Helvella lacunosa Afzelius, 1783, Kongl. Vetensk. Akad. Nya Hand. 4: 303. FIGURE 4
MycoBank number: MB 147441; Index Fungorum number: IF 147441; Facesoffungi number: FoF 02201;
Neotype (here designated): SWEDEN, Lapland, Vindeljallets naturreservat, Gieravard, on the ground, under Betula nana, Salix sp., Dryas sp. forests, 20 Aug. 2010, K. Hansen, K. Gillen & I. Olariaga (KH.10.97).
Pileus irregularly lobed to slightly saddle-shaped, 2–4 cm high, 2–5 cm broad, margin reflexed and fused with stipe; hymenium wrinkled to folded towards the center, taupe or nearly black when fresh, blackish when dry, receptacle surface glabrous, grey to pale greyish when fresh, becoming light blackish when dry. Stipe 3–10 cm long, 1.5–4 cm broad, lacunose, with sharp to rounded ribs, internally chambered, pubescent, taupe, yellowish brown to brownish when fresh, becoming dark brown when dry.
Medullary excipulum 270–330 μm broad, of textura intricata, hyaline, composed of 3–4 μm broad hyphae, blue in cotton blue, J– in Melzer’s reagent. Ectal excipulum 50–110 μm broad, of textura angularis, outermost cells 15–37 × 7–12 μm, catenuliform in long fasciculate tufts, hyaline, evenly blue in cotton blue, J– in Melzer’s reagent. Stipitipellis 60–90 μm, hyaline, composed of cells of textura angularis, terminal cells 13–30 × 7–14 μm, clavate, with a yellow refractive content in Melzer’s reagent, blue in cotton blue. Asci arising from croziers, 8-spored, subcylindrical to clavate, with apex rounded, 230–275 × 14–17 μm, J– in Melzer’s reagent, blue in cotton blue. Paraphyses filiform, 3–5 μm broad, slightly exceeding the asci, with a slightly yellow refractive content in Melzer’s reagent, blue in cotton blue, apex slightly enlarged, 5–7 μm broad. Ascospores [40/2/2, in H2O] (13) 14–16 (17) × 8–11 μm [Q=1.36–1.81, Qm=1.52 ± 0.09)], 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 Betula sp., Salix sp., Dryas sp. forests.
Distribution: Known in Europe (Dissing, 1966; Häffner, 1987) and China (Liu et al, 1985; Zhuang, 2004).
Material examined: CHINA, Tibet, Linzhi County, Lulang Town, alt. 3300 m, 28 Jul. 2014, Qi Zhao 2111 (HKAS 87877), same location, 28 Jul. 2014, Qi Zhao 2112 (HKAS 87878).
Notes: Helvella lacunosa was described by Afzelius (1783), and the type was studied by Abbott & Currah (1997). The distinctive characteristics of our collections, such as irregularly-lobed pileus with a dark brown to blackish hymenium, wrinkled to folded towards the center, a reflexed margin and fusing with stipe in several places, a glabrous, yellowish brown to brownish receptacle surface, and a lacunose, pubescent, yellowish brown, slightly greyish brown to brownish stipe, matches the character variation reported for H. lacunosa (Dissing 1966, Häffner 1987).
Helvella lacunosa has been described and illustrated repeatedly by mycologists worldwide (e.g., Dissing 1966, Weber 1972, Häffner 1987, Zhuang 2004, Abbott & Currah 1997). The relationship and identity of H. lacunosa with other species of Helvella, e.g., H. crispa, H. dryophila, H. fusca, H. juniperi, H. maculata, H. palustris, H. phlebophora, H. pseudolacunosa and H. robusta, H. rugosa, H. sulcata, H. vespertina N.H. Nguyen & Vellinga and H. zhongtiaoensis J.Z. Cao & B. Liu, have been addressed several times (Dissing 1966, Häffner 1987, Abbott & Currah 1997, Nguyen et al. 2013, Ariyawansa et al. 2015).
FIGURE 4. Helvella lacunosa. a, b Mature specimens (a HKAS 87877; b HKAS 87878); c, d Receptacle surface of pileus; e, f Stipitipellis; g, h Asci and paraphyses; i–k Asci; l Ascospores. Scale bars: a, b = 1 cm; c–l = 50 μm.