Top view of "plums and custard", Tricholomopsis rutilans (Schaeff.) Singer, displaying the characteristic red squamules.
Photo credit: Alan Rockefeller
Source: Mushroom Observer (CC-by-sa-3.0)
Agaricus rutilans Schaeff.
Fung. Bavar. Palat. 4: 51 (1774)
Agaricus serratis Bolton
Hist. fung. Halifax (Huddersfield) 1: pl. 14 (1788)
Agaricus variegatus Scop.
Fl. carniol., Edn 2 (Wien) 2: 434 (1772)
Agaricus xerampelinus Sowerby
Coloured figures of English Fungi or Mushrooms (London) 1: tab. 31 (1796)
Gymnopus rutilans (Schaeff.) Gray
Nat. Arr. Brit. Pl. (London) 1: 605 (1821)
Tricholoma rutilans (Schaeff.) P. Kumm.
Führ. Pilzk. (Zwickau): 133 (1871)
Tricholoma variegatum (Scop.) Fr.
Syll. fung. (Abellini) 5: 96 (1887)
Tricholomopsis rutilans var. variegata (Scop.) Bon
Encyclop. Mycol. 36: 291 (1984)
Tricholomopsis variegata (Scop.) Singer
Annls mycol. 41(1/3): 67 (1943)
Plums and custard
Tricholome rutilant (French)
Rötlicher Holzritterling Purpurfilziger (German)
Purpur væbnerhat (Danish)
Рядовка жёлто-красная Опёнок жёлто-красный (Russian)
Šafránka červenožlutá (Czech)
Rycerzyk czerwonozłoty (Polish)
Čírovec červenožltý (Slovakian)
Rdečkasta trhlenka (Slovenian)
Tricoloma rutilante (Spanish)
Bársonyos pereszke (Hungarian)
Rød stubbemusserong (Norwegian)
Cap: 3-8 cm in diameter, obtuse with an incurved often ribbed margin, expanding to campanulate and nearly flat in maturity, usually retaining a low obtuse umbo; surface dry and tomentose-squamulose, the squamules bright purplish red, at times appearing to be covered by a closely matted purplish-red tomentum and more granular-roughened than scaly; scales developing in age as the tomentose layer becomes pulled apart; a strong yellow cast finally showing beneath the fibrillose layer, or this region often yellowish where bruised; flesh thick, up to 2 cm in the umbo, about 5 mm half way to the margin, pale yellow, the odor none, the taste slightly of radish.
Gills: adnate becoming adnexed, narrow (5 mm), crowded (3-4 tiers of lamellulae), straw yellow or a deeper shade, edges crenulate.
Note the characteristic red fibrils on the stem with a pale zone at the apex, and the yellow gills.
Photo credit & source: Alan Rockefeller, as above.
Stem: 5-10 cm long x 8-15 mm diameter at apex (up to 25 mm at the slightly enlarged base) stuffed becoming hollow, yellowish within, the surface covered with appressed "Corinthian red" fibrils with a paler zone at apex, staining yellow where handled.
Spore print: white.
Spores: ellipsoid to drop-shaped, smooth, nonamyloid, 5-6 x 3.5-4.5 um.
Odor: farinaceous. An in-depth analysis of the various volatile and semivolatile compounds responsible for the aroma of this species is presented in De Pinho et al., (2008).
Edibility: edible, or inedible depending on your taste and who you listen to. Not recommended by several authors.
Habitat: found fruiting solitry or clustered on conifer stumps, logs, and wood chips.
Distribution: T. rutilans has a widespread distribution, especially in Northern temperate regions.
Description largely adapted from Smith (1960), who also gives details on microscopic features, and mentions the variant T. rutilans var. albofimbriata, characterized by elongated cheilocystidia.
Amino acid composition
Various unusual amino acids have been isolated and identified from T. rutilans, namely l-3-(3-carboxy-4-furyl)alanine (Hatanaka and Niimura, 1975), l-2-aminohex-4-ynoic acid (Hatanaka et al., 1972) and 2-amino-3-hydroxyhex-4-ynoic acid as a mixture of threo- and erythro-2-amino-3-hydroxyhex-4-ynoic acid forms (Niimura and Hatanaka, 1974). An extensive compositional amino acid analysis was recently undertaken, and this species had the lowest total amino acid composition (>5 g/kg dry matter) of all eight edible species tested; glutamine (1.46 mg/kg) and alanine (0.94 mg/mg) were present in the greatest abundance (Ribeiro et al., 2008).
