Termitomyces yunnanensis S.M. Tang & Raspé, 2023

Tang, Song-Ming, Vadthanarat, Santhiti, He, Jun, Raghoonundon, Bhavesh, Yu, Feng-Ming, Karunarathna, Samantha C., Li, Shu-Hong & Raspe ́, Olivier, 2023, Morphological and molecular analyses reveal two new species of Termitomyces (Agaricales, Lyophyllaceae) and morphological variability of T. intermedius, MycoKeys 95, pp. 61-82 : 61

Termitomyces yunnanensis S.M. Tang & Raspé sp. nov.

Figs 5 , 6

Etymology.

The epithet “yunnanensis” refers to the holotype coming from Yunnan province.

Type material.

Holotype: China. Yunnan province: Kunming city, Shilin county, 20 August 2020, elev. 1580 m, S.M. Tang (Holotype: HKAS124501, isotype MFLU 22-0144).

Diagnosis.

Differs from other Termitomyces species in having a clearly conspicuously venose pileus surface, and an umbonate perforatorium.

Description.

Basidiomata medium-sized. Pileus 4-8 cm in diam., at first convex becoming convexo-applanate to plano-concave or concave, medium grey (1E1), olive grey (1E2), light grey (1D1) to greenish grey (1D2) at center, light grey (1D1) towards margin, conspicuously venose surface; margin inflexed when young, becoming straight or reflexed when mature; perforatorium an umbo, ca. 7-9 mm, dark grey (1F1); context 2-4 mm thick half-way to the margin, tough, white (1A1). Lamellae subventricose, free to adnexed, crowded; lamellulae in 1-2 tiers, white (1A1), 3-5 mm wide; lamellar edge eroded. Stipe 3-4 × 1-2 cm, central, cylindrical, rarely subbulbous at the base, smooth; context solid, fibrous, white (1A1). Annulus absent. Pseudorhiza terete, tapering downwards, surface grey (1D1-2) to dark grey (1F1-1F2), smooth; context solid, fibrous.. Odour slightly fragrant. Taste not distinctive.

Basidia of two conspicuously different types by the sterigmata apex acute or obtuse, first type rather abundant, sterigmata apex acute, clavate, mostly 2-spored, sometimes 4-spored, 20-30 × 7-15 μm, av. 25 ± 2.4 × 11 ± 1.8 μm, sterigmata 1-4 μm long; the second type fewer in number, sterigmata obtuse, clavate, mostly 2-spored, sometimes 4-spored, 24-32 × 8-15 μm, av. 27 ± 2.2 × 10 ± 1.1 μm, sterigmata 2-3 (-5) μm long. Basidiospores [139/2/2] 6.5-10.2 (-11.1) × (3.9-) 4.5-8.2 (-9.1) μm, Lm × Wm = 8.6 ± 1.0 × 5.9 ± 0.8 μm, Q = 1.2-1.8, Qm = 1.47 ± 0.16, broadly ellipsoid to ellipsoid, colorless, thin-walled, smooth. Hymenophoral trama regular, parallel, 150-200 μm wide, made up of thin-walled, ellipsoid to clavate inflated cells hyphae 20-28 μm wide, filamentous hyphae abundant, 3-6 μm wide. Subhymenium 10-20 μm thick, with 1-2 layers of ovoid, subglobose, fusiform, ellipsoid or irregular cells, 7-13 × 3-6 μm. Cheilocystidia 14-37 × 13-23 μm, av. 23 ± 9.1 × 18 ± 4.9 μm, ellipsoid, obovoid to broadly clavate, thin-walled. Pleurocystidia similar to cheilocystidia in shape, 33-50 × 19-32 μm, av. 37 ± 9.1 × 25 ± 5.8 μm. Lamellar edge heteromorphous, more in number of cheilocystidia. Pileipellis 2-layered, suprapellis an ixocutis, 9-39 × 3-5 μm av. 23 ± 8.1 × 4 ± 0.5 μm, cylindrical hyphae with obtuse apex, thin-walled, hyaline at places in KOH; subpellis made up of inflated elements, subcylindrical, 17-49 × 10-18 μm av. 34 ± 9.2 × 13 ± 2.4 μm. Clamp connections not seen in any tissues.

