Spongispora temasekensis G. Wu, S.M.L. Lee, E. Horak & Zhu L. Yang, in Wu et al. Mycologia 110(5): 922 (2018)
Etymology: temasekensis (Latin), pertaining to Temasek, the old Malayan name of Singapore used in the 13th and 14th centuries
Pileus 30–70 mm diam, convex, becoming broadly plano-convex with age; chocolate brown to brown (6E4– 6F4), brownish (7D4–7D5), brownish orange (7C4–7C5); surface dry, subtomentose when young, cracking into patches with age; context 6–8 mm thick, whitish, very slowly staining pale brown on exposure. Tubes adnexed, up to 1.5 cm long, concolorous with pores when young, becoming blond (4C4) and yellowish brown to light brown (5D4–5D5) with age. Pores 0.5–2/mm wide, roundish to irregularly angular, at first whitish to cream (2A2), becoming apricot yellow to grayish orange (5B5– 5B6) with age, turning brownish to brown after bruising. Stipe 45–70 × 8–10 mm, central, subcylindrical, attenuated upwards; yellowish white (1A2) at the apex, orange gray (5B2–6B2), brownish gray (5D3–5D4), brownish orange to brownish (7C3–7D3) in the lower part; surface wholly covered with brownish to blackish brown reticulations, sometimes coarse; context whitish to cream in the upper part, staining pale brown very slowly on exposure; pale yellow in the lower part, slowly staining ochraceous orange then becoming brownish on exposure, especially at the base. Basal mycelium cream to pale yellow above ground, light azure blue under leaf litter–soil substrate.
Basidiospores (13–)13.5–16(–16.5) × (9–)10–12(–13) μm [Q = (1.18–)1.22–1.45(–1.5), Qm = 1.34 ± 0.08] with ornamentations 3–4 μm high, broadly elliptical to ovoid and inequilateral in side view with indistinct suprahilar depression, elliptical to ovoid in face view, yellowish to brownish yellow; surface irregularly warty under light microscopy, rugulose around the apiculus but spongelike with irregular clefts, cracks, and warts elsewhere under SEM; brown in deposit. Basidia 25–35 × 13–18 μm, broadly clavate, 4-spored. Hymenophoral trama boletoid with hyphae diverging from the central strand to the subhymenium, gelatinous; hyphae subcylindrical to cylindrical, 4–11 μm wide. Cheilocystidia 31–62 × 8–15 μm, scattered, usually fusoid-ventricose with short beak, occasionally lageniform to obclavate, thin-walled, usually containing yellow to brownish yellow intracellular pigments. Pleurocystidia 57–89 × 12–26 μm, scattered, fusoid-ventricose to broadly fusoid-ventricose, usually with short beak, thin-walled. Pileipellis an interwoven trichodermium, up to 200 μm thick, composed of broad filamentous hyphae 8–11 μm wide, containing yellowish brown to brown intracellular pigments, with subcylindrical terminal cells 19–58 × 7–12.5 μm, slightly thick-walled (ca. 1 μm). Pileal trama composed of interwoven hyphae 6–14 μm wide. Stipitipellis ca. 130 μm thick, and nearly 700 μm thick at the reticulations, hymeniform; caulocystidia 16–82 × 9–22 μm, rare, vase-like with long beak, rarely fusoid-ventricose. Stipe trama composed of parallel hyphae 4–9 μm wide, thin-walled. Clamp connections absent.
Ecology, habitat, and distribution: On soil in leaf litter around Hopea odorata (Dipterocarpaceae), Singapore, Mar and Nov.
Index Fungorum number: IF823812
Figure 1. ML tree of the Leccinoideae inferred from 28S, TEF1, RPB1, and RPB2 nucleotide sequences. Bootstrap values (BS) ≥50% and PPs ≥0.90 are shown on supported branches. The target species, Spongispora temasekensis, is labeled in bold within a grayish box.
Figure 2. Fresh basidiomes of Spongispora temasekensis and its putative ectomycorrhizal host. A–B. Hopea odorata (Dipterocarpaceae), putative ECM plant associate with Spongispora temasekensis. C–I. Fresh basidiomes of Spongispora temasekensis. C, D, F–H. Ho 14-551, holotype. E, I. SL962. Arrows point to the blue mycelium at the stipe base.