Cora cyphellifera Dal-Forno, Bungartz & Lücking, 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 : 12-14

Cora cyphellifera Dal-Forno, Bungartz & Lücking , sp. nov. ( Fig. 6 )

Mycobank #805379

Genbank ITS barcoding sequence: KF443242

Differing from Cora pavonia in the light aeruginous color and pitted surface, the stereoid-cyphelloid hymenophore, and the epiphytic growth habit, and from the closely related C. arachnoidea in the pitted, undulate, otherwise glabrous surface, the stereoid-cyphelloid hymenophore, and the epiphytic growth habit.

Holotype: — ECUADOR. Imbabura: Andes, Cantón Cotacachi ; 22º 29.8' N, 78º 27' 24.6'' W; 2053 m; small

entrance driveway towards the Reserva Alto Chocó near Intag , just before the small bridge over the river; 26 June 2012, Dal-Forno 1808 ( GMUF) .

Thallus epiphytic on twigs and branches of trees, foliose, up to 15 cm across, composed of 20–30 semicircular lobes per thallus; lobes 3–5 cm wide and 2–3 cm long, lacking branching sutures, light aeruginous with slight concentric color zonation when fresh, with shallow concentric ridges (8–11 per cm lobe length) and shallowly but distinctly pitted, with thin but distinct, involute, white to light grey margins, becoming light yellowish grey to dark grey in the herbarium. Upper surface glabrous; involute margin finely arachnoid; lower surface ecorticate, glabrous, light aeruginous when fresh and becoming light yellowish grey in the herbarium. Thallus in section 285–400 µm thick, with upper cortex, photobiont layer, and medulla; upper cortex formed by a 25–35 µm thick layer of rather densely packed, periclinal, 4–5 µm thick hyphae supported by an indistinct, 80–120 µm high 'medullary' layer of spaced groups of densely packed, anticlinal, 3–5 µm thick hyphae; photobiont layer 60–80 µm thick, composed of clusters of short, coiled cyanobacterial filaments wrapped in a dense, paraplectenchymatous hyphal sheath formed by jigsaw puzzle-shaped cells, clusters 40–70 µm diam., individual photobiont cells 8–11 µm broad and 6–8 µm long, bluish green to orange-yellow 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 100–200 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 stereoid to cyphelloid structures irregularly dispersed along the margins on the underside, 5–10 mm long and 10–15 mm broad, with white, smooth surface and smooth margins; hymenophore in section 70–100 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 × 5–8 µm; basidia 18–25 × 7–9 µm, 4- sterigmate; basidiospores ellipsoid to lacrymoid, non-septate, hyaline, 7–8 × 2.5–3.5 µm.

Chemistry: no substances detected by TLC.

Distribution and Ecology: —This species is known from the type collection in a montane rain forest in northern Ecuador, where it was found growing on small trees in open, disturbed forest patches.

Etymology: —The epithet refers to the unusual type of hymenophore.

Remarks: —This remarkable new species is characterized by its distinctly aeruginous color, the pitted surface, and particularly the hymenophore becoming cyphelloid, differing markedly from all other species of the genus, including the closely related C. arachnoidea (see above). Cora pavonia (see above) also has an undulate lobe surface, but is brownish in the field, lacks pits, has a corticioid hymenophore, and always grows terrestrial between bryophytes. In contrast to other species of Cora where the hymenophore is corticioid and evenly distributed on the lobe underside, in C. cyphellifera it almost looks like the lichenized thallus is parasitized by a non-lichenized, cyphelloid mushroom. The hymenophore is very similar to the basidiomata found in the related genus Cyphellostereum ( Lawrey et al. 2009) . In his lengthy account on what he considered ecomorphological variation of a single species, Möller (1893) reported Cora lichens with bluish thalli that produced cyphelloid basidiomata, concluding that supposedly 'free-living' basidiomata and those that are lichenized and form Cora thalli represent the same fungal species. It is very likely that he had observed the same species as described here and did not consider the possibility that different fungal species can form very similar fruiting bodies.

Figures

FIGURE 6. Cora cyphellifera. A. Specimen in the field (holotype). B. Lobe underside showing cyphelloid hymenophores (holotype). C. Aspect of habitat at type locality in Ecuador. Scale in A–B = 10 mm.