Rhizoplaca pachyphylla 2020

Rhizoplaca pachyphylla (H. Magn.) Y. Y. Zhang, comb. nov 2020

MycoBank No: 832201

Holotype Lecanora pachyphylla H. Magn., Lichens from Central Asia 1: 120–121 (1940) (Basionym) ≡ Squamarina pachyphylla (H. Magn.) J.C. Wei, Enumeration of Lichens in China: 232 (1991).Type: China, Gansu Province, 3800–3850 m elev., on rock, 1932, Birger Bohlin (S–Holotype!).

Morphological description 

Thallus saxicolous, areolate without lobate margin, to 4 cm across, to 5 mm thick; areoles continuous, plane to slightly convex, 1–2 mm across; upper surface yellow, densely shallow rimose; lower side with thick, grey to white hypothallus. Upper cortex uneven, filled with yellowish-brown granules dissolving in KOH, 32–48 μm thick, algal layer continuous, variable in height, 80–128 μm; medulla very thick, filled with grey to pale brown granules; lower cortex lacking.

Apothecia common, usually densely grouped, irregular in shape, up to 5 mm in diam.; disc black, pruinose at the centre, plane when young, strongly concave with age; thalline margin thin and crenate, strongly bending towards inside with age; hymenium colourless, I+ blue, ca. 50 μm high; epihymenium containing yellowish-brown granules, ca. 9.5 μm high; subhymenium and hypothecium colourless; paraphyses evenly septate, simple, 2–3 μm in diam., apex more or less swollen and bluish-green, ca. 4.5 μm in diam.; ascus Lecanora-type, 8-spored; ascospores regular in shape, ellipsoid, colourless, 5.8–8 × 3–4.5 μm. 

Habitat: on rock

Distribution: Growing on rock at elevations of 3291–3909 m. Only known from Gansu Prov., China.

GenBank Accession: nrITS ) MK778048\ ) MK778047\ ) MK778049\ ) MK778050 nrLSU na\na\na\na  RPB1MK766417\ MK766416\ MK766416\ MK766419 RPB2 MK766436\ MK766435\ MK766437\ MK766438 mtSSUMN192152\ MN192151\ MN192153\ MN192154

Notes: The holotype grows on rock with Lecidea tessellata Flörke, Lecanora asiatica H. Magn. and Xanthoria elegans (Link) Th. Fr. and contains numerous apothecia.

Reference: : Zhang Y-Y, Wang X-Y, Li L-J, Printzen C, Timdal E, Niu D-L, Yin A-C, Wang S-Q, Wang L-S (2020) Squamarina (lichenised fungi) species described from China belong to at least three unrelated genera. MycoKeys 66: 135–157. https://doi.org/10.3897/mycokeys.66.39057

Figure 3. Rhizoplaca callichroa (A–D KUN-L 19-62900): A habit B apothecial anatomy (LCB) C ascus and spores (Lugol’s) D section of pycnidia (LCB). R. pachyphylla (e–h KUN-L 18-59446): e habit F section of apothecia G ascus and spores (LCB) h section of thallus (LCB). Scale bars: 100 μm (B, F, h); 10 μm (C, G); 20 μm (D).