Blue Foot Mushroom (Clitocybe sordida)
Blue Foot Mushroom (Clitocybe sordida)
Blue Foot Mushroom (Clitocybe sordida) is a lilac-violet edible mushroom that fruits in fairy rings across lawns, meadows, compost heaps, and woodland edges throughout temperate regions worldwide. It is closely related to the Blewit and shares its purple coloring, but is smaller and typically found in more open habitats rather than woodland. It is one of the few blewit relatives to have been successfully cultivated on compost substrates in published scientific trials.
Clitocybe sordida (Schumach.) — also known as Lepista sordida (Schumach.) Singer — Clitocybaceae (trad. Tricholomataceae) — Agaricales
What Is the Blue Foot Mushroom (Clitocybe sordida)?
Blue Foot Mushroom (Clitocybe sordida) is a small-to-medium lilac-violet agaric found across temperate zones worldwide, recognized by its hygrophanous (moisture-sensitive) cap that fades from vivid violet when fresh to tan or pinkish-buff when dry, its pleasant floral or fruity scent, and its tendency to fruit in arcing fairy rings. Unlike many mushrooms in the public spotlight, it belongs to the blewit group — a cluster of violet-toned saprotrophic species long beloved by foragers in Europe and increasingly cultivated in Asia.
Blue Foot Mushroom (Clitocybe sordida) is saprotrophic (obtains nutrition by decomposing dead organic material), which is the key ecological fact separating it from obligate ectomycorrhizal species like chanterelles or matsutake. It does not require a living tree partner. That single biological reality makes cultivation possible — and peer-reviewed literature confirms it has been successfully domesticated and fruited on compost-based substrates, with biological efficiency (BE) figures ranging from 35–43% in controlled trials.
Interested in this species? Out-Grow carries a liquid culture.
Blue Foot Mushroom (Clitocybe sordida) Liquid CultureWhat places Blue Foot Mushroom (Clitocybe sordida) in a genuinely unusual category is the convergence of three features rarely combined in a single edible species: it is the fungus responsible for producing 2-azahypoxanthine (AHX), the first molecularly characterized "fairy chemical" shown to induce the greening rings that give fairy-ring fungi their name; it has a documented genome, mitochondrial genome, and proteomics resources that most edible mushrooms lack; and it sits at the center of a nomenclatural transition — still listed as Lepista sordida in much of the chemistry literature while current taxonomic databases increasingly adopt Clitocybe sordida or Collybia sordida.
How Is Blue Foot Mushroom (Clitocybe sordida) Classified?
The taxonomy of Blue Foot Mushroom (Clitocybe sordida) is in active transition, and a species guide that ignores this does readers a disservice. The species has been placed in at least five genera across its nomenclatural history, and the current preferred name genuinely varies depending on which database or literature source you consult.
The basionym is Agaricus sordidus Schumach. (1803) — placed, as most agarics of that era were, in the vast catch-all genus Agaricus. The species was later moved through Tricholoma (T. sordidum), Rhodopaxillus, and eventually to Lepista sordida (Schumach.) Singer, the name under which nearly all peer-reviewed chemistry, cultivation, and genomics work was published and is still published today. The current leading databases diverge: Index Fungorum maintains Lepista sordida; MycoBank carries a separate page for Clitocybe sordida Velen. (MycoBank #278429); iNaturalist and increasingly current field communities have moved to Collybia sordida.
| Rank | Taxon | Note |
|---|---|---|
| Kingdom | Fungi | |
| Phylum | Basidiomycota | |
| Class | Agaricomycetes | |
| Order | Agaricales | |
| Family | Clitocybaceae (trad. Tricholomataceae) | Recent phylogenetic placement |
| Genus | Clitocybe / Lepista / Collybia | Actively debated; see text |
| Species | C. sordida / L. sordida / Collybia sordida | All refer to the same taxon concept |
| Basionym | Agaricus sordidus Schumach. 1803 |
A 2025 phylogenetic study (PMC12112982) recognized Collybia, Lepista, and Clitocybe as separable clades within Clitocybaceae, but public databases and field communities lag behind. A further complication: NatureServe notes that current Species Fungorum expands Collybia sordida to include Lepista tarda, making the synonymy partly taxon-concept dependent rather than purely nomenclatural. For this guide, Out-Grow's product name (Clitocybe sordida) is used as the primary anchor, with Lepista sordida retained wherever it is the name used by the cited scientific literature.
