Helvella sichuanensis X.C. Wang & W.Y. Zhuang

Wang, Xin-Cun, Liu, Tie-Zhi, Chen, Shuang-Lin, Li, Yi & Zhuang, Wen-Ying, 2019, A four-locus phylogeny of rib-stiped cupulate species of Helvella (Helvellaceae, Pezizales) with discovery of three new species, MycoKeys 60, pp. 45-67 : 45

Helvella sichuanensis X.C. Wang & W.Y. Zhuang sp. nov. Figure 3 e–g

Holotype.

CHINA. Sichuan Province, Garzê Tibetan Autonomous Prefecture, Daocheng County, Yading National Nature Reserve, 28°25'6"N, 100°21'26"E, alt. 3900 m, on the ground of mixed forest, 18 Aug 2016, J.P. Wang & X.C. Wang 10706, HMAS 254610.

Etymology.

The species epithet refers to the type locality of the fungus.

Description.

Apothecia stipitate, shallow-cupulate, margin entire and flattened when fresh, undulate, involute or revolute when dry, 5-6 cm diam. when fresh and 2.5-3.5 cm high when dry; hymenium yellowish-brown when fresh, nearly black when dry, receptacle surface buff to light brown when fresh, light brown to dark brown when dry, glabrous; stipe terete or flattened, buff to light brown, surface ribbed, 2.5-3 × 1.5-3 cm when fresh, 2-2.5 × 0.5-1.5 cm when dry, typically fluted with sharp-edged or rarely blunt ribs, ribs branching at the upper half of receptacle surface, reaching to the edge or ending 3-5 mm from the edge. Ectal excipulum of textura angularis, 100-180 µm thick, cells hyaline to light brown, outer cells 15-45 × 9-35 µm. Medullary excipulum of textura intricata, 300-500 µm thick, hyphae hyaline. Asci subcylindrical, tapering and with crozier at base, 8-spored, 225-325 × 13-18.5 µm. Paraphyses filiform with apical portion obviously swollen, septate, hyaline to light brown, 7-10.5 µm wide at apex and 3-4.5 µm below. Ascospores ellipsoidal, hyaline, smooth, uniguttulate, 15.5-18.5 × 10-12.5 µm, median 16.9 × 11.2 µm, Q = 1.3-1.7, median 1.48, n = 40.

Notes.

Helvella sichuanensis belongs to Clade 3 ( Figure 1 ). Its hymenium is nearly black when dry, which is similar to that of H. arctoalpina , but different from those in H. acetabulum (brown when dry) and H. acetabuloides (reddish-brown when dry). When fresh, the hymenium is yellowish-brown, while that of H. arctoalpina is brown. Molecularly, it differs from H. acetabulum in 7 bp of Hsp90 (H410, epitype), 14 bp of ITS2 (HMAS 243823), 17 bp of LSU (H133) and 15 bp of TEF1 (H133); from H. arctoalpina in 1 bp of Hsp90 (H293, holotype), 25 bp of LSU (H033) and 11 bp of TEF1 (H033); and from H. costata in 2 bp of Hsp90 and 13 bp of LSU. The sequence divergences between H. sichuanensis and H. acetabuloides are 1 bp of Hsp90, 20 bp of ITS2 and 12 bp of TEF1.

Figures

Figure 1. Bayesian phylogenetic tree of Helvella and Dissingia inferred from combined Hsp 90, ITS 2, LSU and TEF 1 dataset. Posterior probability values ≥ 0.90 (left) and bootstrap values ≥ 70 % (right) are indicated at nodes.

Figure 3. a-d Helvella acetabuloides: a mature apothecia when dry (CFSZ 2044) b asci (HMAS 23842) c, d ascospores in ascus (c: CFSZ 2044, d: HMAS 23842) e-g Helvella sichuanensis (HMAS 254610): e mature apothecia when dry f mature apothecia when fresh g ascospores in asci h-k Helvella tianshanensis (HMAS 86040): h, i Mature apothecium when dry j asci k ascospores in ascus. Scale bars: 1 cm (a, e); 0.75 cm (h, i); 50 μm (b, g, j); 20 μm (c, d, k).