Cora barbulata – Facesoffungi number: FoF 01049

Cora barbulata Lücking, Dal-Forno & Lawrey

Index Fungorum number: IF551501 Facesoffungi number: FoF01049

Etymology: Referring to the beard-like concentric rings of irregular tomentum on the upper lobe surface.

Holotype: R. Lücking R18 (CR). Diagnosis: Differing from the morphologically similar Cora aspera in the crenulate, undulate lobe margins and the large, broad hymenophore patches. Thallus epiphytic on stems and branches of shrubs, foliose, up to 15 cm across, composed of 1–5(−10) semicircular lobes per thallus; lobes 2–7 cm wide and 1–5 cm long, often branched and with short radial branching sutures, marginally distinctly crenulate (with short secondary branches) and undulate, light bluish to greenish or brownish grey with slight concentric colour zonation when fresh, with thin but distinct, involute, white to light grey margins, becoming white to grey in the herbarium. Upper surface smooth, glabrous except for a few concentric lines of short, irregular, white trichomes; trichomes 0.2–0.3 mm long and 7–15 μm thick at the base, composed of agglutinated hyphae; involute margin glabrous; lower surface ecorticate, finely felty-arachnoid (representing the exposed medulla), 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 20–50 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 50–120 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 11–13 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, 9–11 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 angularrounded, resupinate patches irregularly dispersed on the underside, patches 5–15 mm diam., with pale orange-yellow, smooth surface and felty, involute margins; hymenophore in section 50 – 100 μ m 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 25–35×5–6 μm; basidia 25–40×6–7 μm, 4-sterigmate; basidiospores not observed. Chemistry: No substances detected by TLC.

Material examined: COSTA RICA, San José, Los Santos Forest Reserve, km 90 on road (ruta 2) from Cartago to San Isidro, access road to towers on summit; 83° 45′ W, 09° 34′ N, 3400–3450 m; upper montane cloud forest and subalpine paramo zone, disturbed low paramo shrub with Chusquea, on stems and twigs of unidentified shrubs; 12 September 2007, R. Lücking 21007 (CR holotype; F isotype); same locality; 21 May 2012, M. Dal-Forno 1710, 1712 (GMUF paratypes); COSTA RICA, Cartago: Tapantí-Cerro de la Muerte National Park, km 90 on road (ruta 2) from Cartago to San Isidro, roadside forest remnants; 83° 45′ W, 09° 34′ N, 3350–3400 m; upper montane cloud forest zone, disturbed low oak forest, on stems and twigs of unidentified shrubs; 21 May 2012, M. Dal-Forno 1713, 1714 (GMUF paratypes).

Distribution and ecology: Known from several collections as shrub epiphyte in the upper montane cloud forest and paramo zone in the Cordillera de Talamanca in Costa Rica. Notes: Cora barbulata is morphologically similar to C. aspera Wilk et al. (Lücking et al. 2013) in the epiphytic growth habit, the rather large thallus composed of several lobes, and the concentric lines of irregular tomentum. The two species are, however, only distantly related, each falling into one of the two major Cora clades (Lücking et al. 2014). A closer relative of C. barbulata is the terrestrial C. arachnoidea J. E. Hern. & Lücking, which is grey-brown when fresh and uniformly thinly tomentose on the upper surface (Lücking et al. 2013). Cora barbulata can be distinguished from C. aspera mainly by the coarsely crenulate, undulate lobe margins and the different hymenophore, forming large, irregularly dispersed patches on the underside.