Fee's Polypore (Fomitopsis feei)
Fomitopsis feei
Fomitopsis feei is a bracket polypore fungus native to tropical and subtropical forests across South America, Southeast Asia, South Asia, and Australia, where it grows on. It is most recognizable by its pinkish pore surface — a feature so unusual in polypores that it anchors every field identification — and by the distinctive cherry-red to black reaction its flesh produces when touched with potassium hydroxide. Scientifically, it has attracted attention for three newly described antiviral and antibacterial triterpenoid compounds, a richly productive exopolysaccharide in liquid fermentation, and an extraordinary life-history twist: it has been isolated from inside the living leaves of oil palm, making it among the very few bracket polypores documented as a plant endophyte.
Fomitopsis feei (Fr.) Kreisel — Fomitopsidaceae — Polyporales
Fomitopsis feei (Fee's Polypore) is a pantropical bracket fungus that has been collected in Venezuela, Brazil, India, the Philippines, Thailand, Indonesia, and Australia — always on the dead or dying wood of hardwood trees, never on conifers. Its scientific name honors Antoine Laurent Apollinaire Fée (1789–1874), a French botanist and pharmacist, and its classification has been contested, rewritten, and settled over nearly 200 years of mycological debate. Today it stands as a species with a modest but growing research profile: three novel triterpenoid compounds with antiviral and antibacterial activity in laboratory assays, a well-characterized exopolysaccharide (a complex sugar released into its growing medium) with broad antimicrobial action, and documented potential for submerged liquid culture fermentation — which is how Out-Grow offers it to researchers, cultivators, and mycology enthusiasts.
Interested in this species? Out-Grow carries a liquid culture.
Fomitopsis feei (Fee's Polypore) Liquid CultureWhat Is Fomitopsis feei (Fee's Polypore)?
Fomitopsis feei (Fee's Polypore) is a saprotrophic brown-rot fungus — one that feeds on dead wood by breaking down cellulose and hemicellulose rather than lignin, leaving the characteristic brown, crumbly, cuboid residue that distinguishes brown rot from white rot. It produces hard, shelf-like or hoof-shaped brackets (called basidiocarps or conks) that attach directly to wood without a stalk, growing outward from the substrate surface in the sessile form typical of most polypores.
What sets Fomitopsis feei (Fee's Polypore) apart from the hundreds of other bracket polypores in the family Fomitopsidaceae is its pore coloration. The underside of a fresh specimen is distinctly pinkish to pale rose — a diagnostic character visible in the field — with round pores at a density of 6–8 per millimeter. This pink pore surface is shared with only a handful of related tropical species and is, in practical terms, the fastest way to narrow a field identification to the correct cluster of species.
Key fact: When you apply a drop of potassium hydroxide (KOH) solution to the cut flesh of Fomitopsis feei, the tissue turns cherry red to black. This color reaction is a reliable confirmatory test in the field and in the laboratory, and it distinguishes F. feei from other pinkish polypores that lack this response.
The species is not edible in any conventional sense — its flesh is leathery when fresh and becomes woody and rock-hard when dry, making it physically impossible to eat. This is typical of the Fomitopsidaceae polypores, which are studied not for culinary value but for ecology, wood decomposition biology, and bioactive chemistry. Fomitopsis feei (Fee's Polypore) falls squarely into that research profile: a scientifically interesting, practically non-edible bracket fungus whose value lies in what it produces chemically and how it behaves biologically.
A note on common names: "Fee's Polypore" appears on Out-Grow's product pages and in a small number of informal online contexts, but it does not appear in any peer-reviewed paper, field guide, or regional mycological checklist. It is best understood as a vendor convenience name rather than an established vernacular. The scientific name Fomitopsis feei is the primary search term in all academic literature, iNaturalist, GBIF, and GenBank records. Both names are used here; the scientific name leads because it is the form with meaningful search presence.
How Is Fomitopsis feei (Fee's Polypore) Classified?