How Do You Identify Blue Foot Mushroom (Clitocybe sordida)?
Blue Foot Mushroom (Clitocybe sordida) is identified by a combination of size, color behavior, habitat, and scent. No single feature is conclusive on its own — the full picture is needed, particularly because several related lilac agarics share overlapping traits.
The most important single field clue is hygrophanous behavior — the cap fades visibly as it dries, losing violet intensity from the center outward. A single colony can show a full gradient from fresh violet-purple at the young margins to washed-out tan at the center. This fading is more pronounced in Blue Foot Mushroom (Clitocybe sordida) than in its larger relative the wood blewit (Lepista nuda / Clitocybe nuda), which retains violet color longer and more uniformly. The scent is reliably pleasant and aromatic rather than mealy (farinaceous) — a useful distinction from many look-alike brownish clitocyboid species whose odor is floury or rancid.
Lookalike Species
Cortinarius spp. (violet webcaps)
Several purple Cortinarius species share the lilac-violet color. Key differences: rusty-brown spore print (not pale pink); cobweb-like cortina veil remnants on the stem when young; typically more robust and in woodland rather than lawns. Some are seriously toxic (e.g. C. orellanus). Always check spore print color before consuming any violet-toned mushroom.
Wood Blewit (Lepista / Clitocybe nuda)
The closest relative and most common confusion. Wood blewit is larger and fleshier, retains violet color more uniformly without fading from center, has a more robust stem, and prefers woodland litter rather than open lawns and compost. Both are edible when cooked.
Collybia violea
A species described in 2025 that had previously been misidentified as C. sordida or C. nuda in Asian material. Cannot be confidently separated from Blue Foot Mushroom by macroscopic features alone. Multilocus DNA is required. Highlights that not every small lilac blewit in recent Asian collections is sordida sensu stricto.
Amethyst Deceiver (Laccaria amethystina)
Vivid amethyst-purple but has widely spaced, thick, waxy gills — very different from the crowded narrow gills of Blue Foot Mushroom (Clitocybe sordida). Grows singly in woodland. Spore print white. Edible.
Clitocybe nebularis (Clouded Funnel)
Not violet but similar overall silhouette and fairy-ring/lawn habitat. Pale gray-buff cap; crowded decurrent gills; strong farinaceous smell. Causes gastrointestinal upset and is best avoided. The floury odor (vs. the floral scent of Blue Foot) is the clearest separator.
Where Does Blue Foot Mushroom (Clitocybe sordida) Grow?
Blue Foot Mushroom (Clitocybe sordida) is a saprotroph — it decomposes dead organic matter rather than forming partnerships with living tree roots. This places it in the same ecological guild as button mushrooms and oysters, and it is one of the reasons it can be cultivated without a tree partner. In the field, it appears wherever dead vegetable debris accumulates: lawns, meadows, roadsides, gardens, compost heaps, mixed woodland litter, and disturbed ground. The growth pattern is typically clustered or in arcing fairy rings, reflecting the radially expanding mycelial colony beneath the surface.
Distribution is effectively cosmopolitan in temperate zones. Documented records span Europe (including a 2023 first record from Algeria), North America, Asia (China, Taiwan, Japan, Korea), Brazil, and African food-resource surveys. The German Red List assessment rates the species as Least Concern. Seasonal fruiting spans late summer through early winter depending on region; British and Irish sources give June–October; North American field practice emphasizes late summer through autumn; outdoor cultivation notes place fruiting in cool late-season conditions.
