Sticta carrascoensis Ossowska, Kukwa, B. Moncada & Luecking, 2022

Ossowska, Emilia Anna, Moncada, Bibiana, Kukwa, Martin, Flakus, Adam, Rodriguez-Flakus, Pamela, Olszewska, Sandra & Luecking, Robert, 2022, New species of Sticta (lichenised Ascomycota, lobarioid Peltigeraceae) from Bolivia suggest a high level of endemism in the Central Andes, MycoKeys 92, pp. 131-160 : 131

Sticta carrascoensis Ossowska, Kukwa, B. Moncada & Luecking sp. nov.

Fig. 5

Diagnosis.

Differing from S. andina in the green algal photobiont, the absence of vegetative propagules and the yellow medulla.

Type.

Bolivia. Dept. Cochabamba; Prov. Carrasco, Parque Nacional Carrasco, Meruvia close to Monte Punku , 17°35'06"S, 65°14'54"W, elev. 3283 m, Podocarpus-Polylepis forest, Ceja de Monte Inferior (Altimontano), corticolous, 26 Nov 2014, M. Kukwa 15028 (holotype UGDA, isotype LPB) .

Description.

Primary photobiont a green alga. Stipe absent. Thallus irregular to suborbicular, up to 30 cm diam., moderately branched, with 3-5 branches per 5 cm radius, branching pleurotomus; lobes laciniate to flabellate, interspaced to adjacent, involute, with their apices rounded and plane to involute and their margins entire, not thickened; lobe internodes (3-)6-9(-10) mm long, (3-)9-10(-12) mm broad; thallus coriaceous. Upper surface shallowly scrobiculate to rugose, yellow-brown to light brown, with darker apices in the herbarium, shiny; surface glabrous, without papillae, pruina and weakly maculate; marginal cilia present, brown, about 0.2 mm long, fasciculate. Apothecia abundant, marginal to laminal, dispersed to arranged, sometimes imbricate, subpedicellate, with pronounced invagination on lower side, up to 4 mm diam.; disc orange-brown (young apothecia) to red-brown (older apothecia), very shiny when young; margin crenate, hirsute, with dark brown hairs. Vegetative propagules absent. Lower surface somewhat ridged, yellow to dark brown towards the centre; primary tomentum dense to the margin, thick, thinner towards the margin, spongy, soft, pale to dark brown; secondary tomentum very scarce, up to 25 μm. Rhizines present, about 2 mm, brown with paler tips, fibrillose. Cyphellae 1-10 per cm2 towards the thallus centre and 21-40 per cm2 towards the margin, scattered, round to irregular, urceolate with wide pore, erumpent to prominent, remaining below the level of the primary tomentum, with the margin raised and involute, brown-coloured, without tomentum or with in the lower part; pore (0.2-)0.3-0.5(-0.6) mm diam.; basal membrane pruinose in the appearance, white to yellow, K- to K+ yellow, C-, KC-, Pd-. Medulla compact, pale yellow to yellow, K+ lemon-yellow, C-, KC-, Pd-. No substances detected by TLC.

Upper cortex paraplectenchymatous, external part orange-brown, 40-60 μm thick, consisting of 6-7 cell layers with cells 5-10 μm diam. (with smaller cells in outside parts of the cortex), their walls 2-3 μm thick and their lumina rounded to isodiametric, 3-10 μm diam., up to 12 μm broad. Photobiont layer 25-35 μm thick, its cells 4-6 μm diam. Medulla 120-150 μm thick, its hyphae 1.5-4.5 μm broad, without or with yellow crystals. Lower cortex paraplectenchymatous, 25-30 μm thick, with 3 cell layers; cells 6-16 μm diam., their walls 1-3 μm thick. Hairs of lower primary tomentum up to 1 mm long, in fascicles up to 12, forming intricate mass in the dense part of tomentum, hyphae unbranched, 5-7 μm broad, septate with free apices. Cyphella cavity up to 250 μm deep; loosely packed cells of basal membrane sometimes with one papilla. Apothecia biatorine, up to 1 mm high, without or very short stipe, about 300 μm long; excipulum up to 100 μm broad, laterally with projecting hairs, simple or in groups, hyphae rarely branched, up to 180 μm long. Hymenium up to 100 μm high; epihymenium up to 25 μm high, pale brown, without gelatinous upper layer. Asci 6-8-spored, ascospores fusiform, 1-3-septate, 26-33 × 7-9 μm.

Habitat and distribution.

Sticta carrascoensis was collected at a single locality in the Parque Nacional Carrasco in the Department Cochabamba, at an altitude of 3283 m. The specimen grew on the bark of a tree in Podocarpus-Polylepis forest.

Etymology.

The name refers the type locality.

Notes.

Sticta carrascoensis is phylogenetically close to S. andina , although this relationship is not supported (Fig. 1 ; Suppl. material 3: Fig. S1). The latter differs by its cyanobacterial photobiont and the formation of isidia and/or phyllidia, not observed in S. carrascoensis . The thalli in S. andina are smaller (up to 15 cm in diam.), the margins of the lobes are sparsely covered by cilia and the medulla is white to cream, sometimes with yellowish patches and reacts K+ yellow ( Moncada et al. 2021a). In S. carrascoensis , the medulla is distinctly yellow and reacts K+ lemon-yellow. Sticta andina is widespread in South America and, so far, has been confirmed from numerous localities from Brazil, Colombia and Ecuador and also from Costa Rica, Mexico and in Hawaii ( Moncada et al. 2014a, b, 2020; Widhelm et al. 2018). Thus far, only one collection of S. carrascoensis is known, but it is well-developed and phylogenetically unique, with no close supported relative.

Figures

Figure 1. Best-scoring Maximum Likelihood tree of the Sticta clades I-III containing the new species from Bolivia (blue) and Colombia (orange), based on the fungal ITS barcoding marker. Supported clades are thickened. For a complete tree with individual support values, see Suppl. material 3: Fig. S 1.

Figure 5. Morphology of Sticta carrascoensis (holotype) A, B upper surface with marginal and laminal apothecia C lower surface D apothecia with hirsute margins E tomentum, cyphellae and cilia at the lobe margin F basal membrane of cyphella with papillae. Scale bars: 1 mm (A-E); 10 μm (F).