Cora inversa Lücking & Moncada, 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 : 14-16

Cora inversa Lücking & Moncada , sp. nov. ( Fig. 7 )

Mycobank #805380

Genbank ITS barcoding sequence: KF443237

Differing from Cora hirsuta and the closely related C. byssoidea in the lobes with glabrous upper surface, tomentosestrigose lower surface, and submarginally produced soredia, and from C. minor in the larger lobes and submarginally formed soredia.

Holotype: — COLOMBIA. Cundinamarca: Choachí, Páramo El Verjón; 4º 33' N, 74º 00' E; 3200 m; 18 August 2008, Lücking 25902 (F).

Thallus epiphytic between bryophytes on thin branches and twigs of paramo shrubs or at the base on mossy soil, foliose, up to 5 cm across, composed of 1–5(–10) semicircular lobes per thallus; lobes 1–3 cm wide and 1–3 cm long, unbranched, white when fresh, with thickened, involute, irregular to fuzzy, white margins and a narrow, dark, submarginal zone forming granular soredia, white in the herbarium. Upper surface glabrous; involute margin with underside arachnoid-strigose; dark olive-brown submarginal zone forming soredia composed of cyanobacterial granules 30–50 µm in diam. embedded in a paraplectenchymatous hyphal sheath; lower surface ecorticate, finely arachnoid (representing the exposed medulla) to distinctly hirsute-strigose in parts caused by the formation of clusters of longer trichomes composed of agglutinated hyphae, white when fresh and becoming yellowish white in the herbarium. Thallus in section 200–300 µm thick, with upper cortex, photobiont layer, and medulla; upper cortex formed by a 50– 100 µm thick layer of loosely woven, irregularly arranged, 4–6 µm thick hyphae covered by a thin layer of distinctly periclinal, compacted hyphae and supported by a 30–50 µm high 'medullary' layer of irregularly arranged to anticlinal, 4–6 µm thick hyphae; photobiont layer 50–100 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 30–50 µm diam., individual photobiont cells 9–12 µm broad and 5–6 µm long, yellow-orange to olive-yellow in upper portions, penetrated by tubular fungal hyphae; heterocytes sparse, hyaline to pale yellow, 8–10 µm wide and 4–5 µm long; cells of hyphal sheath wavy in lateral outline, 3–4 µm thick; medulla 30–50 µm thick, composed of loosely woven, irregularly arranged to more or less periclinal hyphae 4–5 µm thick; clamp connections not observed.

Hymenophore not observed.

Chemistry: no substances detected by TLC.

Distribution and Ecology: —This species known from several collections growing on shrubs, particularly at their base, in the Colombian paramo.

Etymology: —The epithet refers to the partially strigose underside as opposed to a similar tomentum formed on the upper side by Cora hirsuta .

Remarks: — Cora inversa is one of several species producing soredia in the genus, most of which being undescribed. Sorediate margins are also known from Cora minor (Lücking, E. Navarro & Sipman) Lücking , comb. nov. [Mycobank #805389; bas.: Dictyonema minus Lücking, E. Navarro & Sipman in Chaves et al., Bryologist 107: 247 (2004); holotype: Costa Rica, Navarro 1688 (INB-3789873; isotypes, CR, F)], but in that species they are formed directly on the involute margin, whereas in C. inversa , they are formed in a thin submarginal zone on the upper side. In contrast to most other species of Cora , the lobes in C. inversa are not perfectly round but slightly irregular, together with the white surface and dark submarginal zone giving the species a very characteristic appearance. Cora hirsuta and the closely related C. byssoidea (see above) differ in the tomentose upper surface and the regularly rounded lobe margins lacking soredia; herbarium material can easily be confused if soredia are indistinct and the upper and lower surface are not properly recognized.

Additional specimens examined: — COLOMBIA. Cundinamarca: Choachí, Páramo El Verjón; 4º 33' N, 74º 00' E; 3200 m; 18 August 2008, Lücking 25903 (F) .

Figures

FIGURE 7. Cora inversa. A. Specimen in the field showing irregular-fuzzy lobe margins and clusters of trichomes projecting from lower surface (Colombia, Lücking 33340). B. Lobes enlarged showing marginal soredia (Colombia, Lücking 33308). C. Lobe underside showing arachnoid surface (Colombia, Lücking 25902). Scale in A–B = 10 mm, in C = 1 mm.