Inocybe qiluensis Y.G. Fan, G.H. Liu, Y. Liu, 2025

Liu, Guohao, Fan, Yuguang, Wang, Jianrui & Liu, Yu, 2025, Inocybe qiluensis (Agaricales), a new nodulose-spored species with hygrophanous pileus from Shandong province, China, Phytotaxa 683 (3), pp. 205-217 : 209-212

Inocybe qiluensis Y.G. Fan, G.H. Liu, Y. Liu , sp. nov. Figs. 2 , 3 .

MycoBank: MB 854435

Etymology: Qi and Lu are vassal states in the Pre-Qin Dystanies and now belong to Shandong Province of China, where the new species collected.

Holotype: CHINA. Shandong Province: Haiyang City, Xujiadian Laozhaishan , on the ground in broad-leaved forests dominated by Quercus acutissima Carruth. (1862: 33) , 1 August 2023, Y. Liu, HMLD5366 .

Diagnosis: Basidiomata small, pileus hygrophanous at first and becoming fibrillose-rimose with hygrophanous stripes. Lamellae moderately crowded with 2–3 tiers of lamellulae. Stipe covered with white fibrils at the brownish background, with longitudinal stripes. Basidiospores 5.7–9.0 × 4.0–6.3 μm, polyhedral with a few weak nodules. Hymenial cystidia fusiform to subfusiform, thick-walled, walls yellowish. Most similar to the Indian species I. kapila , but differs from it by the narrower basidiospores, narrower hymenial cystidia, and an ecology often on the ground among moss.

Description:— Basidiomata small to medium-sized. Pileus 22–30 mm, campanulate when young, then convex with a obtuse broad umbo, sub-applanate to applanate with an indistinct and broad umbo when mature, margin depressed to slightly uplifted; surface dry, initially glabrous-hygrophanous around the disc and showing a indistinct radical grooves outwards, rimmed with indistinct white cortina at the margin when young, fugacious, becoming rimulosefibrillose with radially arranged stripes outwards the disc, at times split or strongly split in older specimens; yellowish white (1A2) to beige (1B3) with pallid margin when young, yellowish (1C5) or light reddish brown (7D3) to reddish brown (7E5) or dark brown (6F4) upon maturity. Lamellae adnexed, moderately crowded, ventricose, 3–4 mm in width, distributed with 2–3 tiers of lamenulae of different lengths; light dirty white (1B1) to grayish white (1C1) when young, becoming yellowish brown (6E5) to dark brown (6F7) when mature, edge pallid and fimbriate. Stipe 27–35 mm long, 2–3 mm wide, central, solid, cylindrical with a slightly swollen base; surface covered with silky-fibrillose to furfuraceous fibrils and longitudinal stripes; light brown (6C5) to grayish brown (7C2), pallid towards the apices and bases. Context fleshy in pileus, 0.6–1 mm thick, white (1A1) or slightly brownish (5D5), fibrous and brownish (4D3) or pinkish (6D4) in stipe. Odour indistinct.

