Sanguinoderma bambusae K. Y. Niu, S. M. Tang & Z. L. Luo sp. nov.

Figs 3, 5 c, d

Diagnosis.

Sanguinoderma bambusae differs from S. laceratum by having a dark gray and glabrous pileus, relatively small pores, dissepiments that remain intact when dry, centrally stipitate, slightly curved, grayish-orange to black stipe.

Etymology.

The epithet “ bambusae ” refers to its growth on the ground in bamboo forests.

Holotype.

China • Yunnan Province, Dehong Prefecture, Dendrocalamus spp. forest humus, alt. 1,593 m, 24.754404 ° N, 98.235173 ° E, Kai-Yang Niu, 6 July 2023, HKAS 144474.

Description.

Basidiomata annual, centrally stipitate, coriaceous to corky. Pileus umbelliform, up to 13.5 cm in diameter and 6 mm thick; pileus surface dark gray (# 575757) to black (# 000000), dull, glabrous, slightly dense, and radial fine wrinkles; margin dark gray (# 5 d 5 d 5 d), obtuse, entire, with sparse lacerated-like petal structures, slightly wavy and incurved when dry; Context up to 2 mm thick, homogeneous, slightly orange (# c 2 a 37 f), soft, and corky without black melanoid lines. Tubes up to 4 mm long, with the same color as the context, hard, and unstratified. Pores 6–9 per mm, oval to circular, grayish orange (# 756961) when fresh, becoming red when bruised and then quickly darkening; without discoloration, dissepiments remain intact when dry. Stipe up to 27 cm long, 8 mm in diameter, central, cylindrical, hollow, slightly curved, grayish orange (# 6 b 6252) to black (# 000000), and fibrous to woody.

Hyphal system trimitic with generative hyphae 3–6 μm in diameter, hyaline, thin-walled, and with clamp connections; skeletal hyphae 4–8 μm in diameter, pale yellow, thick-walled with a wide or narrow lumen to subsolid; binding hyphae 1–4 μm in diameter, pale yellow, flexuous, branched. All hyphae IKI – and CB +. Context darkened in KOH. Pileipellis trichoderm is a regular palisade, apical cells 5–7 × 20–32 μm, short clavate, and yellowish brown. Basidiospores broadly ellipsoid, light grey, IKI – and CB + with double and thin walls; exospore wall is smooth; endospore wall features conspicuous pillars, (10.1 –) 10.3–13.8 (– 14.4) × (8.6 –) 8.7–10.9 (– 11.6), L = 11.6 μm, W = 9.6 μm, Q = 1.21 (n = 40 / 2). Under SEM, exospore wall has regular and continuous reticulate protrusions. Cystidia narrowly cylindrical to narrowly clavate, hyaline, thin-walled, and 44–50 × 5–9 μm. Basidia barrel-shaped to widely clavate, hyaline, thin-walled, and 25–26 × 16–18 μm. Basidioles elongated ellipse to ellipse, hyaline, thin-walled, and 20–22 × 14–18 μm.

Additional specimens examined.

China • Yunnan Province, Dehong Prefecture, on Dendrocalamus spp. forest humus, alt. 1,702 m, 24.731679 ° N, 98.255132 ° E, Kai-Yang Niu, 6 July 2023, HKAS 144473.

Notes.

In multi-locus phylogenetic analysis, Sanguinoderma bambusae formed a sister clade with S. ovisporum K. Y. Niu, J. He & Z. L. Luo, and S. laceratum Y. F. Sun & B. K. Cui — all three species have been reported in Yunnan, China. Morphologically, Sanguinoderma bambusae differs from S. ovisporum (Niu et al. 2024) and S. laceratum (Sun et al. 2020) by its centrally stipitate, dark gray pileus and smaller pores (6–9 per mm) (Table 2).

Sanguinoderma dehongense K. Y. Niu, J. He & Z. L. Luo is morphologically similar to S. bambusae with an orange context and tubes, soft and corky without black melanoid lines, stipe length (21 cm), and slightly curved. However, S. dehongense differs by its larger pores (3–4 per mm), smaller basidia (8–11 × 9–13 μm), and basidiospores (9.3–10.8 × 8.4–9.8 μm) (Niu et al. 2024) (Table 2).