Cora strigosa Lücking, E. Paz & L. Salcedo, 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 : 18-20

Cora strigosa Lücking, E. Paz & L. Salcedo , sp. nov. ( Fig. 9 )

Mycobank #805383

Genbank ITS barcoding sequence: KF443241

Differing from the morphologically similar Cora hirsuta and the closely related C. byssoidea in the strigose tomentum developed mostly submarginally.

Holotype: — PERU. Cuzco: Piscacucho ; 13° 10' S, 72° 21' W, 2700–3800 m; disturbed montane rainforest and pasture; 4 August 2009, Paz & Salcedo 3 (F).

Thallus on rocks associated with other lichens ( Hypotrachyna and Rimelia ), foliose, up to 10 cm across, composed of 1–3 semicircular lobes per thallus; lobes 1–3 cm wide and 1–2 cm long, unbranched, greenish grey when fresh, with thin, involute, grey margins, white-grey in the herbarium. Upper surface densely hirsute-strigose or sometimes glabrous towards the base, with the trichomes arranged in broad, concentric zones; trichomes free, more or less projecting radially towards the margin (as if combed), 1–1.5 mm long and 25–50 µm thick at the base, composed of agglutinated hyphae; involute margin with underside very minutely arachnoid; lower surface ecorticate, finely felty-arachnoid (representing the exposed medulla), white-grey. Thallus in section 250–350 µm thick, with upper cortex, photobiont layer, and medulla; upper cortex formed by a 25–50 µm thick layer of rather loosely packed to indistinctly periclinal, 4–5 µm thick hyphae supported by a 25–50 µm high 'medullary' layer of spaced groups of densely packed, anticlinal, 3–5 µm thick hyphae; photobiont layer 50–150 µm thick, irregular, 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 5–7 µm long, dark blue-green to orange-yellow in upper portions, penetrated by tubular fungal hyphae; heterocytes sparse, hyaline to pale yellow, 8–10 µm wide and 5–6 µm long; cells of hyphal sheath wavy in lateral outline, 3–4 µm thick; medulla 50–80 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 irregular to elongate, resupinate patches arranged in reticulate pattern or more or less concentric zones on the underside, patches 1–3 mm long and 0.5– 1 mm broad, with white to pale yellowish, finely arachnoid surface and slightly involute, finely byssoid 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, as well as numerous projecting hairs formed by single, cylindrical hyphae 20–50 µm long and 4–5 µm thick; basidioles 25–35 × 5–6 µm; basidia 30–40 × 5–7 µm, 4-sterigmate; basidiospores not observed.

Chemistry: no substances detected by TLC.

Distribution and Ecology: —This species is known from a single locality in a heavily disturbed montane rain forest in Peru, near Machu Picchu.

Etymology: —The epithet refers to the radially projecting, conspicuous trichomes.

Remarks: —This species at first glance resembles Cora hirsuta ( Lumbsch et al. 2011) in forming rather large, free trichomes, but is not closely related to the latter, as it falls into another clade ( Dal-Forno et al. 2013). Morphologically it can be distinguished by the trichomes developing up to and especially near the margin, whereas C. hirsuta features a thin, glabrous, submarginal zone of different color ( Lumbsch et al. 2011). Also, the finely arachnoid surface of the hymenophore, caused by numerous hyphae projecting from the hymenium surface, is unique within the genus. More closely related is C. byssoidea (see above), which differs in the more irregular, interwoven tomentum and the glabrous hymenophore surface.

Additional specimens examined: — PERU. Cuzco: Piscacucho ; 13° 10' S, 72° 21' W, 2700–3800 m; disturbed montane rainforest and pasture; 4 August 2009, Díaz & Jihuallanco s.n. (F) .

Figures

FIGURE 9. Cora strigosa. A. Aspect of typical habitat in the Peruvian Andes near Machu Picchu. B. Lobe enlarged showing strigose upper surface (holotype). C. Lobe underside showing hymenophore with finely arachnoid surface (holotype). Scale in B = 5 mm, in C = 1 mm.