The taxonomy of Fomitopsis feei (Fee's Polypore) is one of the more interesting stories in contemporary mycological systematics — a species described in 1830, renamed multiple times, briefly given its own genus in 2016, and returned to Fomitopsis in 2024 following a landmark phylogenetic revision.
| Rank | Name |
|---|---|
| Kingdom | Fungi |
| Phylum | Basidiomycota |
| Class | Agaricomycetes |
| Order | Polyporales |
| Family | Fomitopsidaceae |
| Genus | Fomitopsis |
| Species | Fomitopsis feei (Fr.) Kreisel |
Elias Fries, the Swedish mycologist who effectively founded modern fungal nomenclature, first described this species in 1830 as Polyporus feei in the journal Linnaea, naming it for Antoine Fée. In 1971, Kreisel transferred it to Fomitopsis — the accepted placement for the next four decades.
In 2016, a six-gene molecular phylogenetic study by Han et al., published in Fungal Diversity, found that the pinkish-pored tropical polypores (including F. feei) formed a distinct genetic cluster outside the core Fomitopsis clade. Han et al. created a new genus, Rhodofomitopsis (from the Greek rhodon, meaning rose, for the characteristic pore color), with F. feei as its type species. For roughly eight years, the species was formally called Rhodofomitopsis feei.
2024 revision: Spirin, Runnel, Vlasák et al. published a comprehensive revision of Fomitopsidaceae in Studies in Mycology 107, arguing that fragmenting the family into dozens of small genera created an unstable, impractical classification. They synonymized Rhodofomitopsis and approximately twenty other genera back into a broadly defined Fomitopsis containing 128 species. The accepted name reverted to Fomitopsis feei (Fr.) Kreisel. MycoBank number: #283457.
As of early 2026, databases are not synchronized on this revision. iNaturalist has adopted Spirin et al. (2024); GBIF still lists Rhodofomitopsis feei as an accepted name; NCBI carried the old name through early 2025. Researchers working with this species should check each database independently and note which taxonomic framework applies. The family Fomitopsidaceae is consistently applied across all databases regardless of genus-level disagreement.
The synonymy list is long — reflecting the typical turbulence of pantropical bracket polypores collected and renamed across continents over two centuries. Major synonyms include Polyporus feei Fr. (basionym), Polyporus sagraeanus Mont., Fomes feei (Fr.) J. Lowe, Trametes feei (Fr.) Pat., Rhodofomitopsis feei (Fr.) B.K. Cui et al., and Pseudofomitopsis pseudofeei B.K. Cui & Shun Liu (synonymized by Spirin et al. 2024).
How Do You Identify Fomitopsis feei (Fee's Polypore)?
Field identification of Fomitopsis feei (Fee's Polypore) relies on a combination of macroscopic characters — none individually definitive — converging on a profile. Confirmation, especially to separate it from closely related pink polypores, requires either microscopy or molecular sequencing.
Macroscopic Morphology
The pinkish pore surface is the most important field character. Fresh specimens show a clean pale-pink to rose-buff underside; this fades with age and drying to beige or dirty brown. The cap surface shows concentrically zoned ridges and may be smooth to minutely velvety. Older specimens can develop a brownish-ochre crust that obscures the original tints. Critically, specimens lacking the pink and lilac tints can be very difficult to identify in the field — the fresh cross-sectioned flesh, which retains rose-brown coloration longer than the surface, is often the better character to check.
Microscopic Features
Basidiospores (the reproductive cells) of Fomitopsis feei are subfusiform — narrowly spindle-shaped — smooth, thin-walled, and hyaline (transparent). Dimensions: 6–8 × 1.5–2 μm. The Q ratio (length divided by width) is approximately 3–4.5, which is notably high for the Fomitopsidaceae family and is the primary microscopic character separating F. feei from its closest lookalikes. Basidia (spore-bearing cells) are clavate (club-shaped) and four-spored: 10–21 × 3.5–7 μm. Cystidia (sterile cells in the spore-bearing layer) are absent. The hyphal system is dimitic, consisting of clamped generative hyphae and thick-walled skeletal hyphae.
