Boletales » Sclerodermataceae » Scleroderma

Scleroderma vinaceum

Scleroderma vinaceum Z.W. Ge, R. Wu & L.-R. Zhou

MycoBank Number: MB 847689

Basidiomata are epigeous, 10–20 mm in diam., 15–42 mm in height; upper part is subglobose to oblate. Peridium is leathery, thin, 1–2.5 mm thick, intact in the early stage, splitting up at the apex, and forming an irregular apical pore at maturity. Surface is earthy brown (5E4) to dark brown (5F5), cracking into tiny squamules, exposing the whitish to light yellow (5A2) background, which turns vinaceous after damage. Gleba are light gray (7E1) and compact when young, dark gray –green (2E4) and loose powdery when mature. Stipe is well-developed, cylindrical, firm, light gray, 4–10 mm in length and 3–5 mm in diam.; base with numerous white to whitish rhizomorphs. Basidiospores [100/9/6] (6.0–) 7.0–10.0 (–10.5) µm in diam., 8.0 µm on average, globose, echinulate, gray–brown (4F6) in KOH; covered with dense spines or anemone shaped warts under LM and SEM and spines 1.0–3.0 µm high. Hyphae of the surface are inflated, yellow, and 2.0–3.0 µm in diam.; hyphae from the peridium toward the gleba are septate, colorless, and inflated, at 4.0–6.0 µm in diam. Clamp connections are absent.

Habit and Habitat: Solitary; scattered to gregarious on soil under leaves and the litter of broad-leaved forest dominated by species in Fagaceae.

Additional specimens examined: CHINA. Yunnan Province: Nujiang Lisu Autonomous Prefecture, Lushui City, 6 August 2010, T. Guo 63 (KUN-HKAS 69055, paratype), alt. 2825, in natural forest dominated by species within Fagaceae; Nujiang Lisu Autonomous Prefecture, Fugong County, 5 August 2011, J. Qin 197 (KUN-HKAS 73183, paratype), alt. 2400 m, in natural forest dominated by species within Fagaceae; Nujiang Lisu Autonomous Prefecture, Lushui City, Luzhang Township, 5 August 2011, X. T. Zhu 387 (KUN-HKAS 73764, paratype), alt. 2400 m, in natural forest dominated by species within Fagaceae; Chuxiong Yi Autonomous Prefecture, Chuxiong city, Zixi Mountain, 18 September 2010, Z. W. Ge 2789 (KUN-HKAS 61712, paratype), alt. 2400 m, in natural forest dominated by species within Fagaceae; Chuxiong Yi Autonomous Prefecture, Lufeng city, Wutai Mountain, 12 August 2021, Z. W. Ge 5651 (KUN-HKAS 126617, paratype), alt. 2320 m, in natural forest dominated by species within Fagaceae.

Notes: Scleroderma vinaceum is characterized by small basidiomata with a long stipe, basidiospores with dense spines or sea-anemone-shaped warts, and the vinaceous color change of peridium when bruised. Scleroderma nastii Raut., a species collected from a Quercus forest in a subtropical region of Nepal, also has small basidiomata and similar sized basidiospores; it is close to S. vinaceum according to the ITS phylogeny. However, S. vinaceum has larger basidiomata and basidiospores with spiny ornamentation under LM, and the spines under SEM are irregular, while the basidiospores of S. nastii are irregularly reticulate under SEM. Scleroderma vinaceum is similar to S. verrucosum in the small basidiomata with thin yellowish peridium and echinulate basidiospores. However, S. verrucosum has a shorter stipe, brownish violet to dark olivaceous gleba, and larger basidiospores (9.0–12.0 µm) with shorter spines (0.5–2.0 µm). Scleroderma bermudense Coker, originally described from Bermuda Island, is also similar in size of basidiomata and basidiospores, with a yellow or brownish peridium covered with tightly packed squamules, and changes color to violaceous red when cut. However, S. bermudense has clamp connections and subreticulate basidiospores; old basidiomata with stelliform dehiscence. In addition, the stipe base of S. vinaceum is better developed than that of S. bermudense. Scleroderma venenatum, a widely distributed poisonous species described from China, has similar sized basidiomata. However, S. venenatum is sessile, and has larger basidiospores and clamp connections. In addition, the basidiospores of S. venenatum are golden yellow in KOH under LM, while those of S. vinaceum are vinaceous brown.

Fig. 1 Phylogenetic tree inferred from maximum likelihood (ML) analysis based on the dataset of ITS sequences of Scleroderma species. The ML bootstrap numbers (MLB) ≥ 50% and Bayesian posterior probabilities (BPP) ≥ 0.95 are shown above the branches. New taxa described in the present study are in bold.