Chroogomphus himalayanus K. Das, Hembrom, A. Parihar & Vizzini

Das, Kanad, Vizzini, Alfredo, Parihar, Arvind, Hembrom, Manoj E. & Ghosh, Aniket, 2021, A new species in the genus Chroogomphus (Gomphidiaceae) from India, Phytotaxa 528 (2), pp. 84-92 : 86-90

Chroogomphus himalayanus K. Das, Hembrom, A. Parihar & Vizzini Figs. 2 , 3

MycoBank: MB 830221

GenBank: MK 602359 (nrITS, holotype) and MK 602651 (nrITS, paratype)

Etymology:—refers to the Himalayan mountain range, where the type locality is situated.

Diagnosis:—Differs from similarly looking taxa mainly by the nrITS sequence data and combination of features like robust stipe (130–180 × 15–30 mm), ellipsoid to ellipsoid-elongate basidiospores (12.5– 16.3 –21 × 7.2– 9.6 – 11.8µm), markedly thick-walled hymenial cystidia and occurrence under Abies densa in subalpine Himalaya.

Holotype:— INDIA. Sikkim, East-district, Gnathang, Firing Range Forest , on the soil among mosses, under the trees of Abies , N27°20’53.52” E88°49’06.42”, elev. 3640 m, 3 August 2018, K. Das, KD 18-009 ( CAL 1763 , holotype!).

Description:— Pileus 30–70 mm, conical when young, convex to hemispherical with a prominent central low umbo when mature; surface minutely fibrillose, non-gelatinous, more or less sulcate towards margin, light orange to orange (5A4–6) or brownish orange (6C5) with brownish orange to brown (6C5–D8) at umbo; margin incurved when young, becoming decurved with maturity but often with yellowish white (2–3A2) fibrillose to irregular small velar remnants. Lamellae adnate (broadly attached) to decurrent, somewhat subdistant (5–6 per 10 mm at pileus margin), greyish orange to greyish brown (5B–D3) then more greyish with age; lamellulae in 3 series, concolorous. Stipe 130– 180 × 15–30 mm, cylindrical, broader in the middle part and slightly tapering at base, champagne to corn (4B4–5) or sometimes greyish orange (5B5), more brownish with maturity or on bruising, with some filamentous velar remnants at or near the stipe apex. Basal mycelium white (covering up to 60 mm from the base to apex). Context of the pileus pale orange (5A3) and, pale orange to light orange (5A3–5) in the stipe, unchanging when exposed but turning pale red (8A3) with guaiacol, olive (2E4) with FeSO 4 and dull red (8B3) with 3% KOH. Taste and odour indistinctive. Spore print not obtained.

Basidiospores 12.5– 16.3 –21 × 7.2– 9.6 – 11.8 µm, Q = 1.4– 1.72 – 2.15, boletoid, ellipsoid to ellipsoid-elongate, apiculate, smooth, olivaceous brown to almost dark brown, weakly dextrinoid. Basidia 43–55 × 12–15 µm, septate at base, smooth, mostly hyaline, sometimes pale brown, 2–4-sterigmate, (sterigmata 3.5–11 µm long, broader at base). Basidioles 25–42 × 8–15 µm, clavate, smaller than basidia, septate at base, smooth, hyaline. Pleurocystidia 135–200 × 16–23 µm, cylindrical to subfusiform, thick-walled (wall up to 5 µm thick), smooth, hyaline (in KOH) to pale yellow (in Melzer’s) with dense contents. Cheilocystidia 154–180 × 17–22 µm, thick-walled (wall up to 5 µm thick), smooth, pale yellow (in Melzer’s) to hyaline (in KOH) with dense contents. Hymenophoral trama distinctly amyloid. Pileipellis a trichoderm; terminal elements cylindrical with rounded apex, hyphae, 5–12 µm diam, branched, septate, non-clamped, smooth, non-gelatinised, hyaline; terminal elements cylindrical with rounded apex. Stipitipellis a cutis of hyphae, 4–8 µm diam, septate (mostly), running parallel to stipe surface, densely arranged, some projected anticlinally, smooth, hyaline. Basal mycelium hyphae 3–9 µm diam, mostly septate and sometimes clamped, encrusted with thick amyloid granules to occasionally smooth.

Additional specimen examined (paratype):— INDIA. Sikkim, East-district, Memeinchu , on soil among mosses, under the trees of Abies densa , N27°20’40.1” E88°49’00.1”, elev. 3402 m, 2 August 2018, K . Das, KD 18-076 ( CAL 1764 ) .

Figures

FIGURE 2. Chroogomphus himalayanus (from KD 18-009, holotype).a–c. Fresh basidiomata in the forest and basecamp d. Radial section through pileipellis e–g. Pleurocystidia h–i. Transverse section through lamellae showing cheilocystidia j. Transverse section through a lamella showing basidia k–n. Amyloid hyphae of basal mycelium showing clamp connections and encrustations o. Basidiospores Scale bars: d–e, h–i = 20 µm; f–g, j–o = 10 µm. Photos by: Kanad Das, M.E. Hembrom and Arvind Parihar.

FIGURE 3. Line drawings of the microscopic features of Chroogomphus himalayanus (from KD 18-009, holotype). a. Basidiospores b. Basidia and basidioles c. Pleurocystidia d. Cheilocystidia e. Stipitipellis f. Pileipellis. Scale bars: a–e = 10 µm; f = 25 µm. Drawings by: Kanad Das and M.E. Hembrom.