Scleroderma venenatum Y.Z. Zhang, C.Y. Sun & Hai J. Li, 2020

Zhang, Yi-Zhe, Sun, Cheng-Ye, Sun, Jian, Zhang, Kai-Ping, Zhang, Hong-Shun, Guo, Xiang, Zhou, Ya-Juan, Zheng, De-Sheng & Li, Hai-Jiao, 2020, Scleroderma venenatum sp. nov., S. venenatum var. macrosporum var. nov. and S. suthepense new to China, Phytotaxa 438 (2), pp. 107-118 : 113-115

Scleroderma venenatum Y.Z. Zhang, C.Y. Sun & Hai J. Li , sp. nov. ( Figs. 3 , 5b and 6c )

MycoBank: MB826961

Diagnosis:—Basidiome sessile, opening through an irregular, lacerate apical pore. Peridium thin, consisting of two layered, brown to greyish brown, surface with scattered, small and thin scales. Presence of moniliform hyphae in gleba and middle size basidiospores, 9–13μm diam, with dense narrow pyramidal warts.

Holotype:— CHINA. Guizhou Province, Qiandongnan Miao and Dong Autonomous Prefecture , Huangping County, Xinzhou Town , Taiweng Village , on ground of Pseudostellaria heterophylla , 31 May 2017, GZ170619-01.

Etymology:— venenatum (Lat.) refers to the poisonous basidiomes.

Basidiome. Basidiome epigeous, globose to subglobose, 0.8–3.5 cm in diam., sessile, rhizomorphs well developed, white to cream, ca. 0.5−1.2 cm height. Peridium 0.4–0.7 mm thick when fresh, leathery, surface with scattered, small and thin scales, brown to greyish brown, consisting of two layers. The outer layer consists of thick-walled, yellowish to yellowish brown hyphae, simple septa, 3–6 µm in diam. ( Fig. 3g ). The inner layer consists of thick-walled, hyaline, branched hyphae with simple septa, absence of clamp connections, 4–10 µm in diam. ( Fig. 3f ). Dehiscence by an irregular, lacerate apical pore. Gleba dark greyish brown, dark grey to back and pulverulent when mature, composed of hyaline hyphae, 3−5 µm in diam. ( Fig. 3e ), with branched and moniliform hyphae ( Fig. 3c ), occasionally swollen up to 8 µm ( Fig. 3d ). Basidia not observed. Basidiospores golden yellowish to yellowish brown in water or KOH, mostly globose, rarely subglobose, IKI−, 9–13 μm in diam. (n = 60/2) including ornamentation ( Figs. 3b , 5b and 6c ), echinulated, covered with dense narrow pyramidal warts, spine 1–2.5 μm in length and 1–2 μm thick at the base.

Additional specimen examined. CHINA. Beijing, Miyun District, Jugezhuang Town, Dongkanggezhuang Village, on angiosperm ground, 01 August 2017, MY20170801-01.

Remarks. Scleroderma venenatum is characterized by its globose to subglobose, sessile basidiome, with white to cream, well developed rhizomorphs, thin, two layered peridium, brown to greyish brown surface with scattered, small and thin scales, presence of moniliform hyphae in gleba and middle size basidiospores with dense narrow pyramidal warts. Scleroderma verrucosum shares thin peridium with small scales on the surface and similar echinulate basidiospores (8–11 μm) with S. venenatum , but can easily differ from the latter species by its brown to pale yellowish peridium surface and well-developed pseudostipe ( Li 2003; Liu 2005; Li et al. 2015).

Scleroderma venenatum var. macrosporum Y.Z. Zhang, C.Y. Sun & Hai J. Li , var. nov. ( Figs. 4 , 5c and 6b ) MycoBank: MB826962

Diagnosis:—Compared with S. venenatum var. venenatum , S. venenatum var. macrosporum has distinctly smaller basidiome, 0.5–1.4 cm in diam., larger basidiospores, 12–16 μm, and clamped connections occasionally present in the inner layer of the peridium.

Holotype:— CHINA. Yunnan Province, Lincang, Qi Mount , alt. 1630 m, 23°54′16″ N, 100°04′26″ E, on ground of Delonix regia , 29 August 2015, Li 150829-04.

