Gold Enoki (Flammulina velutipes)
Gold Enoki (Flammulina velutipes)
Gold Enoki (Flammulina velutipes) is a cold-loving, wood-rotting fungus native to the temperate forests of Europe, Asia, and North America, recognized worldwide as both a foraged wild edible. In the wild it fruits as dense clusters of rich tawny-orange caps on dead elm and hardwood throughout winter, while commercial production — yielding more than a million tonnes annually — produces the long-stemmed, pale white clusters familiar in global supermarkets. Its cultivation history stretches back to at least 800 AD in China, making it arguably the world's oldest continuously cultivated gourmet mushroom.
Flammulina velutipes (Curtis) Singer — Physalacriaceae — Agaricales
Gold Enoki (Flammulina velutipes) occupies a singular position in the fungal world: the same genetic organism produces the gorgeous amber wild clusters that seasoned foragers seek on winter elm stumps in England, and the ghostly white needle-like tufts sold in vacuum packs across Asia and North America. This extreme morphological flexibility — driven entirely by light, temperature, and CO₂, not genetics — makes it one of mycology's most instructive examples of how environment shapes form. It is also one of the richest fungal sources of ergothioneine (a potent antioxidant), contains structurally novel sesquiterpenes, and its genome encodes more carbohydrate-degrading enzymes than any comparable wood-decay fungus sequenced to date.
Interested in this species? Out-Grow carries a liquid culture.
Gold Enoki (Flammulina velutipes) Liquid CultureWhat Is the Gold Enoki (Flammulina velutipes)?
The Gold Enoki (Flammulina velutipes) is a basidiomycete — a spore-bearing fungus in the same broad group as button mushrooms, shiitake, and oysters — that breaks down dead hardwood through white rot, dissolving both cellulose and lignin (the two main structural polymers of wood). It belongs to the family Physalacriaceae (order Agaricales), placing it in the Marasmioid clade alongside honey fungi (Armillaria) and shiitake (Lentinula edodes). Unlike those relatives, enoki fruits prolifically through the coldest months of the year, often continuing to develop and release spores after freezing solid and thawing — a feat made possible by specialized antifreeze polysaccharides in its cell walls.
In the wild, the species is most reliably identified by three simultaneous features: a slimy, reddish-brown to tawny-orange cap; a distinctively velvety, nearly black stipe base; and winter fruiting in dense clusters on dead or dying hardwood, particularly elm. Wild enoki collected from the hedgerows of Britain or the forests of Central Europe bears little obvious resemblance to the commercial product, yet both represent the same species expressing radically different developmental programs under different environmental conditions.
The Most Important Thing Almost Every Enoki Article Gets Wrong: The pale white enoki sold in global supermarkets is now understood to be predominantly Flammulina filiformis — a species formally separated from F. velutipes in 2018 by multilocus molecular analysis. Most cultivation data, bioactivity research, and food chemistry literature was produced using East Asian strains now assigned to F. filiformis rather than F. velutipes sensu stricto. This guide covers the Flammulina velutipes species complex broadly, noting where data applies specifically to commercial F. filiformis strains.
Commercial enoki cultivation exceeds one million tonnes annually, with China holding the largest production share. The mushroom's cultivation history in China begins around 800 AD, predating systematic cultivation of most other commercial species by centuries. Japan modernized bottle cultivation techniques in the 1960s, and the industrial protocol developed there — sealed bottles, elevated CO₂, darkness, cold — remains the global standard for producing the characteristic slender white product.
How Is the Gold Enoki (Flammulina velutipes) Classified?
The accepted name Flammulina velutipes (Curtis) Singer was published in Lilloa 22: 307 (1951). The basionym — the original name on which the current name is based — is Agaricus velutipes Curtis (1782), described by English botanist William Curtis in Flora Londinensis. Rolf Singer transferred it to the genus Flammulina in 1951; the sanctioning author is Fries (Fr.), which stabilizes the name under the dual nomenclature system for fungi. Flammulina is derived from the Latin flamma (flame), referencing the warm orange color of wild fruiting bodies. Velutipes means "velvet foot" in Modern Latin — a direct reference to the distinctive fuzzy, dark stipe base.