The fairy-ring association deserves specific mention. Blue Foot Mushroom (Clitocybe sordida) does not merely grow in fairy rings incidentally — it is one of the model species through which the biochemistry of fairy rings was characterized. The greening arc of grass around a fairy ring is caused by the secretion of AHX (2-azahypoxanthine) and related compounds into the surrounding soil, stimulating plant growth. This makes the species ecologically notable beyond its culinary or pharmaceutical dimensions.
Can You Cultivate Blue Foot Mushroom (Clitocybe sordida)?
Yes — with an important qualification. Blue Foot Mushroom (Clitocybe sordida) has been successfully domesticated and fruited in peer-reviewed trials, making it one of the few blewit relatives with documented cultivation protocols. However, the published data show that performance is highly strain-dependent and that compost-based substrates, not simple sterilized grain or sawdust bags, are the appropriate production medium. Older literature described commercialization as difficult; the modern picture is more optimistic but still not plug-and-play.
The two strongest peer-reviewed references are: a 2021 Dazhou study (China) that domesticated wild strain DAAS-E70 to achieve an average biological efficiency (BE) of 41.22%; and Taiwanese domestication work reporting successful indoor fruiting of four wild strains on compost, with BE ranging from 3.4% (LS-11) to 43% (LS-2). The dramatic strain variation — from barely productive to commercially interesting — is the single most important practical lesson from this literature.
What Out-Grow's Blue Foot Mushroom Liquid Culture Is For
Out-Grow's Blue Foot Mushroom (Clitocybe sordida) liquid culture contains living mycelium ready for agar work, grain spawn preparation, or experimental compost-bed inoculation. Because this species is saprotrophic — not ectomycorrhizal — a liquid culture can legitimately be expanded to grain spawn and used to inoculate compost-based production beds, following the protocols documented in peer-reviewed cultivation trials.
The most evidence-supported workflow is: liquid culture → grain spawn (wheat grain performed best in published trials) → pasteurized compost beds with casing layer → fruiting at 12–23°C and 90–98% RH. Peer-reviewed data support cultivability; the full optimization of the LC-to-bed workflow under hobby-scale indoor conditions remains less documented and will vary by strain.
Cultivation Protocol — Evidence-Based Parameters
Spawn Preparation
Expand liquid culture onto grain spawn. Wheat grain performed best in published trials (5.59 mm/day radial growth), followed closely by cow-manure compost grain (5.57 mm/day). Corncob was significantly slower (2.83 mm/day) and is not recommended as primary spawn substrate.
Substrate Preparation
Compost-based beds — not simple sawdust or straw blocks. The Dazhou protocol used corncob compost supplemented with cow manure 40%, calcium carbonate 2%, calcium sulfate 2%, and rice husk 6%, adjusted to 60–65% moisture. Pasteurize rather than fully sterilize.
Spawn Run
Inoculate at 30 g colonized grain per kg compost. Incubate at 22–25°C, 60–65% RH under plastic cover. Optimal mycelial growth temperature from agar data: 25°C, with a working range of 20–30°C. pH 6.0 optimal; pH above 8 significantly reduces performance.
Casing
Once the compost surface is colonized, apply a 2–3 cm casing layer of sand-soil mix. Casing is critical for triggering primordia (pinheads) — this species behaves like button mushrooms in needing a casing layer to initiate fruiting.
Fruiting
Shift to 12–23°C and 90–98% RH with regular watering. First mature fruitbodies appear approximately 30 days after casing colonization, with subsequent flushes around days 37–43 and a final flush around days 48–50. Total cycle 6–8 weeks from spawn to last flush.
Expected Yield
Biological efficiency ranged from 35–41% in Chinese field trials and 3.4–43% in Taiwanese domestication work. Strain choice may matter as much as or more than protocol details. Starting with a known-performance strain is the most important variable the cultivator controls.
