Helvella cystidiata Q. Zhao & K. D. Hyde, sp. nov.  FIGURE 3

MycoBank number: MB 559702; Index Fungorum number: IF 559702; Facesoffungi number: FoF 11345;

Etymology. Cystidiata, named after the inflated ectal excipulum cells.

Holotype: HKAS 78941

Pileus loosely saddle-shaped to irregularly lobed, 1–3 cm high, 1–4 cm broad, margin reflexed and fused with stipe, hymenium slightly wrinkled to rugose, greyish to greyish brown when fresh, becoming brown to blackish when dry, receptacle surface even, grey to greyish brown when fresh, becoming brownish when dry. Stipe 3–5 cm long, 0.5–1 cm broad, lacunose, with rounded-ribs, glabrous, greyish to greyish brown when fresh, becoming brownish when dry, with white mycelium at the base.

Medullary excipulum 90–210 μm broad, of textura intricata, hyaline, composed of 3–4 μm broad hyphae, walls thickened, J– in Melzer’s reagent. Ectal excipulum 60–110 μm broad, of textura angularis, composed of 20–50 × 20–30 μm, subglobose to ellipsoid, inflated cells, hyaline, terminal cells 10–35 × 8–20 μm, blue in cotton blue, J–. Stipitipellis 45–70 μm, of textura angularis, hyaline, terminal cells 8–44 × 5–20 μm, blue in cotton blue, J–. Asci arising from croziers, 8-spored, subcylindrical to clavate, with apex rounded, 200–330 × 13–19 μm, J– in Melzer’s reagent, blue in cotton blue. Paraphyses filiform, 3–5 μm broad, slightly exceeding the asci, apex enlarged, 4–8 μm broad, hyaline, blue in cotton blue, J–. Ascospores [80/2/2, in H2O] 15–18.5 × 9–12 (–12.5) μm [Q = 1.33–1.83, Qm = 1.62 ± 0.86)], ellipsoid, smooth-walled under the light microscope, uniguttulate, with large central globose to broadly ellipsoidal oil droplet. Asexual morph: Undetermined.

Habitat: Scattered or gregarious on the ground, under Pinus yunnanensis forests.

Distribution: Currently only known in southwestern China.

Specimen examined: CHINA, Yunnan Province, Gucheng County, on the ground, under Pinus yunnanensis Franch, alt. 2500 m, 16 Sep. 2012, Qi Zhao 1683 (HKAS 78941, holotype). CHINA, Yunnan Province, Lanping County, on the ground, alt. 2300 m, 16 Aug. 2011, Qi Zhao 1363 (HKAS 74316).

Notes: Helvella cystidiata is characterized by its loosely saddle-shaped pileus with a margin reflexed and fused with stipe, a slightly wrinkled to rugose, greyish to grey brown hymenium, an even, grey to greyish receptacle surface, a lacunose stipe with rounded-ribs, ectal excipulum comprised of ellipsoid to subglobose inflated cells and all tissues J– in Melzer’s reagent.

Morphologically, Helvella cystidiata is similar to H. lacunosa, both sharing a margin flexed and fused with stipe of pileus and lacunose stipe, but the latter differs from the former as pubescent, yellowish brown to brownish when fresh. Ectal excipulum cells catenuliform in long fasciculate tufts (Afzelius 1783). Phylogenetically, Helvella cystidiata is allied with H. pseudolacunosa with moderate statistical support. However, the latter species has a pinched hymenium, a creamy receptacle surface and a lacunose stipe with enlarged base (Ariyawansa et al. 2015).

FIGURE 3. Helvella cystidiata (HKAS 78941, holotype). a–c Mature specimens (a, b HKAS 78941, c HKAS 74316); d Receptacle surface of pileus; e, f Stipitipellis; g, h Asci and paraphyses; i–k Asci; l Ascospores. Scale bars: a–c = 1 cm; d–h = 50 μm.