Lookalike Species
Fomitopsis lilacinogilva
The most important lookalike. Also pinkish to lilac pores, overlapping range in Australia and South America. Separated microscopically: F. lilacinogilva has broader spores (above 2 μm wide); F. feei spores are below 2 μm wide. Spore width measurement is the primary separation character.
Fomitopsis cupreorosea
Occurs in Brazil. Separated from F. feei by ITS molecular sequencing — Soares et al. (2017) demonstrated that Brazilian material previously identified as F. feei resolved as this distinct species. Morphological differences are subtle.
Fomitopsis africana
Tropical Africa. Distinguished by geography and molecular markers. Pink pore surface shared. Not in overlap range unless collector is working from African material.
Species complex caution: The evidence from Soares et al. (2017) raises a strong possibility that material currently called Fomitopsis feei across its pantropical range may represent multiple cryptic species under one name. Collections from South America, Southeast Asia, and Australia may not all be truly conspecific (the same species). Any culture identified by ITS barcode alone — without morphological voucher data — should be considered tentatively identified. Multi-marker sequencing (ITS + TEF1 at minimum) is recommended for confident species assignment.
Where Does Fomitopsis feei (Fee's Polypore) Grow?
Fomitopsis feei (Fee's Polypore) is a pantropical to subtropical species with confirmed records spanning four continents. It colonizes dead and dying hardwood (angiosperm) trees — not conifers. This is an important point that differs from the descriptions of many temperate Fomitopsidaceae members: the well-known North American red-belted conk (Fomitopsis pinicola) prefers conifers, but F. feei grows on broadleaf species.
| Region | Countries with confirmed records | Documented hosts / habitats |
|---|---|---|
| South America | Brazil, Venezuela (type region) | Tropical hardwood timber trees; rainforest |
| Southeast Asia | Philippines, Thailand, Indonesia | Oil palm (Elaeis guineensis); tropical forest margins |
| South Asia | India (Telangana, Kerala) | Tropical hardwood forests; Pakhal forest |
| Australia | Queensland, New South Wales | Eucalyptus and other native hardwoods; wet and dry eucalypt forest |
| Africa | Tropical Africa (records under Rhodofomitopsis) | Angiosperm wood; tropical forest |
Fruiting occurs during tropical wet seasons: November through January in northern-hemisphere tropical regions, and year-round in tropical Queensland with wet-season peaks. No systematic phenological study across the full range has been published.
The ecological role of Fomitopsis feei (Fee's Polypore) as a saprotrophic brown-rot fungus is significant. Brown-rot fungi are globally important decomposers: they break down cellulose and hemicellulose from dead wood through a two-step process involving hydroxyl radical chemistry (called the Fenton reaction, requiring iron and hydrogen peroxide) and carbohydrate-active enzymes. They cannot significantly break down lignin, and the modified lignin residue they leave behind is highly resistant to further decay — which means it contributes to soil organic matter and long-term carbon storage. F. feei is part of this global carbon cycling system in the tropics and subtropics.
The endophyte discovery: In 2008, Rungjindamai et al. isolated Fomitopsis feei as a living endophyte — an organism living inside healthy plant tissue without causing disease — from the leaves of oil palm in Thailand. After 12 months under laboratory conditions, small poroid fruiting bodies appeared on palm petiole tissue. This observation is biologically remarkable: bracket polypores are overwhelmingly known as wood decomposers, not as leaf endophytes. It raises the question of whether F. feei can persist asymptomatically inside a living host before switching to active decay after the host dies — a life-history strategy that, if confirmed across its range, would be unusual for a Fomitopsidaceae member.
Can You Cultivate Fomitopsis feei (Fee's Polypore)?