Habitat and distribution.

Solitary above underground termite nests; basidiomata occurring in summer. Known from southwestern China.

Additional material examined.

China. Yunnan Province: Kunming city, Shilin county, Banqiao town , 11 July 2019 alt. 1500 m, J. He (HKAS 124502); ibid, 11 July 2019, alt. 1350 m, S.M. Tang (KHAS 124503); Yuxi city, Eshan county , 7 August 2019, alt. 1480 m, S.M. Tang (HKAS 124517) .

Notes.

Termitomyces yunnanensis is distinguished from other Termitomyces species by its clearly striated pileus surface, medium grey, olive grey, light grey to greenish grey at center, light grey towards margin on the pileus surface; perforatorium dark grey and umbonate, thin-walled or thick-walled basidia, ellipsoid, obovoid to broadly clavate cheilocystidia and pleurocystidia.

According to our multi-locus phylogenetic analyses, T. yunnanensis was clustered together with T. subumkowaan Mossebo and T. robustus . However, T. subumkowaan has yellowish to brownish grey pileus, obtuse perforatorium concolorous with pileus, stipe cylindrical, bulbous at the base, and pleurocystidia extremely rare ( Mossebo et al. 2002; Mossebo et al. 2017). Termitomyces robustus has bigger pileus (7-11 cm), pileus grey, often rimose-squamulose when dry, perforatorium concolorous with pileus, acute and bigger perforatorium ( Sitotaw et al. 2015).

Morphologically, T. medius R. Heim & Grassé, T. mammiformis , T. griseiumbo and T. striatus are similar to T. yunnanensis in having a clearly striated pileus surface. However, T. medius has smaller pileus (2.2-2.9 cm), and acute perforatorium, reflexed pileus margin when mature, smaller basidiospores (6-8 × 4-4.8 μm) and basidia (17-20 × 7-7.5 μm), pleurocystidia (25-40 × 12-25 μm) narrowly utriform, ovoid to obovoid ( Heim 1977). Termitomyces mammiformis has subconical scales on the pileus surface, and an annulus on the stipe ( Heim 1977). Termitomyces grisumbo has ochraceous pileus, and relatively bigger pileus (12-15 cm), and smaller basidiospores (5.5-7 × 3.5-4.5 μm), pleurocystidia abundant and polymorphic, clavate to pyriform, with one or more transverse septa ( Mossebo et al. 2002).

Termitomyces striatus originally described from Sierra Leone (Africa), has clear striae on the pileus, ring of scales on the pseudorhiza, and small basidiospores (6.5-7.7 × 4-5 μm) ( Heim 1977). However, T. striatus was divided 10 formae ( Mossebo et al. 2009), namely f. Termitomyces striatus annulatus , f. Termitomyces striatus striatus , f. Termitomyces striatus ochraceus , f. Termitomyces striatus bibasidiatus , f. Termitomyces striatus griseus , f. Termitomyces striatus griseiumboides , f. Termitomyces striatus subumbonatus , f. Termitomyces striatus brunneus , f. Termitomyces striatus pileatus and f. Termitomyces striatus subclypeatus . However, according to the phylogenetic analysis of nrLSU and mtSSU sequence in Mossebo et al. (2017), f. Termitomyces striatus striatus (tgf99), f. Termitomyces striatus bibasidiatus (DM280), f. Termitomyces striatus subumbonatus (DM208) and f. Termitomyces striatus subclypeatus (DM151, DM370) were in a different species-level clades, and should therefore be considered as different species. Termitomyces f. bibasidiatus , f. Termitomyces subumbonatus , f. Termitomyces subclypeatus were originally described from Cameroon (Africa) and these species are morphologically different from T. yunnanensis . Termitomyces f. Termitomyces striatus bibasidiatus has relatively long pseudorhiza (20-60 cm), pale, reddish grey to brownish orange yellow pileus, and globose to ovoid pileipellis cells ( Mossebo et al. 2017). An annulus is present in Termitomyces f. subumbonatus ( Mossebo et al. 2002), but absent in T. yunnanensis . Termitomyces f. subclypeatus has whitish orange to pale orange pileus with a greyish yellow to brownish orange perforatorium ( Mossebo et al. 2017).

