Berkeley's Polypore (Bondarzewia berkeleyi)
Berkeley's Polypore (Bondarzewia berkeleyi)
Berkeley's Polypore (Bondarzewia berkeleyi) is a large edible fungus native to the oak forests of eastern North America, producing rosettes of cream-colored fan-shaped caps at hardwood tree bases. A single fruiting body can weigh over 20 pounds, making it one of the largest mushrooms in its range. Young specimens are considered a choice edible with a mild flavor and firm texture that holds up well to cooking.
Berkeley's Polypore (Bondarzewia berkeleyi) is one of the largest and most striking fungi in eastern North America — a white-rot wood-decay fungus capable of producing fruiting bodies exceeding two feet across and 35 pounds in weight, emerging each summer in overlapping rosettes from the root flares of oaks, maples, and chestnuts. It is edible when young, with a mild flavor that absorbs seasonings readily; it becomes tough and bitter within weeks. Despite its polypore appearance — pored underside, fan-shaped caps, tough fibrous flesh — molecular phylogenetics places Berkeley's Polypore (Bondarzewia berkeleyi) firmly among the russulas and milky caps, making it one of mycology's most instructive examples of convergent evolution.
Interested in this species? Out-Grow carries a liquid culture.
Berkeley's Polypore (Bondarzewia berkeleyi) Liquid CultureWhat Is Berkeley's Polypore (Bondarzewia berkeleyi)?
Berkeley's Polypore (Bondarzewia berkeleyi) belongs to the family Bondarzewiaceae within the order Russulales — a phylogenetic placement that surprises nearly everyone who encounters it. Russulales is the order that contains Russula (the brightly colored brittlegills) and Lactarius (the milky caps). Berkeley's Polypore (Bondarzewia berkeleyi) looks nothing like either. It produces a massive, tiered, pore-bearing rosette from the base of oak trees — the classic silhouette of a polypore. But molecular analysis first demonstrated in 1995 (Hibbett & Donoghue) that Bondarzewia is more closely related to Russula than to any true polypore in the order Polyporales. The polypore body plan, it turns out, evolved independently multiple times across the fungal tree of life.
The genus Bondarzewia is named for Apollinaris Semenovich Bondartsev (1877–1968), a Russian mycologist who collaborated with Rolf Singer and made major contributions to wood-decay fungus taxonomy. The species epithet berkeleyi honors Miles Joseph Berkeley (1803–1889), often called the father of British mycology. When Elias Magnus Fries — the towering figure of nineteenth-century mycology — first described this species from a North Carolina herbarium collection, he is said to have called it "the most noble of all the polypores known to me." The result is a double eponym: a species named after one legendary mycologist, in a genus named after another.
Berkeley's Polypore (Bondarzewia berkeleyi) is not actually a polypore. Despite its pored underside, tough fibrous flesh, and rosette habit at tree bases — all hallmarks of polypores — it belongs in Russulales, phylogenetically closer to the delicate brittlegill Russula than to any true polypore. The microscopic giveaway is its amyloid spores (which turn blue-black in Melzer's reagent, a standard chemical test), a trait that betrays its russula lineage even when the macroscopic features point the other direction. This makes it a textbook case in mycology education of how morphology-based classification can mislead.
Berkeley's Polypore (Bondarzewia berkeleyi) is a white rot fungus — it breaks down both lignin (the structural polymer that gives wood rigidity) and cellulose (the main carbohydrate component of wood), bleaching the wood and creating a soft, stringy decay. It operates primarily as a parasite on living hardwoods, entering through root contacts or wounds and colonizing the heartwood. After the host tree dies, it persists saprotrophically on the resulting deadwood. Because its nutritional strategy does not require a living tree root partner, Berkeley's Polypore (Bondarzewia berkeleyi) does not face the fundamental biological barrier to cultivation that mycorrhizal fungi like chanterelles and matsutake do. The challenge of cultivating it is practical, not theoretical.