Fomitopsis feei (Fee's Polypore) has not been brought to reliable fruiting body production under controlled cultivation conditions in any peer-reviewed study. This is a species currently suited to research cultivation — mycelial propagation, agar expansion, grain spawn colonization, and submerged liquid fermentation — rather than harvest cultivation. Understanding what is and is not achievable is essential for anyone working with this culture.
Agar Culture — What the Science Shows
De Leon et al. (2020), working with F. feei collected in the Philippines, conducted a systematic optimization of culture conditions that provides the most detailed published data on this species' agar behavior. Their key findings:
Optimal medium
Coconut Water Gelatin (CWG) produced the best results: maximum radial growth of 83.57 mm in 12 days with very thick mycelial density. Malt Extract Agar (MEA) and Potato Dextrose Agar (PDA) are strong alternatives.
Temperature
28–32°C optimal for mycelial expansion. Growth at 18–24°C is achievable. No growth at 8–10°C. This is a warm-climate species — room temperature in the tropics corresponds to its ideal range.
pH
pH 6.5 produces the highest mycelial density; pH 6.0 is a close second. Growth occurs across pH 5.0–8.0 without statistically significant inhibition — a broad tolerance range.
Atmosphere
Sealed plate conditions (elevated CO₂, reduced oxygen) significantly outperformed unsealed plates. This mirrors the organism's natural environment inside woody substrates and suggests elevated CO₂ promotes vegetative mycelial growth.
Light
Total darkness produced the thickest mycelial growth across all conditions. Any light — regardless of spectrum — reduced density. Keep cultures in the dark during the vegetative phase.
Growth rate
Approximately 6–7 mm/day radial extension on optimal media. Slower than aggressive gilled mushrooms but reasonable for a polypore. Contamination risk from fast-growing competitors like Trichoderma (which can colonize plates in 3–5 days) is elevated.
Grain Spawn
De Leon et al. (2020) also tested three grain substrates for spawn colonization. Cracked corn produced the highest mycelial density and colonized in approximately 16 days — the best-performing substrate. Sorghum seeds performed well as a second choice (~17 days). Rice (palay) seeds produced very thin growth and are not recommended. No fruiting body production was attempted from these grain spawn blocks.
Liquid Culture and Submerged Fermentation
The most productive research context for Fomitopsis feei (Fee's Polypore) liquid culture is submerged fermentation — growing mycelium in a shaken liquid medium. Studies by Hima Bindu & Singara Charya (2017, 2018) and Hima Bindu et al. (2011) established the optimized conditions for both mycelial biomass and exopolysaccharide (EPS, a complex sugar secreted into the growing medium) production.
| Parameter | Optimal for biomass | Optimal for EPS |
|---|---|---|
| Carbon source | Glucose | Malt extract / sugars |
| Nitrogen source | Ammonium sulphate | Malt extract |
| pH | 3–4 | 6–7 |
| Temperature | 30°C | 30°C |
| Agitation | 150 rpm | 150 rpm |
| Peak yield | 6.88 g/L dry mycelium (7 days) | 8.5 g/L EPS (14 days) |
Under shaking conditions, the mycelium forms pellet-like aggregates — a characteristic and healthy submerged growth form. Sweet sorghum extract broth produced 6.6 g/L EPS at 20 days and may be of interest to researchers working with agricultural-waste media.
What Out-Grow's Liquid Culture Contains and How to Use It
Out-Grow's Fomitopsis feei liquid culture is a 12cc syringe of actively growing mycelium suspended in a nutrient-rich liquid medium — a high-density starting point for multiple cultivation and research pathways.
The liquid culture can be used to inoculate agar plates (MEA or PDA work well), transfer mycelium to grain substrate (cracked corn is the documented best choice), or initiate submerged fermentation in a shaken flask for biomass and EPS production. For agar and grain work, maintain temperatures in the 28–32°C range in total darkness during colonization.
