Sinotermitomyces taiwanensis M. Zang & C.M. Chen

Yang, Kun L., Lin, Jia Y., Li, Guang-Mei & Yang, Zhu L., 2025, New and interesting fungi from Guangzhou City, South China, Phytotaxa 707 (1), pp. 1-95 : 42-51

Sinotermitomyces taiwanensis M. Zang & C.M. Chen , Fungal Science 13(1–2): 25 (1998)

Notes:— Sinotermitomyces M. Zang was proposed to accommodate species similar to Termitomyces R. Heim but mainly distinct in veiled basidiomata with a hollow stipe, and totally six species had been placed in this genus, namely S. carnosus M. Zang , S. cavus M. Zang , S. griseus M. Zang , S. meipengianus M. Zang & D.Z. Zhang , S. rugosiceps M. Zang and S. taiwanensis M. Zang & C.M. Chen ( Zang 1981, 1992, Zang & Chen 1998, Zang & Zhang 2004). Sinotermitomyces cavus was selected as the generic type ( Fig. 15), but has been proven to be a later synonym of Termitomyces heimii Natarajan by morphology and molecular phylogeny, and thus Sinotermitomyces is now synonymized with Termitomyces ( Yang 1990, Wei et al. 2006, Wei et al. 2009, Tang et al. unpublished data). In our earlier work on revision of termitomycetoid fungi from China (Yang et al. 2025), we generally followed Wei et al. (2006, 2009), considered S. meipengianus an ambiguous taxon not belonging to Lyophyllaceae , and the other five Sinotermitomyces taxa either Termitomyces heimii or T. mammiformis , without detailed statements as T. heimii or T. mammiformis were not treated in that work. The selected taxon Sinotermitomyces taiwanensis is discussed below due to its potential relation with Termitomyces intermedius , a common and well-known edible species in Guangzhou City (Yang et al. 2025).

In the protologue of Sinotermitomyces taiwanensis ( Zang 1981) , only one collection, the holotype, was cited. Both the description and line illustration outline a species distinct in a persistent annulus and a distinctly hollow stipe, a characteristic combination known in the T. heimii - T. mammiformis group among species of Termitomyces and its allies in Asia ( Ashraf et al. 2022, Hussain et al. 2024 b, Yang et al. 2025). The photograph cited for this species has no voucher number labeled, and confusingly it shows two basidiomata similar to Termitomyces intermedius in appearance, with their stipe not sectioned, and without a visible annulus on the entire stipe of one basidioma. Wei et al. (2006) re-examined the holotype of Sinotermitomyces taiwanensis , found it consisted of only a half of a basidioma, without trace of a partial veil and both the stipe and pseudorhiza were solid, and they concluded that S. taiwanensis is a later synonym of T. clypeatus R. Heim. Their observation raises the possibility that S. taiwanensis is conspecific with Termitomyces intermedius , as many collections consistent with the concept of T. clypeatus recorded in China have been proven to be T. intermedius with phylogenetic evidence (Yang et al. 2025). However, the significant conflicts among the description and line illustration in the protologue, the photograph in the protologue, and the observation by Wei et al. (2006), imply a possible problem that the holotype originally contained more than one species but was partly lost later, and as far as we know, the holotype (KUN-HKAS30320) originally deposited in the Herbarium of Cryptogams in Kunming Institute of Botany of Chinese Academy of Sciences, could not be found as accessed on April 28, 2025, and is possibly lost. These issues make S. taiwanensis an ambiguous taxon at present.

Porotheleaceae Murrill

Marasmiellomycena entolomatoides Kun L. Yang, Jia Y. Lin & Zhu L.Yang , sp. nov. ( Figs 16–17; Table 9; Supplements 2 and 10)

Registration identifier FN572709

Etymology:— We originally misidentified it as an Entoloma species in the field.

Diagnosis:— Differing from Marasmiellomycena tomentosa by greyish basidiomata and smaller basidiospores.

Type:— CHINA. Guangdong Province: Guangzhou City, Haizhu District, Shangchong Fruit Tree Park , 23°04’36”N, 113°18’21”E, elevation 2 m, June 9, 2023, Jia Y . Lin & Kun L . Yang, K23262 ( HKAS147746 , holotype ( ITS: PV620884 ; nrLSU: PV616947 ); HTBM0777 , isotype) .

Description:— Basidiomata tiny, without a distinct colour change after damaged; odour indistinct; taste unknown. Pileus 3–5 mm in diameter, hemispherical and not depressed at first, becoming plano-convex and depressed at center, merino white (#F9F5EC), light grey (#F1F0F0) to muddy grey (#938F89) or dark heather brown (#9D917B), covered with whitish tomenta. Lamellae decurrent, subdistant, ceramic white (#FEFEFA), with an entire edge, interspersed with abundant lamellulae. Stipe 7–12 mm long, 0.5–1 mm thick, tapering downwards or subcylindrical, more or less curved, concolorous with the pileus, becoming darker downwards, covered with whitish tomenta.