One of the most unusual structural features of Berkeley's Polypore (Bondarzewia berkeleyi) is that its fruiting bodies emerge from a belowground sclerotium — a compact, dormant mass of mycelium used for long-term nutrient storage. Sclerotia are found in relatively few macrofungi and represent some of the most elaborate fungal structures known. This underground anchor allows a single Berkeley's Polypore (Bondarzewia berkeleyi) mycelium to refruit from the same location annually for years.
How Is Berkeley's Polypore (Bondarzewia berkeleyi) Classified?
| Rank | Name |
|---|---|
| Kingdom | Fungi |
| Phylum | Basidiomycota |
| Class | Agaricomycetes |
| Order | Russulales |
| Family | Bondarzewiaceae |
| Genus | Bondarzewia |
| Species | Bondarzewia berkeleyi (Fr.) Bondartsev & Singer |
Wikipedia and several popular sources list the family as Russulaceae. This is incorrect. The accepted family, per GBIF, MycoBank, Index Fungorum, and the primary phylogenetic literature, is Bondarzewiaceae Kotlaba & Pouzar (1957). The Russulaceae attribution is a legacy error that propagated from earlier molecular work. The order Russulales is correct for both, but the family is Bondarzewiaceae.
The accepted name, Bondarzewia berkeleyi (Fr.) Bondartsev & Singer, was published in Annales Mycologici 39(1): 47 in 1941. The basionym — the original name on which the current name is formally based — is Polyporus berkeleyi Fr. (1851), reflecting the species' original placement in the broad, catch-all polypore genus before molecular methods revealed its true affinities. Several synonyms exist, including Polyporus eurocephalus Berk. & Broome (1875, an independent description of the same organism) and Grifola berkeleyi (Fr.) Murrill (1904, a transfer to another morphological genus), but the Bondartsev & Singer combination has been the accepted name for over 80 years.
Within the genus Bondarzewia — which currently contains 11 accepted species — Berkeley's Polypore (Bondarzewia berkeleyi) occupies the most basal, phylogenetically isolated position. A landmark 2016 multi-locus molecular analysis (Song et al., Scientific Reports 6:34568) found that B. berkeleyi does not fall into any of the three major clades that contain the other Holarctic Bondarzewia species. Its estimated divergence from its closest relatives was approximately 8.5 million years ago (Miocene), earlier than any of its congeners. Song et al. describe this isolation as possibly reflecting either incomplete species sampling in Central America or a "relic" status — Berkeley's Polypore (Bondarzewia berkeleyi) may be a survivor of a lineage that was once more widespread but largely lost.
| Database | ID / Accession |
|---|---|
| GBIF Backbone Key | 2552027 |
| MycoBank Family ID | 58831 (Bondarzewiaceae) |
| Key GenBank ITS | KJ583202 (Dai 12759) |
| Key GenBank nLSU | KJ583216 (Dai 12759) |
How Do You Identify Berkeley's Polypore (Bondarzewia berkeleyi)?
Berkeley's Polypore (Bondarzewia berkeleyi) is visually unmistakable at maturity — a compound, rosette-shaped polypore 20 to 60 or more centimeters across, consisting of one to several spiraling, fan-shaped or kidney-shaped caps arising from a single gnarled, stem-like central structure. Individual caps range from 6 to 25 centimeters across. Exceptional specimens have been documented exceeding two feet wide and 35 pounds. The cap surface is dry, velvety to leathery, and never scaly. Color progresses from white in young specimens to cream and dull yellowish at maturity, eventually reaching tan to light brown in older or desiccated material. The flesh is white, thick (up to 3 cm), firm, and fibrous — corky in older specimens — and does not discolor or bruise when cut.