Fruiting body production from liquid culture has not been demonstrated in peer-reviewed literature for this species. The realistic applications are research biomass, agar propagation, grain spawn preparation, and experimental substratecolonization. This is an exploration species — one for researchers and enthusiasts interested in contributing to an understudied field.
What Bioactive Compounds Does Fomitopsis feei (Fee's Polypore) Contain?
Fomitopsis feei (Fee's Polypore) has been the subject of several analytical chemistry studies that have identified three categories of biologically active compounds: lanostane triterpenoids (complex fatty-acid-like molecules with a four-ring sterol skeleton), exopolysaccharides, and a suite of oxidative enzymes. All bioactivity data is in vitro — tested in cell or enzyme assays, not in animals or humans.
Lanostane Triterpenoids: Fomitopsins D, E, and F
Isaka et al. (2017), working with fruiting bodies collected in Thailand, isolated three newly described 24-methyl-lanostane triterpenoids from F. feei and named them fomitopsins D, E, and F. The naming continues a series established from other Fomitopsis species.
Fomitopsin D
Antiviral: IC₅₀ = 17 μg/mL against herpes simplex virus type 1 (HSV-1) in a cell-based assay. IC₅₀ is the concentration needed to inhibit 50% of viral activity. 17 μg/mL is considered moderate activity in antiviral screening — scientifically noteworthy, not clinically validated.
Fomitopsin E
Antibacterial: MIC (minimum inhibitory concentration) = 6.25 μg/mL against Bacillus cereus. MIC is the lowest concentration that inhibits visible bacterial growth. This is a meaningful result in a Gram-positive bacterium screening context.
Fomitopsin F
Antibacterial: MIC = 6.25 μg/mL against Bacillus cereus. Also found in Fomitopsis officinalis (Agarikon), where it showed trypanocidal activity — but that data is from a different species and cannot be assumed to apply to F. feei.
Fomitopsins I & J
Further 24-methyl-lanostane triterpenoids isolated in a follow-up study. Antibacterial and cytotoxic activities evaluated; one known compound showed antibacterial activity against Gram-positive bacteria. Full details not available in open-access literature.
Exopolysaccharide (EPS)
Hima Bindu & Singara Charya (2018) characterized the EPS produced by F. feei in submerged fermentation as a proteopolysaccharide — a covalently linked protein-carbohydrate complex rather than a pure beta-glucan. FTIR (infrared spectroscopy) analysis confirmed beta-glucan linkages (β-1,3 and β-1,4), and GC-MS analysis identified glucose as the primary monomer. This structural type differs from the pure beta-glucans studied in most medicinal mushroom research, and its immunological properties remain uncharacterized.
In bioactivity assays, the EPS showed broad-spectrum antibacterial activity (most effective against Proteus vulgaris and Pseudomonas aeruginosa), antifungal activity with greater than 85% spore germination inhibition against most tested fungi (99.5% inhibition of Curvularia lunata), and antioxidant activity reaching 93.5% radical scavenging in one assay. Enzyme inhibition (5-lipoxygenase, alpha-glucosidase, tyrosinase) was moderate. All results are in vitro.
Enzymatic Activities
Culture filtrates of F. feei grown on agricultural waste-based broths produced measurable lignin peroxidase (302 U/mL in rice bran broth), laccase (142 U/mL in whey broth), and manganese peroxidase (40 U/mL). A counterintuitive finding: when the filtrate was tested for dye decolorization, the responsible enzyme was not laccase or lignin peroxidase (despite their high activities) but triphenylmethane reductase — an enzyme that decolorized basic fuchsin at 98% and bromophenol blue at 96.8%. This dissociation between enzyme abundance and functional activity is unusual and may have implications for bioremediation applications.
Is Fomitopsis feei (Fee's Polypore) Safe?
Fomitopsis feei (Fee's Polypore) is not edible — its woody texture makes it physically impossible to consume as food, and there is no documented culinary tradition involving this species anywhere in its range. The relevant safety questions concern contact and handling of cultures, and the interpretation of preliminary toxicological screening data.
