Pleopsidium corrugatulum C. C. Miao, Xin Y. Wang & Li S. Wang sp. nov.

Figs 4, 5

Type.

China. • Qinghai Prov.: Xining Ci., 36°33'17"N, 101°54'01"E, alt. 2190 m, 07 Jul. 2023, S. B. Zhang et al. ZSB 23-906 (holotype: KUN; isotype: SDNU).

Diagnosis.

The new species differs from Pleopsidium tumidulum by its wrinkled areoles surface, thinner thalli, shorter lobes, numerous pycnidia, and molecular data.

Description.

Thallus crustose, tightly attached to the substrate, areolate at center, radiate-plicate at margin; areoles rimose, wrinkled, mostly infertile, 1–2.3 × 0.8–1.5 mm; marginal lobes sometimes cracked, 1–3 mm long, 1–2 mm wide, 0.7–1.5 mm thick, tightly attached to the substrate; upper surface yellow or dark yellowish green; upper cortex yellow, 25–50 μm thick; algal layer 100–175 μm thick; medulla white, 100–275 μm thick. Apothecia rare to moderately frequent, one mature apothecium or several young ones in each areola, cryptolecanorine to lecanorine, roundish, 0.9–1.25 mm wide; disc pale yellow, darker than thallus, plane; margin yellow, concolorous with thallus; epihymenium brownish yellow, 25–50 μm thick; hymenium hyaline, 37.5–62.5 μm high; paraphyses simple, with 4–5 septa, apices often expanded; hypothecium hyaline, 50–87.5 μm high; asci clavate, 37.5–55 × 12.5–20 μm, ± 100 - spored; ascospores hyaline, ellipsoidal, aseptate, 5–6 × 2–3 μm. Pycnidia immersed; conidia bacilliform, 2–2.5 × 1 μm.

Chemistry.

Thallus UV + dark orange-yellow, P –, K –, C –, KC –. Containing rhizocarpic acid.

Distribution and ecology.

This species usually grows on exposed rocks in the Gobi, desert steppe, and in bush formations between ca 1290 m and ca 2190 m. It is distributed in the Qinghai, Xinjiang, and Ningxia provinces in China.

Etymology.

The epithet “ corrugatulum ” refers to the wrinkled surface of the species.

Note.

It is characterized by the absence of apothecia in most examined specimens, wrinkled surface, rugose lobes, numerous pycnidia, and absence of fatty acids. Pleopsidium gobiense also lacks fatty acids but frequently develops apothecia with flat surfaces.

Selected specimens examined.

China. • Ningxia Prov.: Yinchuan Ci., Gunzhongkou Scenic Spot, 26 Jul. 2021, Y. J. Zhang ZYJ 1 (KUN); • Helan Mount Nature Reserve, Suyukou Forest Park, 38°44'13"N, 105°57'10"E, alt. 1640 m, 19 Aug. 2015, Abdulla Abbas 20151024 - a (XJU); • Helan Mount Nature Reserve, 38°44'06"N, 105°57'10"E, alt. 1650 m, 13 Aug. 2015, Abdulla Abbas 20151086 - c (XJU). • Xinjiang Prov.: Hami Ci., Balikun Co., G 335, 43°36'09"N, 92°44'45"E, alt. 1639 m, 04 Jul. 2022, L. S. Wang et al. 22-72992 (KUN); • Hami Ci., Balikun Co., Sa’erqiaoke Vil., 43°45'57"N, 92°02'26"E, 04 Jul. 2022, L. S. Wang et al. 22-72341 (KUN); • Fuhai Co., Hongshanzui, alt. 2000 m, 3 Oct. 2000, Abdulla Abbas Po 001003 (XJU); • Yili Region, Altay Qinggou, alt. 1294 m, 17 June 2017, Abdulla Abbas 20130708-1 (XJU).