| Rank | Name |
|---|---|
| Kingdom | Fungi |
| Phylum | Basidiomycota |
| Class | Agaricomycetes |
| Order | Agaricales |
| Family | Physalacriaceae |
| Genus | Flammulina |
| Species | Flammulina velutipes (Curtis) Singer |
| MycoBank ID | 10374 |
| Index Fungorum ID | 330940 |
| NCBI Taxonomy ID | 38945 |
Notable synonyms reflect the species' journey through different genus concepts over two centuries. It was long placed in Collybia as Collybia velutipes (Curtis) P.Kumm., an obligate synonym still cited in older literature. Other historical names include Agaricus nigripes Bull. (named for the dark stipe), Gymnopus velutipes, and Myxocollybia velutipes. These synonyms reflect shifting genus-level concepts rather than true taxonomic disputes about the organism itself.
The current major taxonomic issue is the species complex surrounding F. velutipes. A 2018 multilocus study using ITS, LSU, and RPB2 markers combined with morphology and mating tests formally separated East Asian cultivated strains as Flammulina filiformis and described Flammulina finlandica from northern Europe. Earlier work had separated F. populicola (on poplar roots) and F. rossica. The genus now contains approximately 15 recognized species, and ITS alone cannot reliably distinguish them — a multilocus phylogeny is the current gold standard.
How Do You Identify the Gold Enoki (Flammulina velutipes)?
Wild Gold Enoki (Flammulina velutipes) has a distinctive and consistent appearance that separates it from most other winter species. The key identifying features must be evaluated together — no single feature is sufficient.
The velvety black stipe base — darker toward the base, paling to orange-brown near the cap — is the single most reliable macroscopic identification feature among common winter species. No ring (annulus) is present at any developmental stage. Young specimens have uniformly pale stipes; the dark velvet develops progressively from the base upward as the mushroom matures.
Lookalike Species
Contains amatoxins. Always has a ring on the stem and a rusty-brown spore print. Usually lacks the slimy cap and grows more often in summer–autumn. Spores are amyloid (turn blue-black in Melzer's reagent) and significantly larger: 8–10 × 5–6 µm. Take a spore print before consuming any wild mushroom in this group — a white print rules out Galerina immediately.
Causes gastrointestinal illness. Distinguished by yellow-green gills (never white), distinctly bitter taste, and purple-brown spore print. Grows primarily summer–autumn, though can overlap with winter enoki. Clusters are often more tightly packed and shorter-stemmed.
Has a dry, non-slimy cap and produces a rusty-orange spore print. Distinguished from enoki by its bitter taste and warm brown-orange gills. Grows June–December on conifer wood primarily.
Closely related species found in Europe. Distinguished primarily by molecular analysis; morphologically very similar to F. velutipes. Considered edible. The existence of this and other recently described Flammulina species underscores the importance of geographic context when identifying wild specimens.
Critical Rule: Always take a spore print before consuming wild enoki. A white spore print combined with an absent ring and a slimy cap on winter wood is strongly diagnostic for Flammulina. A rusty-brown spore print means stop — do not eat.
Where Does the Gold Enoki (Flammulina velutipes) Grow?
Gold Enoki (Flammulina velutipes) is a white-rot saprotrophic fungus — meaning it breaks down both cellulose and lignin (the structural polymers of wood), leaving the wood pale and fibrous as it consumes it. This ecological mode allows it to fruit on any dead lignocellulosic substrate without requiring a living tree partner, which is precisely why it can be cultivated in isolation on agricultural byproducts.
In the wild, the species preferentially colonizes dead or dying hardwoods, with elm (Ulmus spp.) cited most frequently — particularly trees weakened by Dutch elm disease, whose fungal pathogen creates prime substrate for saprotrophic colonization. Other documented host trees include ash (Fraxinus), beech (Fagus), oak (Quercus), willow (Salix), poplar (Populus), birch (Betula), maple (Acer), and plum (Prunus). In coastal Northern California, enoki is notably common on senescent bush lupine (Lupinus arboreus) — a dramatically different substrate from its European woodland context.
| Region | Season | Primary Substrate | Notes |
|---|---|---|---|
| Europe | October – April | Elm, beech, ash | Peak in winter thaws; sometimes seen through April |
| North America (East) | November – May | Elm, oak, maple | Fruits during winter thaws; persists into spring |
| North America (West) | Variable | Oak, bush lupine | Notable on coastal California lupine |
| East Asia (wild) | October – March | Diverse hardwoods | Wild form; commercial strains are F. filiformis |
| Scotland / Northern Europe | December – April | Elm, willow, gorse | Cold climate extends the season; fruiting after snow |
The IUCN Global Fungal Red List Initiative classifies F. velutipes as globally widespread with no evidence of population decline — it has no red-list designation anywhere in its range. Cold temperatures actively trigger fruiting: this is not a species that reluctantly tolerates winter but one that genuinely requires it. The ability to freeze solid, thaw completely, and resume spore production is a well-documented physiological adaptation discussed further in the Unique Biology section below.