Etymology. macrosporum (Lat.) refers to the lager basidiospores compared to S. venenatum .

Basidiome. Basidiome epigeous, globose to subglobose, 0.5–1.4 cm in diam., sessile, rhizomorphs well developed, white to cream, ca. 0.5–0.8 cm length. Peridium 0.2–0.3 mm thick when fresh, leathery, surface with scattered, small and thin scales, brown to greyish brown, consisting of two layers. The outer layer consists of thick-walled to subsolid, yellowish to golden hyphae, simple septa, 3–7 µm in diam ( Fig. 4f ). The inner layer consists of thick-walled, hyaline, frequently branched hyphae mostly with simple septa and rarely with clamp connections, 3–6 µm in diam. and occasionally swollen up to 10 µm ( Fig. 4e ). Dehiscence by an irregular, lacerate apical pore. Gleba ash grey, grey to dark grey and pulverulent when mature, composed of hyaline, thin- to slightly thick-walled and frequently branched hyphae with simple septa, 3.5–6 µm in diam. ( Fig. 4c ), branched and moniliform hyphae also present ( Fig. 4d ). Basidia not observed. Basidiospores golden yellowish to yellowish brown in water or KOH, mostly globose, rarely subglobose, IKI−, 12–16 (–17) μm in diam. (n = 90/3) including ornamentation ( Figs. 4b , 5c and 6b ), echinulated, covered with dense narrow pyramidal warts, spine 1–3 μm in length and 1–2.5 μm thick at the base.

Additional specimens examined. CHINA. Yunnan Province, Honghe, Mile County, Miyang Town, Weihu Village, Sanqidi Mountain, alt. 1790m, 24°23′17″ N, 103°32′47″ E,on angiosperm ground, 08August 2016, MLMY20160808009 & MLMY20160808016.

Remarks. Morphologically, Scleroderma venenatum var. macrosporum is similar to S. venenatum var. venenatum , but the former species has small basidiome (0.5–1.4 cm in diam.), distinctly larger basidiospores (12–16 μm VS 9–13 μm), and clamp connections occasionally present in the inner layer of the peridium. Based on the surface characteristics of basidiospores, S. venenatum belongs to Scleroderma sect. Scleroderma ( Guzmán et al. 2013) . No clamp connections were observed in S. venenatum var. venenatum and most parts of S. venenatum var. macrosporum . It was interesting that few clamp connections were discovered in the inner layer of the peridium from the latter species. Scleroderma areolatum also has sessle basidiome, similar echinulated basidiospores (11–17 μm) with dense narrow pyramidal warts up to 2.8 μm in length, its’ larger basidiome (1–4 cm length), brownish violet to dark olivaceous with abundant yellowish trama veins gleba can easily differentiate from S. venenatum var. venenatum ( Liu 2005) .

Figures

FIGURE 3. Scleroderma venenatum (from the holotype). a. Basidiomata. b. Basidiospores. c. Moniliform hyphae from gleba. d. Swollen hyphae from gleba. e. Hyphae from gleba with simple septa. f. Hyphae from inner peridial layer. g. Hyphae from outer peridial layer. (scale bars: a = 1 cm, b–g = 10 μm).

FIGURE 4. Scleroderma venenatum var. macrosporum (from the holotype). a. Basidiomata. b. Basidiospores. c. Hyphae from gleba with simple septa. d. Moniliform hyphae from gleba. e. Hyphae from inner peridial layer mostly with simple septa and rarely with clamp connections. f. Hyphae from outer peridial layer. (scale bar: a = 1 cm, b–e = 10 μm).

FIGURE 5. Basidiospores of Scleroderma spp. (drawn by Hai-Jiao Li). a. Basidiospores of Scleroderma suthepense. b. Basidiospores of S. venenatum var. venenatum (drawn from the holotype). c. Basidiospores of S. venenatum var. macrosporum drawn from the holotype). (scale bar = 10 μm)

FIGURE 6. SEM photos of Scleroderma basidiospores. a. Basidiospores of Scleroderma suthepense. b. Basidiospores of S. venenatum var. macrosporum (from the holotype). c. Basidiospores of S. venenatum var. venenatum (from the holotype, scale bar = 5 μm).