What Bioactive Compounds Does Blue Foot Mushroom (Clitocybe sordida) Contain?
Blue Foot Mushroom (Clitocybe sordida) has a richer and more varied chemistry than most species guides acknowledge. The compound profile divides cleanly by source material — culture broth metabolites, fruiting-body polysaccharides, submerged-culture mycelial polysaccharides, and volatile aroma compounds are distinct categories, and the relevant evidence must be organized accordingly rather than merged into a single claim about what "this mushroom contains."
2-Azahypoxanthine (AHX)
1,2,3-Triazine — Culture BrothThe "fairy chemical." First isolated from L. sordida culture broth as the compound responsible for inducing the greening arc around fairy rings. Features an unusual 1,2,3-triazine ring system. Biosynthetic pathway involves nitric oxide synthase and conversion of AICAR to AHX-ribotide, subsequently clarified in a 2022 mechanistic paper. Biological evidence is plant-growth-related, not pharmaceutical.
Mechanistic — plant biologyLSPc1 (Fruiting Body Polysaccharide)
Water-Soluble Polysaccharide — Fruiting BodyThe most bioactive of four water-soluble polysaccharides (LSPa1, LSPb1, LSPb2, LSPc1) isolated from fruiting bodies. MW ~57 kDa. Reduced tumor volume and tumor weight in Hep-2 laryngocarcinoma xenograft mice. Follow-up studies showed it induces G2/M cell-cycle arrest and apoptosis in Hep-2 cells via mitochondrial pathway (Bax/Bcl-2, cytochrome c, caspase-3/-9).
In vitro + mouse xenograftIDO-Inhibiting Polysaccharide (LSP)
α-D-Glucan — Fruiting BodyA ~40 kDa water-soluble fruiting-body glucan inhibited IFN-γ-induced IDO (indoleamine 2,3-dioxygenase) expression and kynurenine production in HepG2 cells via JAK-PKC-δ-STAT1 signaling. IDO suppression improved survival of primary CD4+ and CD8+ T cells in conditioned-medium experiments — a preliminary immune-modulation finding.
In vitroLepistatins A–C
Chlorinated Sesquiterpenes — Culture BrothThree new chlorinated sesquiterpenes isolated from L. sordida culture broth (2017). Structures established by HREIMS and 1D/2D NMR; represent a novel indanone-containing sesquiterpene scaffold derived from trans-humulyl cation cyclization. Structurally significant; bioassay potency data were not fully exposed in the available abstract.
Structure characterized — bioassay pendingSubmerged-Culture Polysaccharides
Mixed Polysaccharides — MyceliumEthanol-fractioned mycelial polysaccharides (40%, 60%, 80% fractions; MW 1.2–224 kDa) showed in vitro antioxidant activity (DPPH IC₅₀ 1.125 mg/mL for 40%-LSP-UMSE) and prebiotic effects on Lactobacillus casei fermentation, raising OD600 by 60–78% versus inulin controls. Importantly, the mycelial and fruiting-body polysaccharide profiles are distinct.
In vitroVolatile Aroma Profile
116 Compounds — Fruiting Body & MyceliumA 2023 HS-SPME-GC-MS study identified 116 volatile compounds total: 91 in mycelium, 66 in fruiting bodies, 40 shared. Key odor-active compounds included 1-octen-3-ol, trans-nerolidol, benzaldehyde, phenylacetaldehyde, and octanal. Characteristic for mycelium: γ-nononolactone. Characteristic for fruiting bodies: pentanoic acid, citral, and 1-octen-3-ol. These correlate with the documented pleasant floral/fruity scent.
Analytical chemistryIs Blue Foot Mushroom (Clitocybe sordida) Safe to Eat?
Blue Foot Mushroom (Clitocybe sordida) is edible when thoroughly cooked — this qualifier matters more for this species than for many edible mushrooms. Multiple field sources report gastrointestinal upset from raw or undercooked specimens, and foraging guides consistently emphasize that cooking is not optional. No species-specific lethal toxin has been identified, and it is consumed as a wild food across Korea, China, Japan, Algeria, central Africa, and parts of Europe.