Can You Cultivate the Gold Enoki (Flammulina velutipes)?
Gold Enoki (Flammulina velutipes) is one of the most extensively cultivated mushrooms in the world — fully domesticated, requiring no living host, and producing reliable yields on agricultural substrates. The cultivation biology of this species is well-documented from both commercial and hobbyist perspectives, and the liquid culture pathway is a genuinely practical starting point for home cultivators.
Agar and Liquid Culture Behavior
On agar (such as PDA, PDYA, or Malt Yeast Agar), dikaryotic Flammulina mycelium is white, longitudinally linear, and becomes finely appressed (pressed flat) with age. Older colonies develop characteristic golden-yellow spotting or zonation — a visual trait that helps confirm culture identity. One behavior particularly useful for cultivators: in cold storage or low-temperature incubation, colonies will frequently initiate primordia (tiny fruiting initials) along the inside perimeter of the Petri dish — a cold-triggered developmental response not seen in most cultivated species.
Liquid culture for Flammulina is well-established. The mycelium produces pellets or dispersed growth depending on aeration and agitation. Out-Grow's liquid culture syringe delivers actively growing mycelium ready for transfer to grain spawn, agar plates, or directly to prepared substrate — allowing cultivators to skip the contamination risk of agar work if preferred. Optimal mycelial pH range for growth spans 4.0–7.0; substrate pH optimum is 5–6 for fruiting.
About the Out-Grow Enoki Liquid Culture
Out-Grow's Gold Enoki (Flammulina velutipes) liquid culture syringe contains actively growing mycelium suspended in a sterile nutrient solution. It can be used to inoculate grain spawn jars (rye, wheat, or sorghum are all suitable), agar plates for culture expansion, or directly into prepared sawdust substrate. Liquid culture inoculation distributes evenly throughout grain, resulting in faster initial colonization than agar wedge transfer. Store unused culture refrigerated and use within two weeks of receipt for best results.
Spawn Run Parameters
Primordia Initiation
Fruiting and Stem Elongation
The critical cultivation insight: elevated CO₂ is the primary driver of the "enoki phenotype" — the long-stemmed, small-capped, pale white form. Reducing CO₂ and increasing fresh air exchanges (FAE, meaning fresh air exchanges per hour) will produce a more natural morphology with wider, more pigmented caps. Home cultivators growing with increased fresh air will get a product that looks more like wild velvet shank than commercial enoki — and many find it more visually striking.
Substrates and Biological Efficiency
Optimal substrate carbon-to-nitrogen (C/N) ratio is 27:1. Sawdust supplemented with rice bran is the standard Japanese commercial substrate; paddy straw combined with palm-based materials achieves biological efficiency above 180% in published trials. Bottle cultivation (600–700 mL bottles) yields approximately 200 g fresh weight per bottle under commercial conditions. The entire commercial cycle from inoculation to harvest runs approximately 55 days.
Contamination Risks
Green molds (Trichoderma spp.) are the universal mushroom cultivation contaminant and the primary risk for Flammulina. Sterilization failure is the most common cause. Bacterial contamination with Lactococcus lactis has been documented in commercial fruiting bodies. Listeria monocytogenes is a food safety concern in commercial enoki — discussed in detail in the Safety section below. High-nitrogen substrate supplements (rice bran, soybean meal) increase contamination risk if sterilization is incomplete.
Full Commercial Cycle Overview
Substrate Preparation
Mix sawdust, rice bran, and supplements to target C/N ratio of 27:1. Sterilize at 121°C for adequate duration.
Inoculation
Inoculate with liquid spawn or grain spawn. Liquid spawn distributes more evenly, reducing lag at colonization front.