Basidiospores [100/4/4] (5.7)6.2– 7.3 –8.5(9.0) × (4.0)4.3– 5.0 –6.1(6.3) μm, Q = (1.15)1.15– 1.46 –1.74 (1.91), Q m ± SD = 1.46 ± 0.162; angular to polygonal with 6–9 indistinct nodules, but the knob at basidiospore apices up to 2.5 μm high, yellowish to yellowish brown in 5% KOH, with one intracellular ellipsoid oily content. Basidia 18–25 × 6–11 μm, slenderly clavate to clavate, occasionally broadly clavate, obtuse at apex, tapered downwards, with oily contents of different sizes, 4- or occasionally 2- spored, sterigmata 3–5 mm length, colorless or slightly yellow in 5% KOH. Pleurocystidia (31)36– 47 –58(65) × (13)15– 18 –23(25) μm (n = 25), abundant, subfusiform to fusiform, apices obtuse to occasionally tapered, with crystals, base tapered into small pedicel, slightly thick-walled, walls 0.5–1 μm thick at the middle but conspicuously thickened (up to 2.5 μm thick) at the apex, colorless with yellowish walls, some with yellow inclusions. Cheilocystidia 31– 49 –65 × 14– 19 –25 μm (n = 25), scattered, resemble pleurocystidia, subfusiform, fusiform, occasionally sub-cylindrical or sub-utriform, walls yellowish, up to 1 μm thick. Cheiloparacystidia 15– 24 × 6–9 μm, rare, clavate, or fusoid to sub-cylindrical, thin-walled, colorless. Caulocystidia absent, but instead of protruding bundles of thin-walled hyphae, 3–7 μm wide, those often septate at stipe apex, terminal cells 18–29 × 2.5–6 μm, thin-walled or occasionally thick-walled. Hymenophoral trama 88–125 μm, colorless to yellowish, sub-regularly arranged, hyphae 7–15 μm, inflated, smooth, thin-walled, colorless in 5% KOH. Pileipellis a cutis of two layers, 75–114 μm thick, the upper layer 45–60 μm thick with interwoven hyphae around the disc, elsewhere 20–35 μm thick, sub-regularly arranged, colorless, hyphae cylindrical, 3–12 μm wide, smooth; sublayer yellowish-brown to brown in mass, sub-regularly arranged, hyphae inflated, 5–19 μm wide, encrusted with brownish pigments. Pileal trama regularly arranged, colorless or pale yellow, composed of inflated hyphae measured 17–20 μm wide, smooth, colorless, sometimes pale yellow, thin-walled. Stipitipellis a cutis, hyphae 2–5 μm wide, regular, thin-walled, encrusted, yellowish. Oily hyphae mostly in stipe, occasionally in pileal and lamellar trama, 5–13 μm wide, often with nodules, pale yellow to yellow. Clamp connections present in all tissues.

Habitat and ecology:— Solitary in mixed forests or broad-leaved forests dominated by Q. acutissima .

Distribution:— China (Shandong).

Additional specimens examined:— CHINA. Shandong Province: Zibo City, Lushan, in broad-leaved forests dominated by Q. acutissima , 4 September 2011, Y. Liu, HMLD1785. Wulian City, Wulian Mountain, in broad-leaved forests, 4 August 2011, Y. Liu, HMLD1607. Linyi City, Mengshan, in mixed forest, 6 September 2010, T. Bau, HMLD555. Haiyang City, Yunding forest park, in broad-leaved forests dominated by Q. acutissima , 24 July 2010, Y. Liu, HMLD1196.

Remarks:— The new species is characterised by the hygrophanous pileus when young and a sub-hygrophanous disc when mature, whitish silky-fibrillose to furfuraceous stipes with a pinkish to brownish background, small polyhedralnodular basidiospores, fusiform to subfusiform hymenial cystidia, and bi-layered pileipellis. The epicutis is translucent and consists of thin-walled, septate, cylindrical, but not gelatinous hyphae. Interestingly, the hyphae arrangement and thickness of the epicutis is not always consistent. In the center of the pileus, the epicutis is conspicuously thicker and is composed of interwoven hyphae; but in other parts of the pileus, the epicutis is a thin layer of regular to subregular hyphae. Inocybe assimilata (Britzelm.) Saccardo (1887: 789) , a widely distributed species shares similar basidiospores and hymenial cystidia, but it has non- or less hygrophanous pileus, darker more robust stipes, and an ecology mostly under coniferous forests ( Stangl 1989, Breitenbach & Kränzlin 2000, Bandini et al. 2017). Inocybe kapila , described from India has smaller basidiomata, more square basidiospores, and utriform hymenial cystidia with thinner walls ( Latha & Manimohan 2017). Inocybe subferruginea and I. cacaocolor , both described from Australia have appressedscaly pileus with monolayered pileipellis, larger basidiospores, and thin-walled hymenial cystidia ( Matheny & Bougher 2017).

Figures

FIGURE 2. Basidiomata of Inocybe qiluensis. a HMLD1607. b–c HMLD5366 (holotype). d–e HMLD1785. Scale bars: 10 mm (a–e). Photos by Y. Liu.

FIGURE 3. Microscopic features of Inocybe qiluensis (HMLD5366, holotype). a–b basidiospores c basidia d pleurocystidia e–f cheiloparacystidia g cheilocystidia h pileipellis on the periphery i pileipellis upper layer hyphae j pileipellis lower layer hyphae k pileipellis around the disc l pileal trama m hymenophoral trama n oily hyphae o extending hyphae in stipitipellis p stipitipellis q stipe trama. Scale bars: 10 μm (a–q). Photos by G.H. Liu.