Urnula auricularioides S. A. Chen, D. Li & G. F. Mou, 2025

Liu, Jin Rong, Li, Deng, Chen, Si Ang, Zhang, Yan Cheng, Mou, Guang Fu, Liu, Yan, Zhou, Guang Rong, Tan, Zhou Rong & Zhang, Jian Hua, 2025, Species diversity and systematic taxonomy of Sarcosomataceae (Ascomycota, Pezizales), with an emphasis on subtropical regions of China, MycoKeys 121, pp. 21-65 : 21-65

Urnula auricularioides S. A. Chen, D. Li & G. F. Mou sp. nov.

Figs 13 , 14 , 15

Etymology.

The specific epithet “ auricularioides ” refers to the appearance and habitat of this species similar to Auricularia species.

Diagnosis.

Differs from other known Urnula species by the combination of the following features: external surface velvety to warty and with ridges, hymenium surface with verrucose bulges to intestinal folds when mature, two types of external hairs composed of strongly encrusted true hairs and smooth, slender short hairs, ellipsoid to bean-shaped, smaller ascospores (25–30.5 × 9–11 μm).

Holotype.

China • Fujian Province, Fuzhou City, Minhou County, Sandiejing National Forest Park , 26°26'N, 119°17'E, ca 550 m alt., on rotten fallen sticks or wood surrounded by mosses on riverside in moist forest mixed with evergreen broad-leaved trees and bamboo, 9 Nov. 2023, S. A. Chen (CSA – 455, IBK, holotype!) (ITS: PQ 489315 ; LSU: PQ 187431 ; rpb 1: PV 247123 ; rpb 2: PV 296008 ; tef 1-α: PV 296003 ).

Description.

Ascomata small to medium-sized, subsessile to distinctly stipitate. Apothecium cupulate, bowl-shaped to long funnel-shaped, up to 15–60 mm in diameter, 20–30 mm in high; margin entire and involute. Hymenium surface glabrous, initially without ornamentation or wrinkled, with verrucose bulges to intestinal folds at maturity, burlywood (3 E 8), yellowish-brown (4 D 8) to rosy brown (6 E 8), lighter in margin, color unchanging when bruised, darkening and cracked after drying. External surface velvety, densely dotted with droppable and fine grey (9 D 1) warts, with radial and forked ridges or crests not reaching margin, tapering towards the base or stipe, slate grey (12 D 1), dim grey (21 D 1) to off-black (4 F 8), covered by subiculum. Stipe (when present) up to 5 mm in diameter, 19 mm in high, uneven or foveolate, concolor with the external surface. Subiculum off-black (4 F 8), mussel base byssal-like, dense, soft, and fibrous, mixed or flexuous. Flesh thin, gelatinous, elastic, coco-nata white (1 A 1). Odor and taste not special. Anamorph not observed.

External hairs mainly of two types, although intermediates forms may exist: 1) short, hyphoid, septate, cylindrical, slightly to distinctly curved or flexuous, subhyaline with a very pale yellow tint but occasionally dark brown (5 E 8) to dull black (18 F 8) for a granular intracellular pigment in part, thin-walled, 2–4 μm in diameter, subcylindrical, tips rounded to slightly subcapitate, surface smooth (Figs 14 b , 15 e ); 2) long, true hairs, undulated, almost non-septate, some branched, tips rounded to truncated, surface unevenly covered by a granular to agglomerate encrustation, 4–7 μm in diameter, with moderately thick walls, up to 1 μm thick, light brown (4 C 7) or grayish olive (29 D 5) to dark brown (5 E 8) and off-black (4 F 8) (Figs 14 c , 15 f ). Ectal excipulum of a textura subglobulosa to textura angularis, textura irregularis made up of properly thick-walled (up to 4 μm) cells up to 5–35 μm in length and / or width, tawny (4 C 5) to dark brown (5 E 8) and dull black (18 F 8), not or slightly encrusted, 95–240 μm thick (Fig. 14 f ). Medullary excipulum of a loose textura intricata immersed in a highly gelatinous matrix, approximately 260–510 μm thick (Figs 14 e , 15 h ), mainly with two types of hyphae: I) short, septate, subhyaline or pale yellow (1 A 5), thin-walled, arboriform and flexuous, 2–3.5 μm in wide; II) long (relative to type I), septate, concolor with type I hyphae, thin-walled, cylindrical, almost no branched, roughly parallel to subhymenium, 1.5–3 (5) μm in wide. Subhymenium of a dense textura intricata of closely septate hyphae, surface smooth, up to 3 μm in diameter, thick-walled, tawny (4 C 5) to light brown (4 C 7), dark brown (5 E 8) at low magnification, 50–220 μm thick (Fig. 14 d ). Asci cylindrical, operculate, with a tapered or attenuated base, rounded at apex, 8 - spored, 240–410 × 11–18 μm, non-amyloid (Figs 14 g – i , 15 a ). Ascospores uniseriate, smooth, sometimes curved, thick-walled, rounded at both ends, heterogeneous in shapes depending on the spacial position and growth stage of the spores, pale yellow (1 A 5) or chartreuse (30 A 7) to grayish olive (29 D 5), incipiently ellipsoid to allantoid with walls up to 3 μm thick, becoming oblong to bean-shaped with walls 1–2.5 μm thick, [40 / 4 / 2] (23.5) 25–30.5 (32) × (8.5) 9–11 (11.5) μm, Q values = (2.31) 2.46–3.1 (3.3), non-amyloid, with 0–5 lipid bodies (Figs 14 i, k, l , 15 c ). Paraphyses filiform, not or slightly extending the length of asci, septate, cylindrical, straight to slightly curved, dark coffee brown (4 E 8) due to the extracellular amorphous pigments, darkening toward the upper part but deposited by dense off-black (18 F 8) pigments near the base, (1) 1.5–2.5 μm in diameter, tips rounded to finger-shaped, sometimes branched 1–3 times (Figs 14 m, n , 15 d ). Hymenial hairs abundant, cylindrical, long as the paraphyses, non-septate, 2.5–3.5 (4.5) μm in diameter, concolor with the paraphyses due to the homogeneous pigments, agglutinating or intermingle with the paraphyses to bundles, tips rounded to slightly subcapitate, straight, curved, or flexuous to almost hooked (Figs 14 o , 15 b ). Subiculum grayish olive (29 D 5), tawny (4 C 5), and rosy brown (6 E 8) to dark brown (5 E 8), septate, with a slightly thick wall, up to 1 μm thick, slightly curved, unbranched, not or slightly encrusted by an extracellular dark brown (5 E 8) to dull black (18 F 8) pigment, (2) 4.5–6 μm in diameter (Figs 14 p , 15 g ).

