Oxneriaria pakistanica M.S Iqbal, Usman, K. Habib, Khalid, 2023

Iqbal, Muhammad Shahid, Usman, Muhammad, Habib, Kamran & Khalid, Abdul Nasir, 2023, Oxneriaria pakistanica sp. nov. (Megasporaceae, Pertusariales, Ascomycota) from Darel Valley, Gilgit Baltistan, Pakistan, Phytotaxa 579 (2), pp. 125-131 : 128-130

Oxneriaria pakistanica M.S Iqbal, Usman, K. Habib, Khalid sp. nov.

MYCOBANK MB 845095

Etymology: The epithet ‘ pakistanica ’ refers to the type locality of the country Pakistan.

Diagnosis: Oxneriaria pakistanica is differs from its closely related species Oxneriaria rivulicola by having nonzonate, distinctly areolate, grey to whitish grey upper surface, and prothallus absent, immersed apothecia (1–1.5mm), broadly ellipsoid to sub-spherical ascospores (10–18 × 7–10 µm).

Holotype:— PAKISTAN: Gilgit Baltistan , Darel Valley 35° 37’N, 73° 27’E, elev. 1,900 m, on rocks, 21 October 2020, Muhammad Shahid Iqbal DR-42 ( LAH37495 ), (ITS GenBank accession number OP114649 ).

Description:

Thallus: crustose, non zonate, inially placodoid (lobate), becoming non placodoid with age, 5 cm across. Areoles: distinctly areolate, uncracked, 0.5–1.8 mm wide, minute at ages, broadly attached, discrete to rarely contiguous, thinly wrinkled, irregular or angular to irregular elongated, flat to strongly convex. Upper surface: epruinose, dull, whitish grey to grayish, unchanged when wet. Prothallus: not found. Upper Cortex: paraplectenchymatous, two-layered, above brown, below hyaline, 10–25 µm thick, cells 5–10 µm in diam. Algal layer: discontinuous, 30–50 µm thick, photobiont chlorococcoid, cells ± spherical, 10–15 µm in diam. Medulla:, hyphae prosoplectenchymatous, 3–5 µm wide.

Apothecia: frequent, aspiciloid, immersed, covering whole areole, 1–3 per areole, mostly one per areole, become confluent many, rounded to angular, 0.5–2 mm in diam. Disc: 0.5–2 mm in diam, black, dull, plane to weakly concave, irregular to elongated, often with depressions, epruinose. Margins: concolorous to thallus, elevated, thick, continuous, thinly wrinkled. Thalline exciple: 90–120 µm wide. Proper exciple: indistinct. Epihymenium: brown to dark brownish, 20–30 µm thick. Hymenium: hyaline, 100–155 µm tall. Hypothecium: hyaline, 90–170 µm deep.

Paraphyses: moniliform, septate, 2–4 celled capitate, cell 3.5–5.5 µm wide elevated. Asci: clavate, 8-spored, 60–80 × 30–40 µm. Ascospores: simple, hyaline, broadly ellipsoid to sub-spherical, 10–18 × 7–10 µm.

Chemistry: Cortex K+ (yellowish green), C-, KC + (light green) Medulla: all negative TLC: Unknown substance detected

Habit and Habitat:

The recognized collections of new species are from a moist temperate climate, in an open situation exposed to sun and rain, found at the hilly topography of Darel valley with an altitude of 3.843m. In area, summers are warm and clear and the winters are freezing, snowy, and partly cloudy. The specimens were on calcareous sedimentary rocks. Common floral species are trees and shrubs. Pinus gerardiana, Cedrus deodara, Pinus wallichiana , Fraxinus xanthoxyloides . The average annual precipitation in the valley is 100–300 mm, mostly occurring during winter and early spring in the form of snow. Mean temperatures range from -10 °C in winter to +35 °C in summer.

Additional Specimen:— PAKISTAN: Gilgit Baltistan, Darel Valley 36° 38’N, 74° 28’E, elev. 2,000 m, on rocks, 10 August 2022, Muhammad Shahid Iqbal DR-106 ( LAH 37501), (ITS GenBank accession number OP627196 ).

Comments

Morphologically, Oxneriaria pakistanica can be distinguished from the superficially similar taxon Oxneriaria verruculosa in having 0.5–1.8 mm wide areoles (vs 0.5–1mm wide), distinctly areolate (vs often elongate, giving thallus subplacodoid appearance), epruinose (vs. grey pruinose), prothallus absent (vs. sometimes delimited by black prothallus), 0.5–2 mm in diam apothecia (vs. 0.2–0.5 mm), taller hymenium 100–155 µm (vs. 70–80), deeper hypothecium 90–170 µm (vs 20–30 µm), larger ascospores 10–18×7–10 µm (vs 12–17×7.5–9 µm), chemistry unknown substance detected (vs stictic acid, rarely norstictic acid) ( Nimis 2016). Phylogenetically, Oxneriaria rivulicola is close to the Pakistani taxon but can be easil differentiated as the former has zonate thallus, usually lacks distinct aeroles but with radiating cracks, often with a brownish ting and prothallus usually present, apothecia up to 2 mm, chemistry: no substance detected. Nordin et al., (2011). The Pakistani taxon is non - zonate, distinctly areolate, grey to whitish grey upper surface, and prothallus absent, apothecia 0.5–2 mm, chemistry: unknown substance detected.

Another morphological similar taxon to Oxneriaria pakistanica is Oxneriaria dendroplaca , which has also distinctly - areolate thallus but has black Prothallus, elongated marginal areoles, smaller apothecia (upto 0.6 mm), and brown to dark greenish grey thallus, size of ascospores 13.6–[15.7]–19.2×7.9–[8.9]–11.9, whereas the Oxneriaria pakistanica has none elongated marginal areoles, prothallus absent, larger apothecia 1–2 mm and whitish gray to gray thallus, larger ascospores 10–18×7–10 µm.Nordin et al., (2011).

The ITS nrDNA also support the separation of Oxneriaria pakistanica in phylogenetically. The sequence of Oxneriaria nikrapensis is not available in Genbank. Oxneriaria nikrapensis whitish mealy thallus, larger ascospores 20–24 × 15–20 µm and stictic acid detected by TLC. Chesnokov et al., (2018).