Spawn Run
Hold at 21–24°C for 14–18 days. High CO₂ and minimal FAE. Full white mycelial colonization throughout substrate.
Tickling
Mechanical surface scarification breaks up surface mycelium and stimulates uniform primordia initiation.
Cold Induction
Drop temperature to 7–10°C. This cold shock is non-negotiable — enoki will not initiate primordia without it.
Elongation and Harvest
Hold at 7–13°C with elevated CO₂ for long-stem development. Harvest when caps are still small and closed.
What Bioactive Compounds Does the Gold Enoki (Flammulina velutipes) Contain?
Gold Enoki (Flammulina velutipes) contains a chemically diverse array of bioactive molecules — proteins, polysaccharides, sesquiterpenes, phenolics, and a notable natural statin. Evidence quality varies substantially between compound classes, and this section is explicit about what level of evidence supports each claim.
FIP-fve (Fungal Immunomodulatory Protein)
Animal ModelA 12.74 kDa homodimer with a novel fibronectin III fold (crystal structure PDB: 1OSY). Stimulates T-cell and B-cell activity; at 11 mg per 100 g fresh fruiting body. Oral administration in mice activates anti-tumor immunity. No human trials published.
Ergothioneine
In VitroA thiohistidine betaine antioxidant present at 3.03 mg/mL in fruiting body extract — one of the highest concentrations among all mushroom species tested. Highest levels in the stem base and mycelium. DPPH scavenging ~85–90%; strong antioxidant activity in multiple assay formats.
β-Glucan Polysaccharides
Animal ModelAlkaline-soluble β-(1→3)-D-glucan (~200 kDa) from the fruiting body cell wall. In mouse models, 94.1–97.8% inhibition of SC-180 sarcoma at 15 mg/kg i.p. Stimulates splenic lymphocyte proliferation in vivo. No human clinical data.
Enokipodins A–D
In VitroNovel antimicrobial sesquiterpenes produced in mycelial culture filtrate. Activity against gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus). Minimum inhibitory dose for enokipodins A and C against B. subtilis comparable to penicillin G in laboratory assays.
Proflamin
Animal ModelGlycoprotein (13 kDa) from mycelium. Oral antitumor activity in mice: at 10 mg/kg, increased median survival time for B-16 melanoma by 86%. Acts via host immune modulation, not direct cytotoxicity. Studied as a pharmaceutical candidate in Japan in the 1980s; no human trials completed.
Flammulinolides A–G
In VitroNorditerpenes with anticancer activity in cell lines. Flammulinolide A, B, F: IC₅₀ ~3.6–4.7 µM against KB cells; Flammulinolide C: IC₅₀ ~3.0 µM against HeLa cells. IC₅₀ (half-maximal inhibitory concentration) = the compound concentration that kills 50% of cells in vitro.
Lovastatin
Animal ModelThe well-characterized cholesterol-lowering statin detected in fruiting bodies at 90.8 ± 2.0 mg/kg dry weight. Total cholesterol reductions of 21–29% documented in animal models. The naturally occurring statin in this mushroom is pharmacologically identical to the prescription drug form.
Antifreeze Polysaccharides
In VitroMannose + xylose polymers that demonstrate strong ice recrystallization inhibition (IRI — preventing small ice crystals from merging into larger damaging ones). First documented mushroom-derived cryoprotectant of practical food industry interest.
Flammulin (Ribosome-Inactivating Protein)
In Vitro40 kDa protein; IC₅₀ of 0.25 nM for inhibiting cell-free translation — among the most potent RIPs (ribosome-inactivating proteins) characterized from any fungal source. Food safety relevance unclear; likely denatured by cooking.
On nutritional composition: dry matter is 93–119.5 g/kg fresh weight (approximately 90% water). On a dry weight basis, carbohydrates constitute 42.6–87.1%, protein 17.9–27.95%, and fat 1.7–7.3%. Linoleic acid dominates the fatty acid profile at 40.93–56.33% of total fatty acids. Potassium is the most abundant mineral at 28.00–28.98 mg/g dry weight.
Is Gold Enoki (Flammulina velutipes) Safe to Eat?
Gold Enoki (Flammulina velutipes) is a well-established edible mushroom with a centuries-long culinary record and no documented toxicity from normal cooked consumption. However, there are two important safety areas that require clear explanation: the heat-sensitive toxin in raw fruiting bodies, and the documented bacterial contamination issue in commercial enoki.
