Tricholomopsis rutilans
Description
Tricholomopsis rutilans is a species of gilled mushroom found across Europe and North America. It has a large stature, reddish-purple cap and contrasting yellow gills. It fruits in conifer woods but is infrequent in some years making finds all the more noteworthy. Despite its inviting appearance, Tricholomopsis rutilans has no redeeming culinary value.
Despite it having yellow gills the spore print is white, proving that gill color alone can not be used to gauge what color the spores will be, if in doubt always perform a spore print.
Tricholomopsis rutilans is edible but not recommended.
Common names: Plums and Custar, Red-haired Agaric.
Mushroom Identification
Ecology
Saprobic on the well-decayed wood of conifers; also occasionally reported in woodchips, sawdust, and lignin-rich soil; growing alone, scattered or gregariously; summer and fall (also in winter and spring in warm climates); widely distributed in North America.
Cap
3–10 cm; convex with an incurved margin, becoming broadly convex, broadly bell-shaped, or nearly flat; dry; densely covered with red to purplish-red or brick red fibrils; with maturity the fibrils aggregating into small scales and the yellowish ground color beneath showing through.
Gills
Attached to the stem; close or crowded; short-gills frequent; yellow.
Stem
3–9 cm long; 1–1.5 cm thick; yellowish, covered with red fibrils like those on the cap—but often more sparsely, especially in age; with a yellow, bald zone at the apex.
Flesh
Yellow to pale yellow.
Odor and Taste
Odor fragrant or not distinctive; taste mild or slightly radishlike.
Chemical Reactions
KOH red on cap surface.
Spore Print
White.
Microscopic Features
Spores 3–5 x 2.5–5 µm; subglobose to broadly ellipsoid; smooth; hyaline in KOH; inamyloid. Lamellar trama subparallel; a bit gelatinized; clamps present. Basidia 4-sterigmate. Pleurocystidia scattered; 30–35 x 5–7 µm; sublageniform to subcylindric; smooth; hyaline in KOH. Cheilocystidia 50–70+ x 20–25 µm; sphaeropedunculate to saccate or swollen-irregular; smooth; thin-walled; hyaline in KOH. Pileipellis a cutis with trichodermial areas; elements 10–20 µm wide, smooth, orangish-walled in KOH; clamps present.
Look-Alikes
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Yellow or yellow-ochre; it is much less common and in Britain it is largely confined to mountain regions of Scotland, only very occasionally turning up on dead pine wood.
Megacollybia fallax
Similar but with a gray-brown cap.
Medicinal Properties
Antioxidant effects
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%.
Antitumor effects
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).
Antiinflammatory effects
T. rutilans has been studied for their 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.
History
Originally described in 1770 by Jacob Christian Schaeffer and called Agaricus rutilans - most gilled fungi were initially placed in a giant Agaricus genus, now redistributed to many other genera - this species was moved into the new genus Tricholoma by Paul Kummer in 1871. There it remained until 1939 when the famous German-born mycologist Rolf Singer assigned it to its present genus Tricholomopsis.
Synonyms of Tricholomopsis rutilans include Agaricus rutilans Schaeff., Agaricus xerampelinus Scop., Gymnopus rutilans (Schaeff.) Gray, Tricholoma rutilans (Schaeff.) P. Kumm., and Tricholoma variegatum (Scop.) Sacc.
The genus Tricholomopsis, established by Rolf Singer in 1939, lies somewhere between the genera Clitocybe and Tricholoma, and the term Tricholomopsis means 'similar to a Tricholoma'. (Tricho- as a prefix refers to hair.)
The specific epithet rutilans means becoming red, as indeed the caps of Plums and Custard usually do.
Photo sources:
Photo 1 - Author: Michel Langeveld (CC BY-SA 4.0)
Photo 2 - Author: User:Strobilomyces (CC BY-SA 2.5)
Photo 3 - Author: Andre Hosper (CC BY-SA 4.0)
Photo 4 - Author: User:Strobilomyces (CC BY-SA 2.5)
Photo 5 - Author: Oleg Kosterin (CC BY-SA 4.0)
