Cora aspera Wilk, Lücking & E. Morales, 2013

Lücking, Robert, Dal-Forno, Manuela, Lawrey, James D., Bungartz, Frank, Holgado Rojas, María E., Hernández, Jesús E., Marcelli, Marcelo P., Moncada, Bibiana, Morales, Eduardo A., Nelsen, Matthew P., Paz, Elias, Salcedo, Luis, Spielmann, Adriano A., Wilk, Karina, Will-Wolf, Susan & Yánez-Ayabaca, Alba, 2013, Ten new species of lichenized Basidiomycota in the genera Dictyonema and Cora (Agaricales: Hygrophoraceae), with a key to all accepted genera and species in the Dictyonema clade, Phytotaxa 139 (1), pp. 1-38 : 8-10

Cora aspera Wilk, Lücking & E. Morales , sp. nov. ( Fig. 4 )

Mycobank #805377

Genbank ITS barcoding sequence: KF443231

Differing from the superficially similar Cora arachnoidea in the absence of a dense, distinct upper tomentum and in the epiphytic growth habit, and from the closely related C. pavonia in the plane lobe surface with scattered, indistinct upper tomentum, and in the epiphytic growth habit.

Holotype: — BOLIVIA. Santa Cruz: Caballero, Siberia region near La Palma; 17° 49' S, 64° 40' W, 2582 m; Yungas cloud forest, epiphytic on bark; 12 December 2004, Wilk 2780b ( KRAM; isotype: LPB).

Thallus epiphytic on twigs and branches of trees, foliose, up to 7 cm across, composed of 1–5 semicircular lobes per thallus; lobes 1–5 cm wide and 1–5 cm long, often branched and with short radial branching sutures, light greenish grey with slight concentric color zonation when fresh, with thin but distinct, involute, white to light grey margins, becoming white to (dark) grey in the herbarium. Upper surface rough and thinly scabrose in thin, concentric lines but lacking a continuous, distinct tomentum; trichomes where present in concentric lines, free and irregularly arranged, 0.1–0.15 mm long and 5–10 µm thick at the base, composed of agglutinated hyphae; involute margin usually shortly pilose; lower surface ecorticate, finely felty-arachnoid (representing the exposed medulla) to almost glabrous, light grey when fresh and becoming white in the herbarium. Thallus in section 200–300 µm thick, with upper cortex, photobiont layer, and medulla; upper cortex formed by a 25–50 µm thick layer of rather loosely packed, irregularly arranged to nearly periclinal, 4– 5 µm thick hyphae supported by an indistinct, 20–30 µm high 'medullary' layer of spaced groups of densely packed, anticlinal, 3–5 µm thick hyphae; photobiont layer 70–120 µm thick, composed of clusters of short, coiled cyanobacterial filaments wrapped in a dense, paraplectenchymatous hyphal sheath formed by jigsaw puzzle-shaped cells, clusters 20–30 µm diam., individual photobiont cells 10–13 µm broad and 5–8 µm long, dark blue-green to lighter green in upper portions, penetrated by tubular fungal hyphae; heterocytes sparse, hyaline to pale yellow, 9–12 µm wide and 5–6 µm long; cells of hyphal sheath wavy in lateral outline, 3–4 µm thick; medulla 50–100 µm thick, composed of loosely woven, irregularly arranged to more or less periclinal hyphae 4–5 µm thick; clamp connections not observed.

Hymenophore developed as elongate, resupinate patches forming more or less concentric ridges on the underside, patches 1–10 mm long and 0.5– 1 mm broad, with pale yellow, smooth surface and smooth, involute margins; hymenophore in section 50–100 µm thick, composed of a paraplectenchymatous layer resting on loose, 4–6 µm thick, generative medullary hyphae and supporting the hymenium; hymenium composed of numerous, palisade-like basidioles and scattered basidia; basidioles 20–35 × 5–6 µm; basidia 25–40 × 6–7 µm, 4-sterigmate; basidiospores not observed.

Chemistry: no substances detected by TLC.

Distribution and Ecology: —This species is known from several collections from Costa Rica, Colombia, Ecuador, Bolivia, and Peru. It appears to be a primarily epiphytic species, growing on twigs and branches of trees and shrubs in (upper) montane rain forest and paramo vegetation, where it competes with other foliose macrolichens such as Leptogium spp. , Lobariella spp. , and Sticta spp.

Etymology: —The epithet refers to the rough appearance of the surface especially when dry.

Remarks: — Parmasto (1978) and other authors ( Mitidieri et al. 1964; Feige 1969; Oberwinkler 1970, 1984, 2001; Parmasto 1978; Coxson 1987a –c; Fritz-Sheridan & Portecop 1987; Iacomini et al. 1987; Fritz- Sheridan 1988; Hawksworth 1988; Larcher & Vareschi 1988; Wolf 1993; Lange et al. 1994; Piovano et al. 1995; Thomas et al. 1997; Azenha et al. 1998; Trembley et al. 2002a, b; Carbonero et al. 2002; Elifio et al. 2002) considered Dictyonema glabratum (including Cora pavonia ) to be a species with wide distribution and broad ecological amplitude, being found on a wide range of substrata. The data now available indicate that this is not the case. The many species recognized phylogenetically and morphologically also have distinct substrate preferences, growing either on bare soil, among bryophytes, on rock, or epiphytic on branches, rarely on tree trunks. Cora aspera is one of a few species growing typically as an epiphyte and it is thus far the largest and most common epiphytic species known in the genus. It resembles the distantly related C. arachnoidea in dry condition but can be distinguished by the lack of a dense tomentum covering the entire upper surface and by the much finer, almost reticulate hymenophore. The latter is similar to that found in the more closely related C. pavonia , but that species differs by its terrestrial growth in bryophyte mats and its distinctly brownish color when fresh, as well as its coarsely undulate surface.

Additional specimens examined: — COSTA RICA. Puntarenas: Coto Brus, San Vito, Las Cruces Biological Station and Botanical Garden ; September 2007, Lücking 21016 (F) . BOLIVIA. La Paz: Murillo, Valle de Zongo, Laguna de Viscachani , a las orillas de la laguna; 16º 12' S, 68º 08' W, 3805 m; piso altoandino con pajonales y vegetación baja, 13 November 2007, Lücking 23564 (F, LPB) . Cochabamba: Chapare, Incachaca ; 17° 13' S, 65° 50' W, 2018 m; 7 July 2009, Lücking 29128 (F, HCUCB) . Cochabamba: Chapare, Corani ; 17° 16' S, 65° 54' W, 3262 m; 7 July 2009, Lücking 29356, 29364 (F, HCUCB) . PERU. Cuzco: Aguas Calientes, near Machu Picchu ; August 2009, Vera s.n. (F) .

Figures

FIGURE 4. Cora aspera. A. Specimen in the field (Colombia, Lücking 33332). B. Lobe enlarged showing rough upper surface (holotype). C. Lobe underside showing hymenophore with slightly involute, smooth margins (holotype). Scale in A–B = 10 mm, in C = 1 mm.