Context composed of a somewhat sarcodimitic ixoplect in stipe, elsewhere almost showing a holomonomitic thigmoplect to ixoplect. Basidiospores {40/3/2} 5.5–7 (7.5) [6.34 ± 0.53, 6.00] × 3–3.5 (4) [3.33 ± 0.29, 3.50] µm, Q = 1.71–2.17 [1.91 ± 0.13, 2.00], oblong, with thin eusporium, smooth, often agglutinated together by myxosporium, nearly colourless, with a small apiculus. Basidia 20–32 × 5.5–7 μm, clavate, four-spored, thin-walled, nearly colourless. Lamella trama subregular to irregular, composed of 2–20 µm wide, thin-walled to slightly thick-walled, nearly colourless, compact, moderately to frequently branching hyphae. Cheilocystidia absent. Pleurocystidia absent. Pileipellis composed of a rectocutis by 2–5 µm wide, thin-walled to slightly thick-walled, slightly brownish, compact, rarely to moderately branching hyphae, issuing sparsely distributed, oblique to erect, lageniform, nearly colourless, thin-walled to slightly thick-walled pileocystidia up to 350 µm long, 1–3.5 µm wide. Stipitipellis similar as the pileipellis. Clamp connections abundant.

Habit and distribution:— Gregarious, on dead branches, in subtropical orchards. Currently known from China.

Other collections examined:— CHINA. Guangdong Province: Guangzhou City, Haizhu District, Shangchong Fruit Tree Park , 23°04’36”N, 113°18’21”E, elevation 2 m, August 3, 2024, Jia Y . Lin, L24216 ( HTBM2201 ), L24217 ( HTBM2202 ), L24218 ( HTBM2203 ) & L24219 ( HTBM2204 ) .

Phylogeny:— According to the BLAST search of ITS sequences in GenBank ( NCBI 2025), our collections HKAS147746, HTBM2201, HTBM2202 and HTBM2204 represent a single species of Porotheleaceae uncertain in generic level. Therefore, a phylogeny was inferred to classify our collections with representative collections of known genera in Porotheleaceae and our collections as the ingroup, and a collection of Cyphellaceae as the outgroup according to a recent study on phylogeny of Agaricales ( Wang et al. 2023) , using two loci (ITS & nrLSU) available for most species in this group ( Table 9; Supplement 10). In the result, the ML and BI topologies are almost identical, only with a minimal variation in statistical support, so only the tree inferred from the ML analysis is displayed ( Fig. 16). Our collections HKAS147746, HTBM2201, HTBM2202 and HTBM2204 and an orchid mycorrhizal isolate (OTU35) form an undescribed clade with significant support, inside a moderately supported clade that can be classified as Marasmiellomycena .

Notes:— Our collections of this fungus were all found on dead branches of Hibiscus tiliaceus ( Malvaceae ). No orchids were found growing near the collection site of this fungus. However, as suggested by the conspecific clusting of an orchid mycorrhizal isolate (labeled as OTU35, generated from Xing et al. 2019), this species may be a rhizosphere fungus of orchids. More details on its role are unknown.

The genus Marasmiellomycena is characterized by omphaloid to marasmioid basidiomata with more or less pruinose to tomentose pileus and stipe as compared with its closely related genera ( Senanayake et al. 2023). Marasmiellomycena entolomatoides generally conforms its concept.

The ITS and nrLSU sequences of taxa in Porotheleaceae seem to exhibit a high evolutionary rate ( Fig. 16). In the recent scale of genus recognition in this family, it looks feasible to split the clade recognized as Marasmiellomycena in the current phylogeny ( Fig. 16) as three separate genera following the inner nodes with higher support values. However, such a treatment will result in two new genera in monotypic status, and thus we suggest to re-consider this issue with data from more loci in the future.

The structure of lamella trama was reported as pachypodial in some species of Porotheleaceae ( Clémençon 1982) , but is not observed in M. entolomatoides . Sarcodimitic tissues may be a characteristic of Porotheleaceae ( Redhead 1987) , but are also not distinct in M. entolomatoides .

Boletales E.-J. Gilbert

Boletaceae Chevall.

Floriboletus Kun L. Yang, Jia Y. Lin & Zhu L. Yang , gen. nov. ( Figs 18–19; Table 10; Supplements 2 and 11) Registration identifier FN572710

Etymology:— Referring to the gorgeous pileipellis, and also the type locality (Guangzhou City, aka. Flower City).

Type:— Floriboletus tianheensis Kun L. Yang, Jia Y. Lin & Zhu L. Yang (see below)

Diagnosis:— Differing from other genera of Boletoideae by the coniodermal pileipellis.