Flammutoxin — Present Raw, Eliminated by Cooking
Raw Flammulina velutipes fruiting bodies contain flammutoxin (FTX), a cardiotoxic, pore-forming protein present at ~452 µg/mL in cold water extract. In laboratory settings, flammutoxin assembles into ring-shaped oligomers on cell membranes, causing potassium efflux, osmotic swelling, and hemolysis (rupture of red blood cells). It is cardiotoxic in isolated cell and animal injection assays.
The critical safety context: flammutoxin is heat-labile, meaning it denatures (loses its structure and function) at 60°C — well below boiling. Standard cooking eliminates the toxin. No documented human poisoning case from cooked F. velutipes exists in the reviewed literature. Do not eat this mushroom raw. Cook it thoroughly before consumption.
Listeria monocytogenes — A Real and Ongoing Food Safety Issue
Listeria monocytogenes is a cold-tolerant bacterial pathogen that has repeatedly contaminated commercially produced enoki mushrooms, primarily from East Asian production facilities. Key documented incidents include a 2020 US outbreak (36 illnesses, 31 hospitalizations, 4 deaths) linked to Korean-imported enoki; a 2021 FDA finding that 42% of sampled Korean enoki tested positive for Listeria; a January 2026 Canadian recall of Mushmoshi brand enoki for Listeria; and a March 2026 outbreak resulting in hospitalizations in Michigan and Nevada. Cooking at standard temperatures (above 70°C) eliminates Listeria risk. Raw enoki should not be consumed by pregnant women, immunocompromised individuals, or people over 65.
Safety Summary: Cooked Flammulina velutipes is a safe, well-tolerated edible mushroom for healthy adults. The two risks — flammutoxin and Listeria — are both eliminated by cooking. Never eat raw enoki from any source.
What Makes Gold Enoki (Flammulina velutipes) Remarkable?
Gold Enoki (Flammulina velutipes) is unusually rich in genuinely remarkable biology — the kind of content that exists in peer-reviewed journals but has never been synthesized accessibly for a general mycological audience.
The Freeze-Thaw Organism
Flammulina velutipes can freeze completely solid in winter storms and, upon thawing, resume active development and spore release. This is not a passive tolerance — it is mechanistically supported by specialized antifreeze polysaccharides (mannose + xylose polymers) that have recently attracted interest from food scientists as natural cryoprotectants. The mechanism differs fundamentally from antifreeze proteins found in fish and insects: rather than lowering the freezing point through thermal hysteresis, the Flammulina polysaccharides prevent ice recrystallization — the process by which small ice crystals merge into large, cell-damaging ones. This makes them a potential commercial ingredient for protecting food quality through freeze-thaw cycling.
One Species, Two Completely Different Mushrooms
The transformation from wild velvet shank (a squat, tawny-orange cluster on dead elm) to commercial enokitake (a cluster of ghostly white needles up to 15 cm long) is not genetic engineering or selective breeding in the conventional sense. It is pure phenotypic plasticity — the same genetic information expressing a completely different developmental program in response to three environmental variables: darkness eliminates pigment synthesis (producing the white color), elevated CO₂ drives stipe elongation by disrupting gravitropic responses, and physical confinement in a bottle directs upward growth. Restore normal light, fresh air, and space, and the same strain grows brown and cap-dominant again. The 2014 genome study found that 2% of the F. velutipes genome is expressed exclusively in fruiting bodies, with many of these genes having no homologs in any other organism — suggesting substantial unexplored developmental biology in this species.
The Largest Wood-Decay Enzyme Arsenal Known
The F. velutipes genome (35.6 Mb, sequenced 2014, GenBank AQHU00000000) encodes 392 CAZymes — carbohydrate-active enzymes that break down complex sugars — the highest count documented among comparable basidiomycetes at time of publication. It also carries 23 polysaccharide lyases and 91 carbohydrate esterases, both the highest numbers in any comparable genome. Alongside this, 58 alcohol dehydrogenase genes enable direct ethanol production from wood sugars — a capacity under active investigation for converting agricultural waste into biofuels without pre-processing. A mushroom sold in supermarkets as a noodle soup topping is simultaneously a potential biorefinery platform organism.