Organic acids & phenolics
The sum of the carboxylic acids assayed in T. rutilans (specifically: oxalic, aconitric, citric, ketoglutaric, malic and quinic, ascorbic, succinic, shikimic and fumaric acids) was approximately 40 g/kg dried mushroom. This species contains malic and quinic acids as the major compounds (approximately 52% of nonaromatic acids), followed by citric acid (19% of nonaromatic compounds). Variations in geographical location and maturity of the collected specimens resulted in some variability in results (Ribeiro et al., 2006).
The highly oxygenated phenol fomecin B (shown below) has been isolated from T. rutilans. Fomecin B is cytotoxic against HeLa, MDCK, and FL cells with IC50 values of 20, 14, and 17 μg/mL, respectively (Liberra et al., 1995).
The novel sterols 3β,5α-dihydroxy-(22E,24R)-ergosta-7,22-dien-6β-yl oleate and 3β,5α-dihydroxy-(22E,24R)-ergosta-22-en-7-one-6β-yl oleate has been isolated from the ethanol extract, as well as the previously known (22E,24R)-5α,8α-epidioxyergosta-6,22-dien-3β-ol, 3β-hydroxy-(22E,24R)-ergosta-5,8,22-trien-7-one, and (22E,24R)-5α,6α-epoxyergosta-8(14),22-dien-3β,7α-diol (Wang and Lui, 2004).
Measured with the DPPH• radical scavenging assay, the antioxidative capacity of T. rutilans although relatively low, was the highest of several edible mushroom species tested (Ribeiro et al., 2006). The extract showed a concentration-dependent DPPH• radical scavenging ability; at a concentration of 600 μg/ml, radical scavenging was over 90%.
Polysaccharides extracted from the mycelial culture of T. rutilans and administered intraperitoneally into white mice at a dosage of 300 mg/kg inhibited the growth of both Sarcoma 180 and Ehrlich solid cancers by 60% (Ohtsuka et al., 1973).
T. rutilans has been studied for its influence on the binding of lipopolysaccharides to CD14+ cells and on the release of inflammatory mediators (Koch et al., 1998, 2002). Ethanol extracts were shown to reduce the binding of LPS and the release of mediators, as well as decrease the LPS-induced release of IL-1 and TNF-αin a concentration dependent manner.
De Pinho PG, Ribeiro B, Goncalves RF, Baptista P, Valentao P, Seabra RM, Andrade PB.
Correlation between the pattern volatiles and the overall aroma of wild edible mushrooms.
J Agric Food Chem 2008 56(5):1704-12.
Hatanaka S-I, Niimura Y.
l-3-(3-carboxy-4-furyl)alanine from Tricholomopsis rutilans.
Hatanaka SI, Niimura Y, Taniguchi K.
l-2-Aminohex-4-ynoic acid: a new amino acid from Tricholomopsis rutilans.
Phytochemistry 1972 11(11):3327-9.
Koch J, Witt S, Liberra K, Lindequist U.
The influence of extracts of Tricholomopsis rutilans (schff.ex fr.) sing. on the binding of LPS to CD14+- cells and on the release of inflammatory mediators.
Phytother. Res. 1998 12:27-29.
Koch J, Witt S, Lindequist U.
The influence of selected higher Basidiomycetes on the binding of lipopolysaccharide to CD14+ cells and on the release of cytokines.
Int J Medicin Mushr. 2002 4(3):229-235.
Liberra K, Jansen R, Wegner U, Lindequist U.
Tricholomopsis rutilans Formecin B as a cytotoxic metabolite from the basidiomycete (Schaeff. ex Fr.) Sing.
Pharmazie 1995 50(5):370-371.
Niimura Y, Hatanaka SI.
l-threo- and l-erythro-2-amino-3-hydroxyhex-4-ynoic acids: new amino acids from Tricholomopsis rutilans.
Phytochemistry 1974 13:175-178.
Ohtsuka S, Ueno S, Yoshikumi C, Hirose F, Ohmura Y, Wada T, Fujii T, Takahashi E.
Polysaccharides having an anticarcinogenic effect and a method of producing them from species of Basidiomycetes.
UK Patent 1331513, 26 September 1973.
Ribeiro B, Rangel J, Valentao P, Baptista P, Seabra RM, Andrade PB.
Contents of carboxylic acids and two phenolics and antioxidant activity of dried Portuguese wild edible mushrooms.
J Agric Food Chem. 2006 54(22):8530-7.
Ribeiro B, Andrade PB, Silva BM, Baptista P, Seabra RM, Valentao P.
Comparative study on free amino acid composition of wild edible mushroom species.
J Agric Food Chem 56(22):10973-9.
Tricholomopsis (Agaricales) in the Western Hemisphere.
Brittonia 1960 12(1):41-70.
Wang F, Liu JK.
Two new steryl esters from the basidiomycete Tricholomopsis rutilans.
Steroids 2005 70(2):127-130.
Last modified: 15-Jan-2009