Description:— Basidiomata small, stipitate-pileate with tubular hymenophore. Pileus plano-convex and rugulose when mature. Tubes adnexed to emarginate, relatively narrow, yellowish, with roundish to angular pores concolorous with inner sides. Stipe central, striate, concolorous with the pileus. Context whitish, without a colour change after touch or damaged.

Basidiospores more or less fusiform and inequilateral in side view with slight suprahilar depression, nearly oblong in ventral view, smooth. Basidia clavate, two- to four-spored, thin-walled, nearly colourless. Tube trama more or less divergent, slightly gelatinized. Cheilocystidia more or less fusiform, nearly colourless. Pleurocystidia more or less fusiform, nearly colourless. Pileipellis composed of a conioderm. Stipitipellis composed of a rectocutis, locally spotted with hymeniform tufts of caulocystidia. Clamp connections absent.

Phylogeny:— According to the BLAST search of nrLSU sequences in GenBank ( NCBI 2025), our collections HKAS147747 and HTBM0884 represent a single species of Boletoideae uncertain in generic level. Therefore, a phylogeny was inferred to classify our collections with representative collections of known genera of Boletoideae and our collections as the ingroup, and one collection of Suillelloideae as the outgroup according to a recent study on phylogeny of Boletales ( Wu et al. 2023) , using four loci (nrLSU, rpb1, rpb2 & tef-1α) necessary for resolving the phylogeny of Boletoideae ( Table 10; Supplement 11). In the result, the ML and BI topologies are almost identical, only with a minimal variation in statistical support, so only the tree inferred from the ML analysis is displayed ( Fig. 18). Our collections form a distinct clade representing an undescribed genus, with relationships to other genera unresolved.

Notes:— This genus currently comprises two species with type locality close to each other. See below for details.

paratypes of a species are only indicated when its holotype is not present.

Floriboletus tianheensis Kun L. Yang, Jia Y. Lin & Zhu L. Yang , sp. nov. ( Figs 18–19; Table 10; Supplements 2 and 11)

Registration identifier FN572711

Etymology:— Referring to the type locality.

Type:— CHINA. Guangdong Province: Guangzhou City, Tianhe District, South China Agricultural University , Arboretum , 23°09’27”N, 113°21’22”E, elevation 40 m, May 22, 2023, Jia Y . Lin & Kun L . Yang, L2352 ( HKAS147747 , holotype ( ITS: PV620888 ; nrLSU: PV616963; rpb2: PV642292; tef-1α: PV642310 ); HTBM0885 , isotype) .

Description:— Basidiomata small; odour indistinct; taste unknown. Pileus 20–35 mm in diameter, plano-convex, rugulose, merino white (#F9F5EC), light apricot orange (#F7D7B2) to sandal brown (#BA8B70). Tubes adnexed to emarginate, relatively narrow, up to 7 mm long; surface light cardamon yellow (#E9E9AD), with roundish to angular pores 1–3 per mm; inner sides concolorous with the surface. Stipe central, 49–62 mm long, 3–5 mm thick, subcylindrical, striate, concolorous with the pileus. Context ceramic white (#FEFEFA), without a colour change after touch or damaged.

Basidiospores {40/2/2} 8–10 [9.10 ± 0.54, 9.00] × 3.5–4 (5) [3.70 ± 0.33, 3.50] µm, Q = (1.80) 2.00–2.86 [2.48 ± 0.24, 2.71], more or less fusiform and inequilateral in side view with slight suprahilar depression, nearly oblong in ventral view, thin-walled, smooth, yellowish to brownish, with a small apiculus. Basidia 17–25 × 7.5–10 μm, clavate, two- to four-spored, thin-walled, nearly colourless. Tube trama more or less divergent, slightly gelatinized, composed of 3–18 µm wide, thin-walled, nearly colourless, compact, moderately branching hyphae. Cheilocystidia rare, 33–42 × 7–9 µm, more or less fusiform, thin-walled, smooth, nearly colourless. Pleurocystidia rare, 28–47 × 7–11 µm, more or less fusiform, thin-walled, smooth, nearly colourless. Pileipellis composed of a slightly gelatinized conioderm by inflated cells sized 9–30 × 8.5–24 µm, subglobose to oblate ellipsoid, thin-walled to slightly thick-walled, yellowish. Stipitipellis composed of a rectocutis, locally spotted with hymeniform tufts of caulocystidia sized 9–27 × 6.5–13 µm, slightly yellowish. Clamp connections absent.

Habit and distribution:— Solitary, on soil, in southern subtropical monsoon forests dominated by plants of Fagaceae and Pinaceae . Currently known from China.

Other collection examined:— CHINA. Guangdong Province: Guangzhou City, Tianhe District, South China Agricultural University , Arboretum , 23°09’27”N, 113°21’22”E, elevation 40 m, May 22, 2023, Jia Y . Lin & Kun L . Yang, L2351 ( HTBM0884 ) .

Phylogeny:— See Floriboletus .

Notes:— This species is similar to the “ Boletus puellaris ” previously described in the same region. See below for details.