Gliophorus calunus L. A. Re, D. Tighe, W. Cardimona, M. Hackney & Leal-Dutra 2026, sp. nov.

Gliophorus calunus L. A. Ré, D. Tighe, W. Cardimona, M. Hackney & Leal-Dutra sp. nov. Fig. 6 Etymology. Cal – for California where the holotype and most of the additional collections were found by the California Fungal Diversity Survey and unus – Latin for one, referring to the number one in the provisional name for this species. Diagnosis. Pileus glutinous, margin usually inrolled, Pearl Gray, Light Drab to Drab, Dark Drab, Cinnamon or Tawny Olive at centre, usually paler towards margin. Stipe viscid with horizontal bands of contrasting translucence. Resembling Gliophorus subaromaticus from the same north-western North American coast to coastal range conifer forests, but differs in pileus centre usually with Drab tones vs. Buff to Olive-buff or buffy-brown tones, lamellae bright blue vs. white under UVf 365 nm, pileus margin usually inrolled vs. straight and lacking an odour vs. usually with a disagreeable odour. Holotypus. USA • California, Mendocino Co., Jackson Demonstration State Forest, 39.4045, -123.7537 (accuracy 12 m), ca. 140 m a. s. l., 22 Dec 2023, D. Tighe, (voucher HAY: F-012170 [California State University East Bay Fungarium], iNaturalist: 194601188, holotype) (GenBank ITS: PQ 619233). UNITE / PlutoF: SH 0910864.10 FU (1.5 % threshold). Description. Pileus 6–24 mm diam., convex to broadly convex with an incurved margin, becoming plane or nearly so, sometimes with an umbo, colour Pearl Gray in type, Light Drab to Drab, Cinnamon or Tawny Olive, usually paler towards margin, strongly viscid to glutinous especially when young, margin often translucent-striate. Stipe 20–60 × 3–9 mm, often concolorous with the pileus, slimy viscid, horizontal bands of contrasting translucence (marbled), glabrous, equal or slightly tapered at base, some slightly curved or nodulose; context hollow. Lamellae sinuate or slightly arcuate, white, sometimes tinted pale grey or drab, 1–2 (– 3) lengths lamellulae inserted, bright blue under UVf 365 nm. Taste and odour indistinct. Basidiospores hyaline, ellipsoid, (6.7 –) 7.5–9.6 (– 10.8) × (4.1 –) 4.4–5.5 (– 6.5) µm, mean Q = 1.7–1.8 in the holotype and iNaturalist: 148430507 from northern California, (6.1 –) 6.5–8.6 (– 9.6) × (4.1 –) 4.3–5.2 (– 5.6) µm, mean Q = 1.6 in iNaturalist: 1102000323 from Olympia in northern Washington. Basidia 4 - sterigmate, with typical (non-toruloid) basal clamp connections. Cystidia absent on lamellae. Hymenophoral trama subregular. Pileipellis and stipitipellis an ixotrichoderm, with slender embedded hyphae lacking toruloid clamp connections. Habitat. Holotype growing on a mossy sandbank amongst grasses, sedges and cattails, near Vaccinium ovatum and Notholithocarpus densiflorus. Typically found in coastal Cupressaceae - dominated forests (coastal redwood, Sequoia sempervirens and western red cedar, Thuja plicata), often mixed with hardwoods and other conifers (western hemlock and Douglas fir). Geographical distribution. Occurs in coastal forests of western North America, recorded from northern California and western Washington State, USA, but likely occurring throughout coastal Cupressaceae - dominated forests in western North America, especially Thuja plicata. (Fig. 5 A). Additional specimens examined. USA • (1) California, Humboldt