Habitat.

Growing in gregarious groups on rotten fallen branches or twigs surrounded by mosses on riverside, half-buried in the litter layer in moist forest mixed with evergreen broad-leaved trees and bamboo.

Geographic distribution.

So far, only known from Fujian Province, China.

Other material examined.

China • Fujian Province, Fuzhou City, Minhou County, Sandiejing Forest Park , 26°26'N, 119°17'E, ca 550 m alt., 9 Nov. 2023, S. A. Chen, CSA- 454 ( IBK!) (ITS: PQ 489472 , LSU: PQ 187433 ; tef 1-α: PV 296002 ) .

Notes.

Urnula auricularioides is morphologically similar to Urnula versiformis , sharing most characteristics but distinctly differing from the latter by its slender external short hairs (2–4 μm in wide vs. 5–7 μm in wide) and small ascospores (25–30.5 × 9–11 μm vs. 30–35 × 10–12 μm) ( Wang and Huang 2015). U. auricularioides is also similar to U. campylospora and U. ailaoshanensis in morphology. However, U. campylospora produces reticulate external surface and two-typed external hairs composed of heavily encrusted short hairs (5–6 μm in wide) and mainly smooth true hairs ( Carbone and Agnello 2013), while U. auricularioides is evidently distinguished by its ridged external surface and smooth, slender external short hairs (2–4 μm in wide) and strongly encrusted true hairs; U. ailaoshanensis characteristically produces reticulate external surface and one-typed external hairs ( Lu et al. 2023). In the phylogenetic analysis, Urnula auricularioides is relatively close to Urnula himalayana , but it can be easily separated on multiple morphological characteristics. U. auricularioides produces entire margin, smooth and slender external short hairs (2–4 μm in wide vs. 6–7 μm in wide), and smaller ascospores (25–30.5 × 9–11 μm vs. 24–33.6 × 10–13.8 μm). Additionally, the external surface appearance of both species is also clearly different. U. himalayana has a reticulate pattern without warts formed by vertically joined folds or veins ( Wang et al. 2018), whereas U. auricularioides possesses a ridged surface covered with vertical folds or crests with visible warts.

Figures

Figure 13. Ecological and macroscopic characteristics of Urnula auricularioides, photos by S. A. Chen; b, d, e, f, g. from holotype CSA- 455 (IBK!); c, h. from CSA- 454 (IBK!). a. Habitat where the specimen grew, a moist forest mixed with evergreen broad-leaved trees and bamboo on riverside; b, c. Fresh ascomata with a hymenium surface that is unfolded when immature and variously wrinkled when mature, growing on rotten branch surrounded by mosses; d, f. Dried materials; g. Hymenium surface with dense verrucose bulges; h. Velvety external surface of fresh specimens with greyish warts. Scale bars: 10 mm (b – h).

Figure 14. Microscopic structures of Urnula auricularioides, photos by S. A. Chen, from holotype CSA- 455 (IBK!). a. Cross section through apothecia; b. Type 1 of external hairs; c. Type 2 of external hairs; d. Hymenium and subhymenium in Congo red; e. Medullary excipulum with two types of hyphae (type I indicated by black arrows; type II indicated by white arrows) in Congo red; f. Ectal excipulum and external hairs in Congo red; g. Asci with mature and immature ascospores; h. An ascus with 8 developed ascospores in Meltzer’s reagent; i. Apical apparatus of ascus in Congo red; j. Ascospore in distilled water; k. Ascospore in Meltzer’s reagent; l. Ascospore in Congo red; m. Straight to hooked hymenial hair and paraphyses; n. Tips of paraphyses in Congo red; o. Hymenial hair in Congo red; p. Hypha of subiculum. Scale bars: 100 μm (a); 50 μm (g, o, p); 20 μm (b, d – f); 10 μm (i – n).

Figure 15. Microscopic structures of Urnula auricularioides, drawing by S. A. Chen, from holotype CSA- 455 (IBK!). a. An ascus with 8 developed ascospores; b. Hymenium hairs; c. Ascospores; d. Paraphyses; e. Type 1 of external short hairs; f. Type 2 of external long hairs; g. Hypha of subiculum; h. A part of ectal excipulum. Scale bars: 50 μm (a); 20 μm (b, d, f, g, h; b, d sharing the same bars); 10 μm (c, e).