Buellia alpina Xin Y. Wang & Li S. Wang, 2022

Ai, Min, Li, Li Juan, Worthy, Fiona Ruth, Yin, An Cheng, Zhong, Qiu Yi, Wang, Shi Qiong, Wang, Li Song & Wang, Xin Yu, 2022, Taxonomy of Buellia epigaea - group (Caliciales, Caliciaceae), revealing a new species and two new records from China, MycoKeys 92, pp. 45-62 : 45

Buellia alpina Xin Y. Wang & Li S. Wang sp. nov.

Fig. 5

Diagnosis.

The species is distinguished from its closest relatives B. elegans and B. zoharyi by its linear lobate thallus, heavily pruinose apothecia and lobes, Callispora -type ascospores and four-spored asci.

Type.

China. Xizang Prov.: Lasa Ci., Namucuo Nature Reserve , on soil beside a lake, 30°46'46"N, 90°52'24"E, alt. 4730 m, 28 Sep. 2016, L.S. Wang et al. 16-53720 (KUN-Holotype; SDNU-Isotype) .

Description.

Thallus effigurate, lobate and linear, lobes tightly aggregated, 0.5-1.5 mm wide, prothallus absent; upper surface white to grayish white, dull, covered with granulose pruina; medulla white, non-amyloid (I-). Apothecia sparse to dense, sometimes aggregate, adnate to the thallus, lecideine, margin covered with white pruina which resemble lecanorine apothecia; disc black, roundish, (0.3-)0.5-1.4(-1.6) mm in diam., heavily pruinose, roundish when immature, marginal part becoming wavy and irregular when mature; margin persistent; exciple dispersa -type ( Bungartz et al. 2007), dark brown, without aeruginose pigments (HNO3-); epihymenium brown to dark brown; hymenium hyaline, 80-100 µm tall, without oil droplets, paraphyses simple to moderately branched, apically swollen, with a brown pigment cap; hypothecium dark brown; asci oval-clavate, Bacidia -type, four-spored; spores 1-septate, hyaline when young, turning brown when mature, Callispora -type ( Bungartz et al. 2007), ellipsoid, with tapering ends, proper septum narrow, not thickening during spore ontogeny, (13-)15-20(-22) × (6-)7-9(-10) µm. Pycnidia not seen.

Chemistry.

Thallus K+ yellow, C-, PD-, UV-, medulla I-; containing atranorin.

Distribution and ecology.

This species is mainly distributed in alpine meadows of the Tibetan Plateau, growing on soil within meadows, between elevations of 4700-5000 m.

Etymology.

The epithet " Buellia alpina " refers to the alpine distribution of this species.

Note.

This new species could be distinguished from all other Buellia species by its linear lobate thallus, covered with granulose pruina, black lecideine apothecia with heavy whitish pruina, four-spored asci and its alpine distribution. It might be misidentified as subsquamulose or subfoliose species of Squamarina Poelt, but could be distinguished by the white thickened edges and hyaline simple ascospores.

Specimens examined.

China. Xizang Prov.: Lasa Ci., Namucuo Nature Reserve , on soil beside a lake, 30°46'46"N, 90°52'24"E, alt. 4730 m, 28 Sep. 2016, L.S. Wang et al.16-53737 .

Figures

Figure 5. Morphology of Buellia alpina (16 - 53720 KUN) A thallus on soil within meadow B black lecideine apothecia covered with white pruina C the section of apothecium, exciple dispersa - type D ascospores with 1 - septate, Callispora - type, with tapered ends E mature ascus containing four spores, Bacidia - type F young ascus containing four spores. Scale bars: 2 mm (A); 0.5 mm (B); 50 µm (C); 10 µm (D-F).