The safety record has one notable entry: a China CDC outbreak summary from 2019 reported GI symptoms after consumption of Lepista sordida alongside Macrocybe gigantea. These reports are difficult to interpret because they may reflect inadequate cooking, contamination, idiosyncratic reactions, or misidentification rather than a defined species toxin — but the event exists in the literature and belongs in any honest safety section.
The most important practical risk is misidentification. Purple Cortinarius species share the violet coloration and can grow in similar habitats; their rusty-brown spore print versus the pale pinkish-cream of Blue Foot Mushroom (Clitocybe sordida) is the single most important separator. Always take a spore print. Additionally, because this species frequently fruits in lawns, roadsides, and disturbed ground, specimens from heavily trafficked or chemically treated sites may carry environmental contaminants unrelated to the mushroom's own chemistry.
What Makes Blue Foot Mushroom (Clitocybe sordida) Remarkable?
The Fairy Ring Problem — Solved
Fairy rings have fascinated observers since at least medieval times, inspiring folklore about dancing fairies and supernatural circles. In 2010, researchers working with Lepista sordida culture broth isolated 2-azahypoxanthine (AHX) as the compound responsible for the characteristic greening arc. The unusual 1,2,3-triazine ring system of AHX had no known biosynthetic precedent; a 2022 mechanistic paper then characterized the nitric oxide synthase-linked pathway through AICAR — making Blue Foot Mushroom the species that finally explained a centuries-old phenomenon.
Genomic Depth Unusual for an Edible Mushroom
Blue Foot Mushroom (Clitocybe sordida) / Lepista sordida has a draft genome of 39.0 Mb (703 scaffolds, 44.9% GC; DDBJ/GenBank BIMQ01000001+), a domesticated-strain genome of 40.67 Mb (13 contigs, 46.35% GC), and a complete mitochondrial genome of 57,375 bp encoding 20 protein-coding genes, 2 rRNAs, and 26 tRNAs. Comparative proteomics has been published on domestication responses. Very few edible agarics outside lion's mane and oysters have this level of genomic characterization.
Strain Variation as a Research Front
The 40-fold variation in biological efficiency across strains (3.4% to 43%) documented in published cultivation trials is not merely a practical inconvenience — it represents genuine biological variation worth studying. Comparative proteomics analysis has already begun to characterize what differs between domesticated and wild strains, and the genomic resources now exist to pursue QTL-level or gene-expression-level analysis of yield-relevant traits. This makes Blue Foot Mushroom (Clitocybe sordida) an unusually tractable model for mushroom domestication science.
Three Naming Systems in Active Use
Few commercially relevant mushrooms sit at the center of an active nomenclatural debate quite like this one. The same organism is simultaneously listed as Lepista sordida in most of the peer-reviewed chemistry and cultivation literature, Clitocybe sordida in MycoBank, and Collybia sordida in iNaturalist and increasingly in field communities — with a 2025 phylogenetic study adding further resolution. This is not sloppiness; it reflects genuine ongoing revision of clitocyboid phylogenetics that most consumer-facing content either ignores or misrepresents.
Documented Food Use on Four Continents
Wild food surveys from central Africa (Benin, Democratic Republic of Congo, Rwanda), China, Japan, Korea, Algeria, Brazil, and Europe all include Blue Foot Mushroom (Clitocybe sordida) / Lepista sordida as a consumed species. Few temperate agarics have documented food-use records this geographically distributed. The species' cosmopolitan temperate distribution and compost/lawn habitat — bringing it into regular human contact — likely explains this breadth.
Heat Stress Genomics
A 2025 comparative genomics study specifically examined mechanisms of response to heat and other environmental stresses in Lepista sordida, using the domesticated strain to probe primordium differentiation pathways and substrate utilization. This is the level of genomic investment normally reserved for model organisms or high-value commercial species — an indication that the scientific community views this mushroom as more than a minor blewit relative.
