Chapsa murielongata M.Z. Dou & M. Li, 2021

Dou *, Ming-Zhu, Li *, Min & Jia, Ze-Feng, 2021, New species and records of Chapsa (Graphidaceae) in China, MycoKeys 85, pp. 73-85 : 73

Chapsa murielongata M.Z. Dou & M. Li sp. nov.

Figure 2

Etymology.

The specific epithet murioelongata refers to the elongate, muriform ascospores.

Type.

China. Hainan Province: Ledong County, Jianfengling National Forest Park, 18°42'39"N, 108°52'37"E, alt. 760 m, on bark, 09 Dec 2019, Y. H. Ju HN19222 (LCUF: holotype: HN19222; GenBank MW009102 for ITS and MW010271 for LSU) .

Description.

Thallus corticolous, crustose, olive-grey, surface dull, smooth to uneven, ecorticate. Apothecia erumpent, dispersed or two to four aggregated, rounded, 1-3 mm diam.; thalline margin lobed with white felt-like inner surface, lobes strongly backward curved; disc flesh-coloured, covered by thick, white pruina. Exciple 80-105 μm wide laterally, dark brown; epihymenium 20-40 μm high, with coarse greyish granules; hymenium clear, 110-170 μm high, non-amyloid; hypothecium colourless, 10-30 μm high; paraphyses simple, tips unbranched; periphysoides present, 5-30 μm long. Asci 4-6 (8)-spored, clavate, 100-120 × 35-50 μm; ascospores hyaline, bacillary with rounded to subacute ends, submuriform with 20-25 transverse septa and 0-2 longitudinal septa per segment, 75-105 × 9.5-16 μm, non-halonate, I-. Pycnidia not observed.

Chemistry.

Thallus K-, C-, PD-; no compounds detectable by TLC.

Ecology and distribution.

On the bark in semi-exposed forest of Hainan Province.

Additional specimens examined.

China. Hainan Province: Changjiang County, Bawangling Nature Reserve, Yajia Scenic Area , 10°04'54"N, 109°07'04"E, alt. 810 m, on bark, 08 Dec 2019, Y. H. Ju HN19167 (LCUF) ; China. Hainan Province: Lingshui County, Diaoluo Mountain , 18°43'35"N, 109°52'02"E, alt. 900 m, on bark, 14 Dec 2019, M. Li HN19682 (LCUF) (GenBank MW009103 for ITS and MW010269 for LSU) .

Note.

Chapsa murioelongata is characterised by its olive-grey thallus; white pruinose discs; distinct periphysoids; clear hymenium; 4-8-spored asci; submuriform ascospores with 20-25 transverse septa and 0-2 longitudinal septa per segment. Chapsa microspora Kalb, C. asteliae (Kantvilas & Vězda) Mangold, Astrochapsa elongata Poengs. & Lumbsch and C. patens are morphologically similar to the new species. Chapsa microspora can be distinguished from C. murioelongata by the smaller apothecia (0.6-1.2 mm diam.), transversely septate and smaller ascospores (7-9 × 4 μm) ( Lumbsch et al. 2011). Chapsa asteliae differs in amyloid and shorter ascospores (30-80 μm) ( Kantvilas and Vězda 2000; Mangold 2008). Astrochapsa elongata differs from C. murioelongata in having shorter ascospores (40-65 μm) and less longitudinal septa per segment (0-1) ( Poengsungnoen et al. 2019). Chapsa patens differs from C. murioelongata chiefly in the single-spored asci and broader ascospores (22-35 μm) ( Frisch 2006).

Blast searches of nuLSU sequences indicate Chapsa murioelongata has close affinities with C. patens (98.36% identity), C. wolseleyana (95.63% identity), C. leprocarpa (91.97% identity) and C. indica (90.81% identity), so all these species were included in the phylogenetic analyses. Chapsa murioelongata was well separated from any other species in the tree and strongly supported as the monophyletic (PP = 1; ML = 100%).

Figures

Figure 2. Chapsa murioelongata (LCUFHN 19222) A habit of thallus with apothecia at different developmental stages B apothecium (the pruina of the disc partly scraped off) C section of apothecium with periphysoids (direction of arrow) D paraphyses E an ascus containing six ascospores F ascospore. Scale bars: 3 mm (A); 0.5 mm (B); 50 μm (C); 8 μm (D); 30 μm (E); 25 μm (F).