Hygrophorus aurantiosquamosus H.Y. Huang & L.P. Tang, 2021

Huang, Hong-Yan, Zhang, Wen-Hao, Huang, Ting & Tang, Li-Ping, 2021, Hygrophorus aurantiosquamosus (Hygrophoraceae, Agaricales), a new species of Hygrophorus section Chrysodontes from western China, Phytotaxa 528 (5), pp. 279-289 : 282-283

Hygrophorus aurantiosquamosus H.Y. Huang & L.P. Tang , sp. nov. ( Figs. 2 , 3a, c , 4a, c–d , 5a–c, e–f )

McoBank:— MB 841194

Etymology:—“ aurantiosquamosus ” refers to the pileus being covered with golden yellow squamules.

Diagnosis:—Characterized by its yellowish white pileus covered with golden yellow squamules, a floccose stipe concolorous with pileus, a distinct pileipellis composed of narrow hyphae with inflated terminal elements of various shapes (clavate, cylindrical, lacrymoid to subglobose); slender basidia (48–66 × 7–10 μm), and elongate to subcylindrical basidiospores (9.5–12 × 4–5.5 μm), occurring in Picea forests, and so far, only known from high elevations (above 3000 m) of western China. Hygrophorus chrysodon differs in a lighter yellow pileus, a pileipellis consisting of narrow hyphae without inflated terminal elements, smaller basidiospores (7–9 × 4–5 μm), shorter basidia (38–50 × 6.5–8 μm), mixed Abies and Fagus forest habitat at low elevations (below 2000 m) of Europe.

Holotype:— CHINA. Tibet Province: Qamdo City, Bangda Town , in Picea forest, elev. about 3500–4300 m, 6 August 2013, K. Zhao 317 ( KUN-HKAS 80742 ).

Gene sequences ex-holotype:— OK104067 (ITS); OK104061 (LSU); OK999992 (TEF1).

Description:— Pileus 2.5–7 cm diam., campanulate with an inrolled margin at first, soon broadly convex to plane, pale yellow (1A5–8) to bright yellow (2A4–6) or chrome yellow (2A8), surface viscid when moist, covered with golden yellow (4A3–7) fine squamules and fibrils when dry; context white (4A1). Lamellae decurrent, subdistant, 45–70/cap with 1–2 lamellulae between each pair, off-white, whitish to cream (4A1). Stipe 5–7 cm long, 0.6–1.5 cm diam., cylindrical to subcylindrical, equal or tapered slightly toward the base, yellowish white (1A3–4), concolorous with the pileus, surface dry, yellow (2A6–8) finely furfuraceous; context white (4A1).

Basidiospores [60/3/3] (9–) 9.5–12 (–12.5) × 4–5.5 (–6) μm, Q = (1.88–) 2–2.5 (–2.75), Q m = 2.22 ± 0.19, elongate to subcylindrical, smooth under the light microscope and SEM, thin-walled, hyaline, non-amyloid. Basidia (45–) 48–66 × 7–10 μm, 4-spored, clavate, thin-walled; sterigmata up to 6 μm in length. Cheilocystidia 25–50 × 3–5 μm, thin-walled, hyaline, colorless, scattered, contorted, of irregular shape, narrowly clavate, gradually tapering toward the apex, vermiform, occasionally branched. Pleurocystidia 24–45 × 3–6 μm, thin-walled, hyaline, colorless, scattered, contorted, of irregular shape, narrowly clavate, gradually tapered toward the apex, vermiform. Hymenophoral trama slightly divergent, non-gelatinized, made up of cylindrical hyphae 3–14 μm diam., and inflated elements, up to 18 μm diam., thin-walled, colorless and hyaline; subhymenial layer next to hymenium, non-gelatinized, composed of short elements 5–49 × 3–7 μm, cylindrical, of irregular shape, thin-walled, colorless and hyaline. Pileipellis an ixotrichoderm, consisting of narrow hyphae 1.5–5 μm diam., loosely interwoven, thin-walled, with inflated terminal elements enlarged in various shapes, e.g., clavate to cylindrical, 25–80 × 8–15 μm, lacrymoid, 7–38 × 5–18 μm, and subglobose, up to 25 μm, some subulate, often with yellowish intracellular pigment. Pileitrama made up of hyphae 3–14 μm diam., thin-walled, dense, slightly parallel. Stipitipellis a cutis, composed of hyphae 3–7 μm diam. Floccules made up of compact erect branched hyphae with cylindrical or slender clavate terminal elements 40–65 × 4–6.5 μm, thin-walled, often with yellowish intracellular pigment. Stipititrama made up of hyphae 3–16 (–18) μm diam., thinwalled, arranged in parallel. Clamp connections present in all tissues.

Habit and habitat:—Gregarious or in small groups in Picea forests (possibly Picea brachytyla , P. likiangensis , P. retroflexa , and P. spinulosa ); elev. above 3000 m; appearing in summer (August).

Distribution:—Currently known in Picea forests at high elevations of in western China, such as Qinghai, Sichuan, and Tibet Provinces; possibly also Pakistan (GenBank accession LK022682 ).

Other material examined:— CHINA. Qinghai Province: Qilian County, Zhamashi Town , elev. 3000 m, 21 August 2004, H.A. Wen & M.X. Zhou 4325 (HMAS 132019, GenBank Acc. No.: ITS = OK104064 ) . Sichuan Province: Aba County, Chali Town , elev. about 4000 m, 12 August 2007, Z.W. Ge 1832 (KUN-HKAS 53917, GenBank Acc. No.: ITS = OK104066 ) ; Seda County, Wengda Town, on grazed meadows under Picea - Juniperus forests, 31°43′12″N, 100°43′10″E, elev. 3775–3925 m, 6 August 2005, Z.W. Ge 782 (KUN-HKAS 49277, GenBank Acc. No.: ITS = OK104065 ) .

Figures

FIGURE 2. Basidioma of Hygrophorus aurantiosquamosus. a KUN-HKAS 53917; b, d KUN-HKAS 49277; c KUN-HKAS 80742 (holotype) (a, b, d photo by Z.W. Ge; c photos by K. Zhao).

FIGURE 3. Basidiospores of Hygrophorus aurantiosquamosus and H. chrysodon. a, c from H. aurantiosquamosus (a from KUN-HKAS 80742, c from KUN-HKAS 53917); b, d from H. chrysodon (E00905347). Bars: a–b = 10 μm under light microscope, c–d = 1 μm under SEM. (Photos by: H.Y. Huang)

FIGURE 4. Basidiaandcystidia ofHygrophorus aurantiosquamosusand H.chrysodon.a–bBasidia;c,e Cheilocystidia;d,f Pleurocystidia. a, c–d from H. aurantiosquamosus (a, c from KUN-HKAS 49277, d from KUN-HKAS 80742); b, e–f from H. chrysodon (E00905347). Bars = 10 μm. (Photos by: H.Y. Huang)

FIGURE 5. Microscopic features of Hygrophorus aurantiosquamosus and H. chrysodon. a Lamellar trama; b–d Pileipellis; e–f Floccule on stipe. a–c, e–f from H. aurantiosquamosus (a–c from KUN-HKAS 80742, e–f from KUN-HKAS 49277); d from H. chrysodon (E00905347). Bars: a–b = 100 μm; c–f = 10 μm. (Photos by: H.Y. Huang)