De Leon et al. (2020) assessed the toxicological potential of an ethanol extract from F. feei using zebrafish embryo and brine shrimp assays — standard preliminary screening tools. In the zebrafish assay, the LC₅₀ (the concentration that killed 50% of embryos) was 534.676 ppm, placing it in the "mildly toxic" category on standard toxicological scales. Teratogenic effects (developmental abnormalities including growth retardation, malformed tails, and pericardial edema) were observed at concentrations of 750 ppm and above; 100% mortality occurred at 1,000 ppm.
Important context: These results come from concentrated ethanol extract applied directly to zebrafish embryos — a preliminary screening method, not a predictor of human toxicity at normal exposure levels. No human toxicity cases have been reported in any published literature. No animal model oral toxicity study (the type needed to establish meaningful safety parameters) exists for F. feei. The appropriate characterization is: unknown safety profile; no human consumption data; mildly toxic ethanol extract in embryo screening. Do not handle cultures without standard mycological precautions.
No drug interactions are documented. No clinical safety assessments in humans have been conducted. F. feei is not sold as a supplement ingredient in any major market.
What Makes Fomitopsis feei (Fee's Polypore) Scientifically Remarkable?
1. An Endophytic Polypore
The 2008 isolation of F. feei from healthy oil palm leaves in Thailand is one of the more unusual ecological records in the polypore literature. Bracket polypores are almost universally known as saprotrophs or tree pathogens — not as leaf endophytes. The possibility that F. feei maintains a latent endophytic phase inside living plant tissue before transitioning to saprotrophic wood decay after host death represents a life-history strategy that, if confirmed across its range, would be genuinely unusual for a Fomitopsidaceae member and opens questions about how long it can persist asymptomatically inside a living host.
2. A Triphenylmethane Reductase Surprise
Fomitopsis feei cultures produce high levels of laccase and lignin peroxidase — enzymes routinely targeted in industrial dye decolorization research. But when the culture filtrate was tested for actual dye decolorization, the enzyme responsible was triphenylmethane reductase, not the high-activity oxidoreductases. The cultures with the highest laccase activity were not the best dye decolorizers. This counterintuitive dissociation means conventional assumptions about which enzymes drive dye degradation cannot be applied without species-specific testing, and suggests F. feei may have a distinct bioremediation profile worth investigating independently.
3. Novel Antiviral Chemistry in a Structurally Unusual Compound Class
The fomitopsins are 24-methyl-lanostane triterpenoids — a structural class not commonly found in confirmed antivirals. Fomitopsin D's IC₅₀ of 17 μg/mL against HSV-1 is moderate-to-weak by clinical standards, but the mechanism of action (how it inhibits the virus) is completely unknown. Whether it disrupts the viral envelope, interferes with DNA replication, or blocks host-cell entry are all open questions. Establishing the mechanism is a prerequisite for assessing whether this compound class has pharmaceutical development potential.
4. A Case Study in Taxonomic Philosophy
The seven-year life span of Rhodofomitopsis as a genus (2016–2024) and its return to Fomitopsis in 2024 illustrates a live debate in mycological systematics: "splitters" who argue that molecular distinctiveness justifies creating many small genera versus "lumpers" who argue that stability and practical utility favor broadly defined genera. Spirin et al. (2024) explicitly argued for the lumper position — noting that producing dozens of monotypic or near-monotypic genera from Fomitopsidaceae created a classification that was difficult to use and prone to further revision. The Fomitopsis feei case is a clean example of this tension playing out in real time across international databases that still haven't synchronized their records.
5. A Likely Species Complex
The work of Soares et al. (2017) in Brazil — demonstrating that material previously identified as F. feei actually resolved as the distinct species F. cupreorosea on ITS sequencing — raises a significant open question: is Fomitopsis feei as currently circumscribed actually one species, or a cluster of cryptic species sharing similar morphology across a pantropical distribution? Population genomic sampling across South America, Southeast Asia, India, and Australia is urgently needed before any conclusion about biological properties can be generalized across the full range. The compounds isolated from Thai material may not be representative of Brazilian or Indian material if those populations are genuinely distinct species.
