Sheathed woodtuft (Pholiota mutabilis, Kuehneromyces mutabilis)

A basidiomycete mushroom forming dense clusters on dead wood, especially on decaying trunks and stumps of broadleaf trees in temperate and humid forest environments. Fruiting bodies show a yellow-honey to ochre cap, lighter toward the margin, with a surface that may be smooth or slightly scaly. The stem is slender, fibrous, and usually paler than the cap, displaying a distinct ring zone as a remnant of the partial veil. Growth occurs mainly from spring to autumn during wet periods, with abundance strongly influenced by substrate availability and microclimate.

Morphologically, the caps are convex in early development and gradually flatten with age. The gills are dense, attached to the stem, and evolve from pale yellowish to brownish-ochre tones as the mushroom matures. The clustered habit, sometimes forming very compact groups, is a distinctive feature of the species and contributes to its characteristic appearance on fallen logs and decorticated wood.

The composition of Pholiota mutabilis is dominated by water, fibre, proteins, nitrogenous compounds, and smaller proportions of carbohydrates. The fruiting body also contains traces of minerals (notably potassium and phosphorus) and minor secondary metabolites typical of wild macrofungi. Quantitative variations depend on substrate type, developmental stage, humidity, and temperature conditions during growth.

From a practical standpoint, the sheathed woodtuft requires particular caution due to its resemblance to toxic species with similar morphology. Any possible edible use must therefore rely on certain identification by trained mycologists, avoiding collection based solely on general appearance. In food or processing contexts, evaluation focuses on the integrity of specimens, absence of contamination, and accurate species confirmation, as these factors are essential to determine suitability and ensure safe handling of the fungal material.

Studies

In the genus Pholiota, there are iron, manganese and, above all, selenium (1), and beta-carotene is also present.

This mushroom, as well as Kuehneromyces mutabilis, Lactarius quietus, and Lentinellus cochleatus, has shown antitumor activity with potential inhibitory effects on cell growth (3).

References__________________________________________________________________________

(1) Gąsecka, M., Mleczek, M., Siwulski, M., Niedzielski, P., & Kozak, L. (2015). The effect of selenium on phenolics and flavonoids in selected edible white rot fungi. LWT-Food Science and Technology, 63(1), 726-731.

Abstract. The objective of the study was to determine total phenolic and flavonoid content and composition as well as antioxidant activity in Pholiota nameko, Pleurotus eryngii and Pleurotus ostreatus growing on substrates supplemented with selenium salts. The concentration of Se in control samples (without Se addition) was 4.86 ± 0.12 mg/kg for P. nameko, 2.54 ± 0.22 mg/kg DW for P. ostreatus, and 7.34 ± 0.17 mg/kg DW for P. eryngii. The addition of selenium salts to the substrate resulted in increases of Se concentration in the fruiting bodies. Total phenolic and flavonoid concentration was the highest for P. nameko. In all examined mushrooms p-hydroxybenzoic, p-coumaric and ferulic acids and myricetin were identified, while gallic and t-cinnamic acids were identified only in P. nameko. The greatest inhibition of DPPH and ABTS radicals was confirmed for P. nameko, and the lowest for P. eryngii. Se supplementation at the concentration between 0.5 and 5.0 mmol/L inhibited growth of fruiting bodies of the mushrooms and enhanced the biosynthesis of phenolics and flavonoids. The increase of scavenging activity for all mushrooms was confirmed in Se-treated mushrooms. The inhibition of DPPH and ABTS radicals was correlated with total phenolic and flavonoid contents only for P. ostreatus.

(3) Vanyolos A, Kovacs B, Bozsity N, Zupko I, Hohmann J. Antiproliferative Activity of Some Higher Mushrooms from Hungary against Human Cancer Cell Lines.- Int J Med Mushrooms. 2015

Abstract. In the present work, aqueous and organic extracts of 16 Basidiomycetes mushrooms and 1 Ascomycetes mushroom were investigated in vitro for their antiproliferative activity against HeLa (cervix epithelial adenocarcinoma), A431 (skin epidermoid carcinoma), A2780 (ovarian carcinoma), and MCF7 (breast epithelial adenocarcinoma) cells, using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay. A total of 68 n-hexane, chloroform, 50% methanol, and water extracts of selected species were screened for their potential cell growth inhibitory activity. Our experiments revealed that 7 of 17 species demonstrated notable antiproliferative activity (at least 50% inhibition of cell proliferation) against one or more cell lines. Kuehneromyces mutabilis, Lactarius quietus, and Lentinellus cochleatus, which exerted the highest activity on cancer cells, are considered valuable species in the perspective of further mycochemical studies.