AT A GLANCE
- Common Name: Plums and Custard
- Scientific Name: Tricholomopsis rutilans
- Category: Fungi
- Subcategory: Mushrooms
- Range: Circumboreal across temperate and boreal forests of Europe, North America, northern Asia, and introduced to parts of the Southern Hemisphere
- Habitat Type: Coniferous and mixed woodlands, fruiting directly on decaying pine, spruce, and fir logs, dead conifer stumps, and buried woody roots
- IUCN Red List Status: Least Concern
- Lifespan: Fruiting body lasts 7 to 14 days; underground/wood-decay mycelium lives for years
- Diet: Saprobic (lignicolous wood-decay fungus breaking down dead conifer timber, causing white rot)
- Average Size/Weight: Cap diameter 4 to 12 cm; stipe 5 to 10 cm tall, 1 to 2.5 cm thick
- Key Defining Feature: Stunning woodland mushroom with a vibrant canary-yellow cap and gills densely sprinkled with velvety plum-purple to wine-red fibrillose scales
Overview
Plums and Custard (Tricholomopsis rutilans) is one of the most delightfully named and visually striking woodland fungi in the Northern Hemisphere. Belonging to the family Tricholomataceae, this wood-decaying basidiomycete produces vibrant, fleshy fruiting bodies whose color scheme perfectly evokes a traditional English dessert: bright egg-custard-yellow gills and background flesh lavishly dusted with a velvety carpet of deep plum-purple or wine-red scales. Fruiting from late summer through late autumn on decaying conifer wood, it brings a burst of cheerful color to the forest floor.
Biology and Physical Characteristics
The pileus (cap) of Tricholomopsis rutilans begins convex or bell-shaped before expanding to become broadly convex or nearly flat, often with a slight central umbo, reaching 4 to 12 cm across. The surface has a warm egg-yellow ground color, but is densely blanketed in tiny, velvety, felt-like scales (fibrils) of rich purplish-red, crimson, or plum-violet that are concentrated most heavily at the center. The gills (lamellae) are crowded, adnexed to sinuate, and a radiant, luminous canary-yellow, producing white basidiospores. The stipe is cylindrical, yellow, and adorned with wine-red scales similar to the cap, lacking a ring.
Behavior and Ecology
Tricholomopsis rutilans is an obligate saprotroph, decomposing dead conifer timber, especially Scots pine (Pinus sylvestris), Norway spruce (Picea abies), and Douglas fir (Pseudotsuga menziesii). Its subterranean mycelium secretes lignin-degrading enzymes that break down tough structural wood fibers, producing a soft white rot and recycling vital nutrients back into the woodland ecosystem. It typically fruits in small clusters or pairs directly out of moss-covered pine stumps and rotting logs after heavy autumn rains. While technically non-toxic, it is considered inedible due to an unpleasant sour or woody taste and bitter aftertaste.
Conservation and Human Impact
Plums and Custard is classified as Least Concern on global and European fungal red lists. It is widespread, frequent, and stable throughout the coniferous and mixed forest zones of the Holarctic. It readily thrives in commercial pine plantations and managed timber forests as well as old-growth wilderness areas, benefiting directly from modern sustainable forestry practices that retain dead stumps and coarse woody debris on site.
Interesting Factoid
This mushroom gets whimsical common name ‘Plums and Custard’ from its remarkable colors: the velvety plum-purple scales dusted over an intense canary-yellow cap and gills look exactly like stewed plums poured over creamy vanilla custard.