Key to species of Termitomyces reported from China

To date, 14 Termitomyces species have been reported from China. However, the identification of some species, namely T. aurantiacus , T. eurrhizus , T. entolomoides , T. globulus , T. mammiformis and T. tylerianus , was based on morphology only. Further studies using DNA sequence analyses are required to confirm or inform the presence of those species in China.

1	Basidiomata small, with pileus diam. ≤ 4.5 cm when mature	2
-	Basidiomata medium to large, with pileus diam.> 4.5 cm when mature	5
2	Pileus surface cream to whitish; pileus diam. 2.5-3.0 cm; perforatorium pointed, pseudorhiza long and slender, cheilocystidia and pleurocystidia absent, annulus present	T. tylerianus
-	Pileus surface brownish-gray, dirty white, grayish brown	3
3	Pseudorhiza absent or present; pileus small, diam. 1.2-2.5 cm, dirty-white, soon split at the margin	T. microcarpus
-	Pseudorhiza present, pileus larger	4
4	Pileus 2.0-4.5 cm diam., stipe white to cream, cylindrical, smooth	T. fragilis
-	Pileus 3.5-4.0 cm diam.; stipe pale grey, tapering upwards, floccules	T. entolomoides
5	Pileus white or greyish white	6
-	Pileus ochraceous-orange or yellowish-brown, grey to dark brown or dirty white	7
6	Stipe surface smooth, perforatorium obtuse, gray to brownish gray	T. heimii
-	Stipe surface squamulose, perforatorium mammiform, pale brown to dark brown	T. mammiformis
7	Pileus ochraceous-orange or yellowish-brown	8
-	Pileus grey to dark brown or dirty white	9
8	Perforatorium mucronate, pileus reddish-brown, 5-8 cm diam.; stipe white to whitish, cylindrical	T. aurantiacus
-	Perforatorium non-differentiated, pileus reddish-brown to yellowish-brown, 15-20 cm diam., stipe white, smooth and tapering upwards	T. globulus
9	Annulus present; perforatorium strongly differentiated; stipe cylindrical, pseudorrhiza black and long	T. eurrhizus
-	Annulus absent, pseudorrhiza white to pale yellow	10
10	Stipe cylindrical	11
-	Stipe tapering upwards	12
11	Pileus densely tomentose to tomentose-squamulose, regular greyish white and grey dark rimose-squamulose in dry condition	T. intermedius
-	Pileus surface conspicuously venose, smooth	T. yunnanensis
12	Stipe surface with white to yellowish-brown floccules and tapering upwards, pileus 5-22 cm diam.; perforatorium broadly round or blunt	T. bulborhizus
-	Stipe surface smooth	13
13	Stipe grey, cheilocystidia few, broadly clavate, perforatorium acute, pileus dark grey, greyish white to grey, stipe greyish white to grey on the surface	T. tigrinus
-	Stipe white, cheilocystidia common mostly Y-shaped, perforatorium obtuse, pileus white to cream, stipe white on the surface	T. upsilocystidiatus

Figures

Figure 5. Fresh basidiomata representative of Termitomyces yunnanensis a, b HKAS 124501 c HKAS 124502 d HKAS 124503 e HKAS 124517. Scale bars: 1 cm. Photographs by Song-Ming Tang.

Figure 6. Termitomyces yunnanensis a lamellar edge and cheilocystidia b pleurocystidia c basidia with acute sterigmata apex d basidia with obtuse sterigmata apex e pileipellis f basidiospores. Scale bars: 10 μm (a-d, f); 20 μm (e). Photographs by Song-Ming Tang.