Frequently Asked Questions About Fomitopsis feei (Fee's Polypore)
What does "Fee's Polypore" mean, and is it the real common name?
"Fee's Polypore" honors Antoine Laurent Apollinaire Fée (1789–1874), the French botanist and pharmacist whose name appears in the species epithet feei. However, this common name does not appear in any peer-reviewed literature, field guide, or mycological checklist — it is best understood as a vendor convenience name used by Out-Grow and a small number of informal sources. The scientific name Fomitopsis feei is the primary form used in all academic and database records and should be the primary search term when researching this species.
Is Fomitopsis feei the same as Rhodofomitopsis feei?
Yes — they refer to the same organism at different points in its taxonomic history. From 2016 to 2024, the species was placed in a new genus, Rhodofomitopsis, based on molecular phylogenetic evidence. In 2024, Spirin et al. published a comprehensive revision of Fomitopsidaceae that synonymized Rhodofomitopsis and approximately twenty other genera back under a broadly defined Fomitopsis. The accepted name is now Fomitopsis feei (Fr.) Kreisel, but many databases (including GBIF and NCBI) still carry the old name as of early 2026.
Where does Fomitopsis feei actually grow? I've seen it described as a North American conifer species.
That description is incorrect and conflates F. feei with other Fomitopsidaceae members. Fomitopsis feei is a pantropical to subtropical species — confirmed from Venezuela and Brazil, the Philippines, Thailand, Indonesia, India, and Australia. It grows exclusively on hardwood (angiosperm) trees, not conifers. The temperate conifer-associated polypore often confused with it by casual description is Fomitopsis pinicola (the red-belted conk), a distinct species with a very different range and host association.
Can Fomitopsis feei be cultivated to produce fruiting bodies?
No published peer-reviewed protocol exists for producing fruiting bodies under controlled conditions. Mycelial growth on agar, grain spawn colonization, and submerged liquid fermentation have all been documented and optimized. The only observation of fruiting under laboratory conditions comes from Rungjindamai et al. (2008), who noted small basidiocarps appearing on oil palm petiole tissue after 12 months — a timeline that reflects the slow basidiocarp development typical of perennial polypores. Liquid culture from Out-Grow is best used for research biomass, agar expansion, grain spawn inoculation, and experimental substrate work.
What are the antiviral and antibacterial compounds in Fomitopsis feei?
Isaka et al. (2017) isolated three novel lanostane triterpenoids — fomitopsins D, E, and F — from fruiting bodies collected in Thailand. Fomitopsin D showed antiviral activity against herpes simplex virus type 1 (HSV-1) with an IC₅₀ of 17 μg/mL in a cell-based assay. Fomitopsins E and F both showed antibacterial activity against Bacillus cereus with a minimum inhibitory concentration (MIC) of 6.25 μg/mL. All results are in vitro — laboratory assays — with no animal or human data. The mechanism of action for all three compounds is unknown.
How do I identify Fomitopsis feei in the field?
Look for a sessile (stalk-less) bracket polypore on dead or dying hardwood in tropical to subtropical regions. Key characters: pink to pale rose pore surface (6–8 pores per mm), pinkish-brown to buff cap surface with concentrically zoned ridges, rose-brown cross-sectioned flesh, and a cherry-red to black KOH reaction on the flesh. Microscopic confirmation — specifically the narrow, spindle-shaped spores under 2 μm wide — is needed to separate it from Fomitopsis lilacinogilva, its closest lookalike. In Australia especially, consult the Queensland Fungal Record and the NatureMapr Rhodofomitopsis lilacinogilva complex notes.
Also available as a culture plate from Out-Grow.
Fomitopsis feei (Fee's Polypore) Culture Plate