The pore surface is white to off-white, running decurrent (extending down onto the stem face), with circular pores at 1–2 per mm when young, becoming more angular and wider with age. The stem is 4–10 cm long, 3–5 cm wide, whitish to dull yellowish, tough, and branched from a buried, gnarled base that connects to the belowground sclerotium. Taste is mild in young specimens and becomes distinctly bitter with age and size. Odor is not distinctive when young but becomes rank and unpleasant in older specimens.
Microscopically, the strongly amyloid spores — globose to subglobose, 7–9 × 6–8 µm, with densely packed, blunt-tipped spines 1–2 µm long — are the tell-tale russula-lineage character. The hyphal system is dimitic (two types of hyphae: thick-walled skeletal hyphae and thin-walled generative hyphae), and clamp connections are absent — a combination that is unusual in the Russulales context and reflects this species' unusual position within the order.
Young Berkeley's Polypore (Bondarzewia berkeleyi) does not look like a polypore. Early specimens emerge as compact, lobed, finger-like or bulbous masses — pallid with hues of tan, pink, and orange — that are radically different from the mature rosette form. This stage confuses experienced foragers and is sometimes not identifiable to species without observing the specimen over time or knowing the host substrate and location.
Lookalike Species
The single most reliable field test: Meripilus sumstinei stains dramatically black when handled or damaged. Berkeley's Polypore (Bondarzewia berkeleyi) does NOT stain black. Always perform this test. Both grow at the base of hardwood trees; both are edible. The blackening test resolves the confusion immediately.
Hen of the Woods has darker gray-brown caps, smaller and thinner individual fronds, and many more overlapping fronds from a branched base. Berkeley's Polypore (Bondarzewia berkeleyi) has far larger, fewer, thicker, and paler caps. Both grow at oak bases in fall — confusion is common in beginners but straightforward for experienced foragers. Both are excellent edibles.
White-Pored Chicken of the Woods has distinctive orange and cream hues, a very different texture, and lacks the large fan-shaped rosette habit. Color alone distinguishes it easily from the cream-to-tan Berkeley's Polypore (Bondarzewia berkeleyi).
The western North American equivalent of Berkeley's Polypore. Separated as a distinct species by molecular analysis (Chen et al., 2016). Distinguished by its purplish-brown to gray-brown cap (vs. cream/tan), association with conifers in western North America, and typically fewer caps from one stem. Any Bondarzewia found on conifers west of the Rockies is B. occidentalis, not B. berkeleyi.
Where Does Berkeley's Polypore (Bondarzewia berkeleyi) Grow?
Berkeley's Polypore (Bondarzewia berkeleyi) is native exclusively to eastern North America — it is the only Bondarzewia species on that continent east of the Great Plains. Its range extends through the eastern United States and into Mexico (occasional reports), with the species considered common in the oak forests of the Southeast, Mid-Atlantic, and Midwest. It is rare but present in the Great Lakes region of Minnesota and Wisconsin.
Multiple popular sources, including Wikipedia, claim Berkeley's Polypore (Bondarzewia berkeleyi) occurs in Africa, Asia, and Europe. Per the molecular phylogeny of Song et al. (2016) and Chen et al. (2016), these Old World records are now attributed to other Bondarzewia species — B. mesenterica, B. dickinsii, and others. Bondarzewia berkeleyi sensu stricto is an eastern North American species.
Berkeley's Polypore (Bondarzewia berkeleyi) fruits from July through October, with peak fruiting typically in August and September. Fruiting bodies are annual — they appear each year, not as perennial structures. They emerge at or near the base of living or recently dead hardwood trees, most often directly over the root flare, but sometimes several feet from the trunk if emerging from lateral roots. Primary hosts are oaks (Quercus spp., especially white oak, red oak, and black oak), with secondary hosts including chestnut (Castanea), maple (Acer), and cherry (Prunus). Once a tree is infected, the fungus can return year after year from the same belowground sclerotium.
