Erythrophylloporus cinnabarinus

Erythrophylloporus cinnabarinus Ming Zhang & T.H. Li, in Zhang et al., Mycosystema 37(9): 1119 (2018)

Etymology: cinnabarinus refers to the overall reddish orange (cinnabarine) color of the basidiomes.

Diagnosis: This bolete species can be easily recognized by its orange, reddish orange to yellowish red basidiomata with decurrent lamellate hymenophore, vivid yellow to orange yellow context changing dark violet to blackish blue when exposed.

Pileus 15–55mm in diam., subhemispheric at first, then becoming convex to plane with age, fleshy, dry, deep orange, reddish orange, yellowish red to red (6A7–11A7, 6A8–11A8), in some areas orange (6A8) and with a yellow patches here and there, pruinose to velutinous, faintly squamulose or subfloccose towards the center, glabrous in some areas or faintly pruinose at margin, sometimes cracked, with a thin and incurved margin at first, slightly decurved with age. Context 3–5mm thick in the center, soft, vivid yellow to orange yellow (3A8–4A8), with a thin reddish orange to yellowish red (7A7–8A7) zone beneath the pileipellis and often also above the lamellae, gradually turning dark violet, blackish blue to dark blue (18F4–21F4) when exposed. Lamellae decurrent, thick, 4–6mm broad, crowded, yellowish orange, orange, deep orange, reddish orange to orange red (4A7–8A7), staining grayish blue, grayish turquoise to grayish green (21D5–25D5) when bruised; lamellulae of 3–5 tiers of different lengths, concolorous with lamellae. Stipe 15–35×2–7mm, central, solid, subcylindrical or clavate, equal or slightly tapered downwards, with apex sulcate by the decurrent lamellae, distinctly punctate with orange, reddish orange to orange red (4A7–8A7) scales on a vivid yellow to orange yellow (4A6–8A6, 6A7–8A7) ground, reddish‐orange to yellowish red (6A7–8A7) at apex, reddish yellow, orange to vivid yellow at base; stipe base at times villose, with vivid yellow to deep yellow (2A8–4A8) basal mycelium; stipe context vivid yellow, slightly turning dark violet to blackish‐blue (18F4–21F4) throughout when bruised. Odor indistinct. Taste mild.

Basidiospores 5.5–6.5(–7) × 4.5–5(–5.5)μm, [Q= (1.1–)1.2–1.4(–1.5), Qm=1.28 ± 0.08], broadly ellipsoid, ellipsoid to nearly ovoid, smooth, thin‐walled, yellowish to yellowish brown in 5% KOH, with a large oil drop, inamyloid. Basidia 35–46 × 6–8µm, subcylindrical to clavate, sinuous, usually with yellow contents, 2, 4‐sterigmate, sterigmata up to 4.5µm long. Pleurocystidia 60–95×8–15µm, scattered, conspicuous, projecting straight on lamellar face, fusiform to narrowly fusiform, thin‐walled, smooth, and usually containing yellowish brown pigments slowly dissolving in KOH. Cheilocystidia abundant, similar to pleurocystidia in shape and size, sometimes with dark yellowish brown pigments. Hymenophoral trama subparallel, with hyphae 3.5–6μm wide, pale yellowish to hyaline in 5% KOH. Pipeipellis a subcutis to trichoderm of loosely intermixed, branched hyphae, 5–8μm wide, pale yellowish to hyaline in 5% KOH; terminal cells 22–42×3–7μm, cylindrical, clavate or nearly fusoid. Stipitipellis a tangled layer of repent to suberect hyphae 9–14μm wide, pale yellowish to hyaline in 5% KOH, terminal cells 30–80×7–14μm; with the exception of the basal part, the stipe is covered by a caulohymenium with scattered fertile caulobasidia and caulocystidia, usually fragmented into small caulohymenial elements and forming the dotted ornamentation over the stipe surface. Stipe trama composed of densely longitudinally arranged hyphae, 4–10μm wide, pale yellowish to hyaline in 5% KOH. Clamp connections absent in all parts of basidiome

Habitat, ecology and distribution: Solitary or scattered on the ground with humus and debris in mixed forests dominated by Fagaceae and Theaceae, alt. 500–800m, currently only known from southern China.

Index Fungorum number: IF825539

Figure 1. Maximum likelihood tree illustrating the phylogeny of Erythrophylloporus cinnabarinus and related taxa in Boletaceae, based on ITS sequence dataset. Branches are labeled with maximum likelihood bootstrap higher than 50% and Bayesian posterior probabilities more than 0.9.

Figure 2. Maximum likelihood tree illustrating the phylogeny of Erythrophylloporus cinnabarinus and related taxa in Boletales, based on a multilocus (nrLSU, tef1‐α, rpb1 and rpb2) dataset. Left is the best maximum likelihood (ML) tree from a RAxML search using the GTRGAMMA model, Suillus granulatus (L.) Roussel and S. luteus (L.) Roussel are chosen as outgroups. The putative clade containing Erythrophylloporus cinnabarinus is highlighted in red and shown on the right as an enlargement. Branches are labeled with maximum likelihood bootstrap higher than 50% and Bayesian posterior probabilities more than 0.9.