Co., Eureka Area, Headwaters Forest Reserve, Headwaters Forest Trail, 40.6897, -124.1309, ca. 45 m a. s. l., under redwood (Sequoia) and alder (Alnus), Feb 2023, M. Hackney, iNaturalist: 148430507, ITS: OR 593565 (HAY-F-000642); (2) Washington, Thurston, County, N of Olympia, W of South Bay, 47.0738, -122.9012, ca. 10–20 m a. s. l., 22 Nov 2021, L. Ré & S. Hickey (iNaturalist: 102000323). Additional sequenced specimens with photographs. USA • (1) California, Humboldt Co., Trinidad, Strawberry Rock Trail, 41.0790, -124.1313 (187 m accuracy), ca. 190 m a. s. l., 17 Nov 2023, N. Siegel CSALVA 37, northern Franciscan (coastal) redwood forest, (NS 1093, UCSC); (2) Marin Co., Bolinas, Bolinas Fairfax Rd., 37.9404, -122.6577, ca. 45 m a. s. l., under coastal redwood (Sequoia sempervirens), Tanoak (Notholithocarpus densiflorus) and Vaccinium spp., 6 Jan 2024, D. Tighe, iNaturalist: 195986180, ITS: PQ 619243, (HAY-F-012180); (3) ibid., Mendocino Co., Jackson Demonstration State Forest, near Caspar Orchard Rd., 39.3606, -123.7787, ca. 110 m a. s. l., under coastal redwood (Sequoia sempervirens), western hemlock (Tsuga heterophylla), evergreen huckleberry (Vaccinium ovatum) and tanoak (N. densiflorus), 19 Jan 2025, D. Lyons, iNaturalist: 259023907, ITS: PV 520938 (HAY-F-013708); (4) ibid, San Mateo Co., SW of Redwood City, 37.4700, -122.27 (28.4 km accuracy), Jan 2025, Y.-M. Wang, iNaturalist: 260206232; (5) ibid., Santa Cruz Co., Santa Cruz, Henry Colwell Redwoods State Park, 37.0195, -122.0436, ca. 160 m a. s. l., 13 Feb 2023, D. Lyons, iNaturalist: 148743563, ITS: PQ 822173 (OMDL 11). (6) Washington, King Co., Auburn, 188 th Ave. SE, 47.2675, -122.0914, ca. 45 m a. s. l., 31 Oct 2023, Y.-M. Wang, iNaturalist: 189684363 (PSMS 1465); (7) ibid., Mason Co., near Little Skookum Inlet and SE Lynch Rd., 47.1480, -123.0630, ca. 10–20 m a. s. l., 2 Dec 2024, S. Ness, iNaturalist: 253949042 (OLY-0918); (8) ibid., Thurston, County, N of Olympia, W of South Bay, 47.06976, -122.89716, ca. 20 m a. s. l., 25 Nov 2023, B. Funkhouser, iNaturalist: 192129100; (9) ibid., Boston Harbor, near Boston Harbor Rd. NE and Bromley Ln NE, 47.13150, -122.89779, 8 m accuracy, ca. 10 m a. s. l., 25 Dec 2024, M. Koons, iNaturalist: 256218784. Notes. Gliophorus calunus resembles G. subaromaticus, but differs in pileus centre usually with Drab tones vs. Buff to Olive-buff or buffy-brown tones, lamellae bright blue vs. white under UVf 365 nm, pileus margin usually inrolled vs. straight and lacking an odour vs. usually with a disagreeable odour. Both species occur in north-western North American coastal forests dominated by Cupressaceae, with G. calunus growing from soil beneath both Sequoia sempervirens and Thuja plicata, whereas G. subaromaticus has hitherto only been recorded under S. sempervirens. G. calunus appears to be a more widespread and abundant species (Fig. 5 A, B). The pileus of G. fumosus, hitherto only collected in eastern North America, but with eDNA sequences extending into western North America (Fig. 5 D), is usually tinted more greyish-brown and differs in having a straight margin. Coastal conifer forests where G. calunus likely occurs in north-western North America are currently threatened by heavy logging. We suggest California Slimy Waxcap as the common English name for this new species.