An important ecological note for arborists and tree owners: trees infected with Berkeley's Polypore (Bondarzewia berkeleyi) often appear canopy-healthy while structurally compromised at the butt. The fungus colonizes heartwood and root tissue while leaving the sapwood largely intact, so the crown may show no dieback even as the structural integrity of the root system is significantly reduced. Fruiting bodies at the base of an urban oak are a reliable indicator of internal white rot and potential structural failure risk.
Can You Cultivate Berkeley's Polypore (Bondarzewia berkeleyi)?
Berkeley's Polypore (Bondarzewia berkeleyi) occupies an unusual middle ground in cultivation: its mycelium propagates reliably in liquid culture and on agar, and its biology is fundamentally compatible with lignocellulosic substrate — but reproducible fruiting body production under controlled conditions has not been documented in peer-reviewed literature as of early 2026. This is an honest assessment, and it is worth understanding why.
Unlike obligate mycorrhizal fungi (chanterelles, matsutake, truffles) that require a living tree root system to complete their life cycle, Berkeley's Polypore (Bondarzewia berkeleyi) is a white rot saprotroph and parasite that derives all its nutrition from decomposing wood. This means the biological barrier to cultivation does not exist. The same nutritional strategy used by cultivable polypores — Ganoderma, Trametes, Laetiporus — applies here. The challenge is practical: fruiting triggers, substrate optimization, and the species' tendency to grow slowly have not been systematically studied.
Substrate Preparation
Use sterilized hardwood sawdust — oak, maple, or mixed hardwood — to mirror the species' natural host preference. A substrate block of at least 1,500 g dry sawdust is recommended; larger block size appears beneficial for this species. Supplementation with wheat bran or oat bran (10–20% by weight) may support colonization but increases contamination risk and should be used with strict sterilization protocol. Sterilize in polypropylene bags at 121°C for 90–120 minutes.
Inoculation & Spawn Run
Inoculate cooled bags with Berkeley's Polypore (Bondarzewia berkeleyi) liquid culture. Colonize at 20–24°C (68–75°F) — the consistent range reported across independent vendor data. Expect slower colonization than common edible polypores; practitioners report growth notably slower than oyster or shiitake strains. Standard contamination risks apply: Trichoderma, Penicillium, and Bacillus spp. are the primary competitors on hardwood-based substrates, and this species' slower growth rate increases the window during which contaminants can establish.
Fruiting Attempt
Once colonization is complete, initiate fruiting conditions: 18–24°C (65–75°F), approximately 90% relative humidity, and increased fresh air exchange (FAE — the cycling of fresh air to reduce CO₂ buildup). These parameters follow general polypore fruiting principles; no species-specific fruiting trigger has been identified for Berkeley's Polypore (Bondarzewia berkeleyi) in published research. Fruiting under artificial conditions is technically demanding for this species, and hobbyist cultivators should approach it as an experimental project rather than a reliable crop.
Alternative: Agar & Research Work
For cultivators primarily interested in culture work, Berkeley's Polypore (Bondarzewia berkeleyi) liquid culture transfers readily to PDA (potato dextrose agar) or MEA (malt extract agar) plates for culture maintenance, strain archiving, and contamination assessment. The liquid culture also serves as inoculum for sterilized grain spawn production, which can then be used for substrate inoculation or longer-term experimental work.
How to Use the Berkeley's Polypore (Bondarzewia berkeleyi) Liquid Culture
Out-Grow's liquid culture contains active Berkeley's Polypore (Bondarzewia berkeleyi) mycelium in sterile nutrient solution. It can be used to inoculate sterilized grain spawn (rye berries, wheat berries, or corn) for subsequent bulk substrate inoculation, injected directly into sterilized hardwood sawdust bags for colonization and attempted fruiting, or used to inoculate PDA or MEA agar plates for culture maintenance and strain archiving.
The liquid culture is also viable for mycelial biomass production in submerged fermentation — a research pathway relevant to future biochemical characterization of this species. Multiple commercial vendors confirm LC stability of up to 12 months refrigerated at 4°C. As with all slower-growing polypore species, strict aseptic technique during inoculation is especially important. Fruiting under artificial conditions is technically demanding and should be approached as experimental cultivation rather than routine production.
