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

Fig. 2

Diagnosis.

Differing from S. subscrobiculata in the larger thalli with abundant marginal cilia and marginal and laminal apothecia with veined lower surface and the thickness of the upper cortex with 60-80 μm.

Type.

Bolivia. Dept. Santa Cruz; Prov. Florida, Parque Nacional Amboró, above la Yunga Village, senda los Helechos , near view point, 18°02'50"S, 63°54'50"W, elev. 2330 m, Yungas cloud forest with abundant tree ferns, corticolous, 08 June 2011, M. Kukwa 9899 (holotype UGDA, isotype LPB) .

Description.

Primary photobiont a green alga. Stipe absent. Thallus irregular, up to 25 cm diam., moderately branched, with 3-5 branches per 5 cm radius, branching polytomous; lobes ligulate to laciniate, imbricate to adjacent, involute, with their apices rounded to obtuse and involute and their margins entire to sinuous, not thickened; lobe internodes (3-)7-10(-20) mm long, (4-)8-7(-18) mm broad; thallus coriaceous. Upper surface plane to rugose-pitted towards the centre, beige-brown with darker apices in the herbarium, shiny, with the brown marginal line; surface glabrous, without papillae, without pruina, but with irregular to indistinct, cream maculae, present in older parts of lobes; marginal cilia abundant, simple to fasciculated, light to dark brown, rarely white, up to 0.5 mm long. Apothecia abundant, principally submarginal to laminal, sparse to aggregated, subpedicellate, without pronounced invagination on lower side, up to 3 mm diam.; disc light brown to brown (mature) and yellow (young), shiny to matt; margin entire to crenate, hirsute, with brown hairs, abundant in young apothecia, sparse in old ones. Vegetative propagules absent. Lower surface with somewhat elevated, diffuse ridges, cream to brown towards the centre; primary tomentum dense, sparse towards the margin, thick but thinner towards the margin, spongy to fasciculate, soft, light brown to dark brown; secondary tomentum absent. Rhizines scarce, brown to white, up to 8 mm long. Cyphellae 1-20 per cm2 towards the thallus centre and 21-40 per cm2 towards the margin, scattered, rounded to irregular, urceolate with wide pore, erumpent to prominent, remaining below the level of the primary tomentum, with the margin raised and involute, cream-coloured, with tomentum; pore 0.5-1.5 mm diam.; basal membrane pruinose in appearance, white to cream, K+ pale yellow, C-, KC-, Pd-. Medulla lax to compact, white, K-, C-, KC-, Pd-. No substances detected by TLC.

Upper cortex paraplectenchymatous, 60-80 μm thick, consisting of 6-7 cell layers with cells 6-16 μm diam. (with smaller cells in outside parts of the cortex), their walls 3-5 μm thick and their lumina rounded to isodiametric, 4-15 μm diam. Photobiont layer 35-50 μm thick, its cells 5-8 μm diam. Medulla 150-220 μm thick, its hyphae 4-5 μm broad, without crystals. Lower cortex paraplectenchymatous, 30-45 μm thick, with 3-4 cell layers; cells 6-17 μm diam., their walls 2-7 μm thick. Hairs of lower primary tomentum up to 1 mm long, in fascicles of 12-20, hyphae unbranched, 5-6 μm wide with rugose walls, forming a brush-like head with free apices. Cyphella cavity up to 300 μm deep; compacted cells of basal membrane rarely with one papillae. Apothecia biatorine, up to 700 μm high, without distinct stipe; excipulum 125-175 μm broad, laterally with projecting hairs, 50 μm long, simple or in groups. Hymenium 100-110 μm high, K+ yellow; epihymenium up to 20 μm high, yellow-brown, K+ yellow intensifying, with gelatinous upper layer, ca. 5 μm high. Asci 6-8-spored, ascospores fusiform, 1-3-septate, 27-42 × 6-10 μm.

Habitat and distribution.

Sticta amboroensis is known only from one locality in Parque Nacional Amboró in Department Santa Cruz, where it grows on tree bark at altitude 2330 m.

Etymology.

The name refers the Parque Nacional Amboró, where the species was found.

Additional material examined.

Bolivia. Dept. Santa Cruz; Prov. Florida, Parque Nacional Amboró, above la Yunga Village, senda los Helechos , near view point, 18°02'50"S, 63°54'50"W, elev. 2330 m, Yungas cloud forest with abundant tree ferns, 08 June 2011, M. Kukwa 9899a (LPB, UGDA) .

Notes.

Sticta amboroensis forms an isolated lineage not far from other green algal species, such as S. pulmonarioides B. Moncada & Coca and S. subscrobiculata (Nyl.) Gyeln. These species are characterised by a similar morphology, but clearly distinguished phylogenetically. In S. subscrobiculata , the lobes are sparsely branched and pleurotomous and the marginal cilia are sparse to absent, although a cilia-like extension of the lower tomentum is usually visible ( Moncada 2012). In the case of S. pulmonarioides , thallus is smaller, up to 15 cm in diam., with sparse, mainly submarginal apothecia. In addition, the lower tomentum is sparse over the entire lower surface ( Moncada et al. 2013a).

Figures

Figure 2. Morphology of Sticta amboroensis (holotype) A upper surface B lower surface C-D apothecia with hirsute margins E lower tomentum with cyphellae F marginal cilia G cyphella membrane H excipulum in section. Scale bars: 1 mm (A-F); 5 μm (G); 50 μm (H).