Parasola chowii T. Bau & L. Y. Zhu, 2025

Zhu, LiYang & Bau, Tolgor, 2025, Emendation of morphology and infrageneric standards of Parasola (Psathyrellaceae, Agaricales) and its species diversity in China, IMA Fungus 16, pp. e 143796-e 143796 : e143796-

Parasola chowii T. Bau & L. Y. Zhu sp. nov.

Figs 12 d – f , 14

Diagnosis.

Pileus sordid yellow, ochreous to dark red-brown at center and gray or pale gray at margin when mature; basidiospores 11.4–12.0 × 10.0–10.4 × 8.4–9.4 μm, ovoid or broadly ellipsoid, sometimes lemon-shaped in front view, dark red-brown to almost black, germ pore eccentric, 1.7–3.5 μm wide; basidia dimorphic; cheilocystidia 30–75 × 12–27 μm, ellipsoid, sublageniform or constricted-cylindrical; pleurocystidia 34–103 × 10–25 μm, narrow utriform, sublageniform, (sub) cylindrical or clavate.

Etymology.

The specific epithet “ chowii ” is a tribute to the Chinese mycologist Chung-Hwang Chow for his contribution to the study of ontogeny of coprinoid fungi.

Type.

CHINA • Jilin Province, Changchun City, Jingyuetan National Forest Park , 43°78'61"N, 125°44'54"E, 281 m a. s. l., on humus layer of conifer tree, August 26 th 2021, L. Y. Zhu, HMJAU 60358 (Z 21082609, holotype!) .

Description.

Pileus 6–8 × 9–12 mm when still closed, up to 14 mm when mature, at first ovoid or ellipsoid, expanded pileus conical to flattened; dry; sordid yellow, ochreous to dark red brown at center, gray or pale gray at margin, sometimes with slightly brown hue; sulcate-striate up to center. Context extremely thin, almost unseen in membrane part of pileus, somewhat fleshy and up to 0.8 mm in central disc, white to pale gray, odor and taste not distinctive. Lamellae crowded, free and remote from stipe, with a circular empty space which is visible around the apex of the stipe, 1–2 mm in wide, L = 35–41, I = 1–2, first white to beige, then become purple-gray to dark gray, hardly deliquescent with age. Stipe 20–51 × 1–2 mm, cylindrical, hollow, equal or attenuate towards the apex, white, glabrous; with white tomentose at base. Spore print not recorded.

Basidiospores [60, 4, 3] (10.2 –) 11.4–12.0 (– 13.8) × (9.0 –) 10.0–10.4 (– 11.4) × (7.8 –) 8.4–9.4 (– 9.9) μm, Q 1 = 1.06–1.28, Q 2 = 1.22–1.40, av. Q 1 = 1.14, av. Q 2 = 1.28; subglobose, ovoid or broadly ellipsoid, sometimes lemon-shaped, with apical papilla and convex base in front view, flattened, broadly ellipsoid to ellipsoid in side view; smooth, dark red-brown to almost black, with yellow-brown oil droplet; inamyloid; germ pore eccentric, 1.7–3.5 μm wide. Basidia dimorphic, 20–41 × 9–12 μm, sterigma 4–7 μm, clavate, sometimes constricted in middle part, hyaline, 4 - spored, surrounded with 4–7 pseudoparaphyses; subhymenium composed of subglobose, ellipsoid, oblong or cylindrical elements, 10–28 × 7–19 μm. Cheilocystidia abundant, 30–75 × 12–27 μm, ellipsoid, sublageniform or constricted cylindrical, smooth, colorless, thin-walled. Pleurocystidia 34–103 × 10–25 μm, narrow utriform, sublageniform, (sub) cylindrical or clavate, colorless, thin-walled. Lamella trama regular, 3–5 μm wide, hyaline, colorless, thin-walled. Pileipellis a hymeniderm, made up of sphaeropedunculate cells, 33–49 × 15–36 μm, hyaline, with brown hue at base; pileus trama hyphae densely interwoven, thin-walled, hyaline, yellow brown to brown, 3–5 μm wide. Stipipellis hyphae 3–11 μm in wide, hyaline, thin-walled, colorless, thin-walled; hyphae of stipe trama 8–16 μm wide, colorless, thin-walled; caulocystidia unseen. Clamp connection abundant.

Ecology.

Solitary, subfasciculate, or in small groups, grow on coniferous forest or coniferous and broad-leaved mixed forest. Fruiting in August. Currently only known from China

Other specimens examined.

CHINA • Jinlin Province, Changchun City, Jingyuetan National Forest Park , 43°45'40"N, 125°28'11"E, 312 m a. s. l., August 18 th 2022, L. Y. Zhu, HMJAU 60374 ; CHINA • Inner Mongolia Autonomous Region, Tongliao City, Daqinggou National Reserve , 42°47'34"N, 112°10'38"E, 247 m a. s. l., August 23 rd 2022, T. Bau and L. Y. Zhu, HMJAU 64099 .

Notes.

Parasola chowii is morphologically close to Parasola plicatilis , Parasola plicatilis-similis , and Parasola megasperma . Parasola chowii distinguishes itself from the abovementioned species by its subglobose, ovoid or broadly ellipsoid spores (Q = 1.06–1.28) and unique habitat of humus layer of forest of Pinus . Compared with Parasola chowii , basidiospores of Parasola plicatilis are usually narrower, angularly ovoid with five rounded angles or ellipsoid (Q = 1.05–1.80), in Parasola megasperma spores have larger size which could grow up to 17 μm ( Uljé and Bas 1988). Apart from Parasola chowii , the abovementioned species grow in lawns and other grassy places and Parasola megasperma sometimes also grow on horse dung ( Uljé and Bas 1988; Uljé 2005; Szarkándi et al. 2017). Besides, Parasola plicatilis-similis have darker pileus that is honey-colored, ochre-brown when young and still grayish upon ageing with a pale ochre-brown button when mature ( Szarkándi et al. 2017).

Figures

Figure 12. Basidiomata of species in Clade Plicatilis and Clade Misera of sect. Parasola. a – c Parasola tenuissima: a HMJAU 64085, b HMJAU 64086, c HMJAU 64084; d – f Parasola chowii: d HMJAU 60358, e HMJAU 60374, f HMJAU 64099; g – l Parasola neoplicatilis: g, h HMJAU 64087, i HMJAU 64088, j, k HMJAU 60084, l HMJAU 64089; m, n Parasola plicatilis: m HMJAU 60367, n HMJAU 60366; o Parasola megasperma HMJAU 60099.

Figure 14. Basidiomata and microscopic structures of Parasola chowii: a basidiomata (HMJAU 60358), b pileipellis (HMJAU 60358), c basidiospores (HMJAU 60358, 60374, HMJAU 64099), d basidia (HMJAU 60358), e cheilocystidia (HMJAU 60358, HMJAU 64099), f pleurocystidia (HMJAU 60358), g stipitipellis (HMJAU 60358). Scale bars: 1 cm (a); 10 μm (b – g).