What Bioactive Compounds Does Berkeley's Polypore (Bondarzewia berkeleyi) Contain?
Berkeley's Polypore (Bondarzewia berkeleyi) is one of the least chemically characterized polypores of its size and prominence. As a 2024 ACS Omega study on the closely related Bondarzewia mesenterica explicitly stated, the genus Bondarzewia as a whole is "understudied concerning the chemistry of its secondary metabolites." All chemistry data for Berkeley's Polypore (Bondarzewia berkeleyi) specifically comes from two Chinese studies from the mid-2000s and one 2022 Indian protein study. Each is presented below with honest evidence quality assessment.
A meroterpenoid (compound combining terpenoid and aromatic building blocks) with CAS 247132-16-7, molecular formula C₁₂H₁₂O₄. Isolated from fruiting body material. Described as "weakly cytotoxic" (meaning it inhibits cell growth at high concentrations) in a 2024 review, but no specific IC₅₀ value (the concentration needed to inhibit 50% of target cells) from B. berkeleyi specifically has been published. Montadial is shared with the related European species B. mesenterica.
A new dihydrobenzofuran (an oxygen-containing aromatic ring compound) isolated from submerged liquid culture of B. berkeleyi (Shao et al., Plant Diversity 2007). Notably, the 2024 ACS Omega review flagged that "no proof was given as to whether the study culture was authentic" — the culture identity was unverified. No biological activity was reported for these compounds. These are of particular interest to LC cultivators, as they were derived from culture broth rather than fruiting body.
A protein fraction (~56 kDa by SDS-PAGE, a standard gel electrophoresis technique for sizing proteins) isolated from Indian fruiting bodies showed antibacterial activity against Proteus vulgaris (MIC 0.4 µg/mL) and in vitro cytotoxicity against A549 lung cancer cells (IC₅₀ 19.37 µg/mL). Results are preliminary, published in a lower-impact journal, and have not been independently replicated. The protein is unsequenced.
Vibralactones Z5 and Z6 (novel lactone derivatives) and sesquiterpenoid aldehydes including isovelleral and erinacine P were characterized from B. mesenterica (European sister species) in 2024. The sesquiterpenoids showed IC₅₀ values of 2.8–14.2 µM against cancer cell lines and MIC values of 8.3–16.6 µg/mL against fungi — in vitro only. Montadial is shared with B. berkeleyi; the others are not confirmed for this species.
β-Glucans (immunomodulatory polysaccharides found in all basidiomycete cell walls) are almost certainly present, as they are universal in white rot Basidiomycota. They have not been isolated, quantified, or characterized from Berkeley's Polypore (Bondarzewia berkeleyi) specifically. No polysaccharide content data exists for this species.
The bitter taste that develops in older Berkeley's Polypore (Bondarzewia berkeleyi) specimens likely reflects the accumulation of terpenoid aldehydes or similar secondary metabolites — consistent with the montadial and isovelleral chemistry documented in the genus. The rapid onset of bitterness (days to weeks after emergence) has not been chemically characterized in this species specifically, and whether the bitter compounds at culinary concentrations pose any safety concern is unknown.
Is Berkeley's Polypore (Bondarzewia berkeleyi) Safe to Eat?
Berkeley's Polypore (Bondarzewia berkeleyi) is considered edible when young. David Arora's Mushrooms Demystified and the Audubon Society Field Guide both list it as edible. No toxic compounds have been isolated from any Bondarzewia species, and no documented cases of poisoning attributable to Berkeley's Polypore (Bondarzewia berkeleyi) appear in the mycological or toxicological literature. One field guide — the Falcon Guide — controversially lists it as "inedible," a designation that almost certainly refers to the toughness and bitterness of older specimens rather than toxicity.
