged granite rock, 5 Dec 2023, A. Flakus 30,029, T. Suchan & O. Plata (KRAM-L 75073, LPB), 30,035 (KRAM-L 75074, LPB).
GenBank – KRAM-L 75069: PQ654506 (ITS), PQ619019 (nucLSU), PQ619023 (mitSSU); KRAM-L 75070: PQ654508 (ITS), PQ619021 (nucLSU), PQ619025 (mitSSU); KRAM-L 75071: PQ654507 (ITS), PQ619020 (nucLSU), PQ619024 (mitSSU); KRAM-L 75072: PQ654505 (ITS), PQ619018 (nucLSU), PQ619022 (mitSSU).
Notes – Gyalidea lluxitensis is an epilithic, fresh-water lichen, characterized by large, sitting to constricted apothecia, thin, sparsely fissured thallus, multispored (= 60-spored) asci and predominantly simple ascospores, (6–)7–11(–12.5) × (2–)3.5–5.5(–7) µm. Although the morphology of the new species does not fully fit the concept of Gyalidea (especially the simple ascospores), our ML and BI phylogenetic analyses (Fig. 2) strongly supported its generic placement within this genus. Gyalidea contains only six species developing multispored asci: Gyalidea asteriscus (Anzi) Aptroot & Lücking, G. luzonensis (Kalb & Vezda) Aptroot & Lücking, G. multispora Lumbsch & Vezda, G. polyspora R. Sant., G. vezdae S. Y. Kondr., Lokös, J. P. Halda & Hur and G. vonkonratii Lumbsch & Papong (Vezda and Poelt 1991; Aptroot and Lücking 2003; Nordin et al. 2007; Lumbsch et al. 2009; Kondratyuk et al. 2019). All of them, however, can be distinguished by having constantly 1- to multiseptate or sub- to muriform ascospores, and different sizes, colors and morphology of apothecia.
Figure 1 – Gyalidea lluxitensis (KRAM-L 75069, holotype). a, b Habit of ascomata growing on granite. c Transversal section of ascoma in LPCB. d Transverse section of exciple in LPCB. e Transversal section of thallus composed of vertically oriented hyphae mixed with photobiont cells and dark-pigmented cortical layer in LPCB. f External view of thallus showing cells of cortical layer (large opening caused by protruding photobiont cells). g Asci mounted in Lugol’s solution pretreated by 10% KOH. h Ascus apical apparatus mounted in Lugol’s solution pretreated by 10% KOH. i Ascospores in distilled water. Scale bars: a, b = 500 µm, c = 100 µm, d = 25 µm, e–i = 10 µm.
Figure 2 – Phylogenetic reconstruction of the systematic position of Gyalidea lluxitensis inferred from ML analyses of combined dataset of nucLSU, ITS and mitSSU. Bold branches represent either bootstrap values = than 70 and/or Bayesian posterior probabilities = than 0.95. New species is shown in red. “T” refers to a type specimen.