Frequently Asked Questions About Blue Foot Mushroom (Clitocybe sordida)
Is Blue Foot Mushroom the same as Sordid Blewit or Lepista sordida?
Yes — Blue Foot Mushroom, Sordid Blewit, Dirty Blewit, Blue Leg, Pied Bleu, Lepista sordida, Clitocybe sordida, and Collybia sordida all refer to the same fungal organism. The variation in names reflects both regional common-name usage and an active nomenclatural debate among taxonomists. The majority of peer-reviewed science (cultivation protocols, chemistry, genomics) uses Lepista sordida. Current databases and field communities increasingly prefer Clitocybe sordida or Collybia sordida. Out-Grow's products use Clitocybe sordida.
Can Blue Foot Mushroom (Clitocybe sordida) be cultivated at home?
Yes, with caveats. Unlike ectomycorrhizal species, Blue Foot Mushroom (Clitocybe sordida) is saprotrophic and can be cultivated without a tree partner. Peer-reviewed trials have achieved biological efficiency of 35–43%. The key requirements are compost-based substrate (not simple sterilized grain or sawdust), a casing layer, cool fruiting temperatures (12–23°C), and high humidity (90–98%). Performance is highly strain-dependent — the same protocol yielded 3.4% BE in one strain and 43% in another. A quality liquid culture from a known-performance strain is the most important starting point.
What does Blue Foot Mushroom (Clitocybe sordida) taste and smell like?
The scent is reliably pleasant — described as floral, fruity, perfumed, or mildly sweet, distinctly non-farinaceous (not floury or mealy). This aromatic quality has been analytically characterized: a 2023 GC-MS study identified 116 volatile compounds, with citral, pentanoic acid, and 1-octen-3-ol as the characteristic odor-active compounds in fruiting bodies. The taste is mild; the texture is firm when young. It is described as a choice edible in East Asian culinary contexts.
What is the fairy-ring connection to Blue Foot Mushroom (Clitocybe sordida)?
Blue Foot Mushroom (Clitocybe sordida) — published as Lepista sordida in the original research — was the organism through which the biochemical mechanism of fairy rings was first characterized. In 2010, 2-azahypoxanthine (AHX) was isolated from its culture broth and shown to be the compound responsible for the characteristic arc of stimulated green grass around fairy rings. The biosynthetic pathway was subsequently worked out in 2022, involving nitric oxide synthase and the AICAR precursor. Most online sources describe the fairy-ring pattern as mysterious; this mushroom is the reason it no longer is.
Is Blue Foot Mushroom (Clitocybe sordida) safe to eat raw?
No — thorough cooking is required. Multiple field guides and foraging sources note that raw or undercooked specimens cause gastrointestinal upset. A 2019 China CDC report documented GI symptoms following consumption, though interpreting such reports is complex (preparation, contamination, and misidentification are confounding factors). There is no identified species-specific lethal toxin, but "edible when cooked" should not be read as "safe raw." Standard precautions — accurate identification, thorough cooking, moderate initial serving — apply.
How does Blue Foot Mushroom (Clitocybe sordida) differ from Wood Blewit?
Wood Blewit (Lepista / Clitocybe nuda) is the larger, more familiar relative. The key differences: Wood Blewit is bigger (cap up to 15 cm), fleshier, retains violet color more uniformly without fading from center, prefers woodland leaf litter, and has a less hygrophanous cap. Blue Foot Mushroom (Clitocybe sordida) is smaller and thinner-fleshed, fades visibly from center-outward as it dries, prefers open ground and compost, and often grows in pronounced fairy rings. Both are edible when cooked, and both belong to the same genus complex — currently undergoing active taxonomic revision.
Also available as a culture plate from Out-Grow.
Blue Foot Mushroom (Clitocybe sordida) Culture Plate