Edibility is strictly age-dependent and represents one of the narrowest culinary windows of any edible polypore. Young, white-margined specimens with soft flesh are mild and edible; they absorb flavors and seasonings readily and are described by experienced forager-chefs as similar in character to a mild chicken of the woods. Within days to weeks, the same individual becomes tough, corky, and distinctly bitter — essentially inedible from a texture and flavor standpoint, regardless of preparation method. Harvest timing is the most critical factor in the culinary experience.
Berkeley's Polypore (Bondarzewia berkeleyi) should not be consumed raw, consistent with standard polypore handling. Cooking degrades potential irritant compounds. The mild flavor of young specimens lends itself to dishes where the mushroom absorbs other flavors — stocks, braises, and preparations that compensate for the relatively neutral baseline taste. Older specimens should not be eaten regardless of preparation.
No known drug interactions have been documented. The standard caveat applies: anyone with known fungal or mold allergies should exercise appropriate caution. The absence of documented toxicity cases reflects both the genuine low toxicity of young specimens and the species' moderate consumption rate — it is not a widely traded commercial edible, which limits exposure-event data relative to species like shiitake or oyster mushrooms. No formal toxicological evaluation of Berkeley's Polypore (Bondarzewia berkeleyi) has been conducted.
What Makes Berkeley's Polypore (Bondarzewia berkeleyi) Remarkable?
A Polypore That Isn't — Convergent Evolution
Berkeley's Polypore (Bondarzewia berkeleyi) is phylogenetically a russula relative that independently evolved the polypore body plan. Pores, tough flesh, and a rosette habit at tree bases all evolved separately in Polyporales and in Russulales. The microscopic giveaway — amyloid globose spores — betrays its true lineage. It is one of mycology's most-cited examples of morphological convergence misleading classification.
Basal Relict of Its Genus
Berkeley's Polypore (Bondarzewia berkeleyi) diverged from all other Holarctic Bondarzewia approximately 8.5 million years ago and does not fall into any of the three major clades that contain its congeners. Song et al. (2016) speculate it may be a survivor of a lineage once more widespread in eastern North America — a phylogenetic relict whose relatives were largely lost over geological time.
The Underground Sclerotium
Berkeley's Polypore (Bondarzewia berkeleyi) fruits from a belowground sclerotium — a compact, dormant mass of mycelium used for long-term nutrient storage. Sclerotia are found in relatively few macrofungi and are among the most elaborate fungal structures known. This underground anchor allows the same individual to refruit annually for years from the same location. The conditions that trigger sclerotium formation vs. vegetative growth vs. fruiting in culture are entirely unstudied.
The First Mycoviruses in the Genus
In 2020, Vainio & Sutela characterized two novel mycoviruses co-infecting a single Berkeley's Polypore (Bondarzewia berkeleyi) isolate: BbPV1 (a dsRNA partitivirus) and BbNSRV1 (a negative-sense RNA virus related to Mymonaviridae — only the second such virus described from a basidiomycete). These were the first mycoviruses documented in any Bondarzewia species. Whether they affect growth rate, fruiting, or bioactive compound production is entirely unknown.
The Bitterness Race
Young Berkeley's Polypore (Bondarzewia berkeleyi) is mild and edible; within days to weeks, the same fruiting body becomes bitter and tough enough to be inedible. The chemical basis for this rapid transformation — likely terpenoid or aldehyde accumulation consistent with the montadial chemistry of the genus — is completely uncharacterized for this species specifically. The narrowness of the culinary window is unusual even among polypores.
Stealth Pathogen in Urban Landscapes
Berkeley's Polypore (Bondarzewia berkeleyi) colonizes heartwood and root tissue while leaving sapwood largely intact — so infected urban trees often look crown-healthy while structurally compromised at the butt. Fruiting bodies at an urban oak's base are a significant structural failure indicator. This "stealth pathology" gives it an ecological dual role: nutrient cycler in forest ecosystems and structural hazard creator in managed landscapes.