The Oldest Continuously Cultivated Gourmet Mushroom
Flammulina velutipes holds a credible claim to being the world's longest-continuously-cultivated edible mushroom, with documented Chinese cultivation records dating to 800 AD. This predates systematic cultivation of shiitake, oyster mushrooms, and virtually every other commercial gourmet species by centuries. The transition from log cultivation in China to the modern bottle cultivation system developed in Japan in the 1960s represents one of the most successful examples of applied mycology in industrial food production.
A Structurally Novel Protein Fold
FIP-fve, the fungal immunomodulatory protein isolated from enoki fruiting bodies, has a crystal structure (PDB: 1OSY, solved at 1.7 Å resolution) that represents an entirely novel protein fold — an N-terminal alpha-helix followed by a fibronectin III domain in a "pseudo-h-type" topology not previously described in any organism. This structural novelty has implications for understanding how a whole family of fungal immunomodulatory proteins evolved and function.
Frequently Asked Questions About Gold Enoki (Flammulina velutipes)
Is Gold Enoki the same as velvet shank?
They are closely related but the full answer requires nuance. Wild velvet shank (Flammulina velutipes sensu stricto) and commercial enokitake are the same or closely related species expressing dramatically different morphologies under different growing conditions. However, a 2018 molecular study formally separated most East Asian cultivated and wild "enoki" strains as a distinct species: Flammulina filiformis. The commercial enoki in supermarkets is now taxonomically F. filiformis in most cases, while the European wild velvet shank is F. velutipes sensu stricto. In practical culinary and cultivation contexts, the distinction matters less than in scientific literature.
Why does Gold Enoki look so different in the store compared to the wild?
Commercial enoki is grown in dark, sealed bottles with elevated carbon dioxide and minimal fresh air. Darkness eliminates the pigment synthesis that creates the brown-orange color in wild specimens. High CO₂ triggers dramatic stipe elongation by disrupting normal growth responses. The same mushroom grown with natural light and fresh air will develop as wide-capped, brown, and squat — nearly unrecognizable as the same organism. This is phenotypic plasticity, not selective breeding.
Is Gold Enoki safe to eat raw?
No. Raw Flammulina velutipes fruiting bodies contain flammutoxin, a cardiotoxic pore-forming protein. Flammutoxin is heat-labile and denatured at 60°C — standard cooking eliminates it entirely. Additionally, commercially produced enoki has been repeatedly implicated in Listeria monocytogenes outbreaks, including fatalities in 2020 and ongoing incidents through 2026. Always cook enoki thoroughly before eating. Do not serve raw enoki to pregnant women, older adults, or immunocompromised individuals.
What substrate should I use to grow Gold Enoki at home?
Sterilized grain spawn (rye, wheat, or sorghum) is the standard starting substrate for inoculation with liquid culture. For fruiting, supplemented hardwood sawdust is optimal — sawdust from oak, beech, or mixed hardwoods works well. The target C/N (carbon-to-nitrogen) ratio in the substrate is 27:1. Paddy straw combined with palm-based materials achieves very high biological efficiency in published research. A key environmental requirement: enoki requires a significant temperature drop to 7–10°C to initiate primordia — a cold stage that cannot be skipped.
Does Gold Enoki have medicinal properties?
Gold Enoki (Flammulina velutipes) contains several biologically active compounds — FIP-fve (an immunomodulatory protein), polysaccharides with anti-tumor activity in mouse models, ergothioneine (a potent antioxidant), lovastatin (a natural statin), and novel sesquiterpenes with in vitro anticancer activity. However, the honest evidence assessment is that no robust human randomized controlled trials have been published for any Flammulina compound. The preclinical evidence is scientifically interesting and mechanistically plausible, but these findings cannot be described as clinically proven health benefits.
Can I grow wild-type Gold Enoki at home instead of the white commercial form?
Yes. The wild-type morphology — wider caps, brown-orange pigmentation, shorter stems — is simply the result of growing with adequate fresh air exchanges and standard light levels. Reduce CO₂ by increasing fresh air, provide some indirect light during fruiting, and maintain temperature at 7–13°C. The same liquid culture used for commercial-style enoki will produce natural-form fruiting bodies under these modified environmental conditions. Many home cultivators prefer the appearance and find the flavor more complex.
Also available as a culture plate from Out-Grow.
Gold Enoki (Flammulina velutipes) Culture Plate