Frequently Asked Questions About Berkeley's Polypore (Bondarzewia berkeleyi)
Is Berkeley's Polypore (Bondarzewia berkeleyi) edible?
Yes — when young. Berkeley's Polypore (Bondarzewia berkeleyi) is listed as edible in Arora's Mushrooms Demystified and the Audubon Society Field Guide. Young, white-margined specimens with soft flesh are mild, with a flavor that absorbs seasonings readily. However, edibility is strictly age-dependent: the same fruiting body becomes tough, corky, and distinctly bitter within days to weeks of emergence. Older specimens are not poisonous, but they are essentially inedible due to texture and bitterness. Harvest only young, fresh specimens with white growing margins.
Where does Berkeley's Polypore (Bondarzewia berkeleyi) grow?
Berkeley's Polypore (Bondarzewia berkeleyi) grows exclusively in eastern North America, from the Southeast and Mid-Atlantic through the Midwest and into New England, with occasional records in Mexico. It fruits at the base of living or recently dead hardwood trees — primarily oaks — from July through October, with peak fruiting in August and September. It can emerge several feet from the trunk if its mycelium is tracking a lateral root. Despite claims in several popular sources, it does not occur in Europe, Africa, or Asia; those records refer to other Bondarzewia species.
How do you identify Berkeley's Polypore (Bondarzewia berkeleyi)?
Look for a massive (20–60+ cm), cream-to-tan rosette of overlapping fan-shaped caps at the base of an oak tree in summer or fall, in eastern North America. The pore surface is white and runs down onto the stem. The flesh is white, does not bruise, and the spore print is white. The single most important field test: Berkeley's Polypore (Bondarzewia berkeleyi) does NOT stain black when handled or cut — this immediately distinguishes it from the similar black-staining polypore (Meripilus sumstinei). Be aware that young specimens look nothing like mature ones — early buttons are lobed, pale, and finger-like.
Is Berkeley's Polypore (Bondarzewia berkeleyi) actually a polypore?
Despite its appearance, no — not in the phylogenetic sense. Berkeley's Polypore (Bondarzewia berkeleyi) belongs to the order Russulales, making it a relative of Russula (brittlegills) and Lactarius (milky caps) rather than true polypores in the order Polyporales. The polypore body plan evolved independently in Russulales — a phenomenon called convergent evolution. The microscopic giveaway is the strongly amyloid globose spores (they stain blue-black in Melzer's reagent), a russula-lineage trait. Its correct family is Bondarzewiaceae, not Russulaceae as some sources claim.
Can you cultivate Berkeley's Polypore (Bondarzewia berkeleyi)?
The mycelium propagates reliably in liquid culture and on agar, and the species' biology — a white rot saprotroph — is fundamentally compatible with lignocellulosic substrate cultivation. However, reproducible fruiting body production under controlled conditions has not been documented in peer-reviewed literature as of early 2026. Multiple vendors offer liquid culture, confirming reliable mycelial propagation. Fruiting attempts on sterilized hardwood sawdust are the recommended experimental approach, but should be treated as exploratory research rather than reliable crop production. This is one of the more challenging cultivation projects in amateur mycology.
How is Berkeley's Polypore (Bondarzewia berkeleyi) liquid culture used?
Out-Grow's Berkeley's Polypore (Bondarzewia berkeleyi) liquid culture can be used to inoculate sterilized grain spawn (rye berries, wheat, or corn) for subsequent bulk substrate work, injected directly into sterilized hardwood sawdust bags for colonization and fruiting attempts, or used to inoculate PDA or MEA agar plates for culture maintenance and archiving. The liquid culture is also valuable for mycelial biomass production and as research culture material. Store refrigerated at 4°C for up to 12 months. Aseptic technique is essential given the species' slower growth rate relative to common edible fungi.
Also available as a culture plate from Out-Grow.
Berkeley's Polypore (Bondarzewia berkeleyi) Culture Plate