Tiger Sawgill (Lentinus tigrinus)
Tiger Sawgill (Lentinus tigrinus)
Tiger Sawgill (Lentinus tigrinus) is a wood-decaying mushroom native to riparian hardwood forests across Europe, North America, and Asia, recognized by its dark tiger-stripe scales and saw-toothed gills. gills. It is phylogenetically a polypore—a close relative of bracket fungi—that independently evolved gills, and it is the only species known in Polyporales with a genetically controlled dual fruiting body: some individuals produce normal open gills, while others produce sealed, gastroid forms where spores develop inside. Peer-reviewed cultivation protocols exist from six countries, and biological efficiency of up to 62% has been documented on supplemented willow sawdust.
Lentinus tigrinus (Bull.) Fr. — Family: Polyporaceae — Order: Polyporales — Index Fungorum / MycoBank: 164542
Tiger Sawgill (Lentinus tigrinus) is the most widely distributed species in the genus Lentinus, documented from 17 countries across four continents. Despite its global range and 3,000+ iNaturalist observations, it remains genuinely underexplored in cultivation and chemistry compared with commercial mushrooms. Published research has confirmed edibility, documented biological efficiency up to 62% on supplemented hardwood sawdust, characterized a laccase enzyme with unusual in vitro properties, and sequenced full genomes for both its agaricoid and its unique sealed, gastroid fruiting form. It is also currently the subject of an unresolved taxonomic split that may soon separate North American and Eurasian populations into distinct species—a situation with immediate practical implications for cultivators and researchers working with this organism.
What Is Tiger Sawgill (Lentinus tigrinus)?
Tiger Sawgill (Lentinus tigrinus) is a white-rot saprotrophic fungus—meaning it enzymatically degrades both lignin and cellulose in dead wood, with a preference for lignin, leaving pale cellulose residue behind. It belongs to Polyporaceae (Polyporales), the same family as centrally stipitate polypores such as Polyporus squamosus (Dryad's Saddle). Despite having gills rather than pores, molecular phylogenetics has unambiguously placed it within this polypore family, and microscopic structures called hyphal pegs on the gill surface confirm this polypore heritage.
The common name "Tiger Sawgill" is taxonomically precise: it captures both the tiger-stripe pattern of dark radial scales over a pale cap, and the distinctive saw-toothed, serrated gill edges—the "sawgill" character visible with a hand lens that identifies all members of Lentinus sensu stricto. The name is used consistently across MushroomExpert, iNaturalist, First Nature, the British Mycological Society, and the Hibbett Lab at Clark University.
Tiger Sawgill (Lentinus tigrinus) is classified as edible and has been consumed in the Philippines, parts of tropical Asia, and experimentally across multiple cultivation studies. Its fruiting bodies contain 25.9% crude protein (dry weight pileus), and published cultivation work has delivered genuine yields on hardwood and straw-based substrates. The species' primary commercial interest is as a cultivated functional food mushroom and as a source of ligninolytic enzymes for industrial biotechnology—including laccase enzymes used in pulp biobleaching, phenol biodegradation, and agricultural bioconversion.
Interested in this species? Out-Grow carries a liquid culture.
Tiger Sawgill (Lentinus tigrinus) Liquid CultureHow Is Tiger Sawgill (Lentinus tigrinus) Classified?
The currently accepted name is Lentinus tigrinus (Bull.) Fr., established by Elias Magnus Fries in 1825 in Syst. orb. veg., page 78. The basionym is Agaricus tigrinus Bull. (1782), described by the French mycologist Jean Baptiste François Pierre Bulliard, who placed all gilled fungi in Agaricus as was standard practice at the time. Fries' 1825 transfer to Lentinus gives the species its current name and makes Fries both the transferring and sanctioning author under the botanical code. Index Fungorum and MycoBank registration number: 164542.
| Rank | Taxon |
|---|---|
| Kingdom | Fungi |
| Phylum | Basidiomycota |
| Subphylum | Agaricomycotina |
| Class | Agaricomycetes |
| Order | Polyporales |
| Family | Polyporaceae |
| Genus | Lentinus Fr. |
| Species | Lentinus tigrinus (Bull.) Fr. |
The Panus tigrinus problem
The synonym Panus tigrinus (Bull.) Singer (1951) is practically significant and should not be dismissed as simply a wrong name. Rolf Singer's 1951 reassignment to Panus was widely adopted for decades, and much European and Russian biochemical and enzymological literature—especially from the late 20th century—uses Panus tigrinus or Lentinus (Panus) tigrinus. Researchers searching for laccase, ligninolytic enzymes, or phenol biodegradation studies for this species must search both names to capture the full literature.
Other notable synonyms include Lentodium squamulosum Morgan (1895), described specifically for the sealed, gastroid form found in North America, and Lentinus ravenelii Berk. & Curtis (1849), described from South Carolina material that may represent a distinct North American lineage.
Active taxonomic dispute (2023–present)
Preliminary molecular analyses from the Hibbett Lab at Clark University, building on earlier work by Grand et al. (2011), indicate that Lentinus tigrinus as currently circumscribed contains at least four distinct genetic lineages: North American, Caribbean, South and Southeast Asian, and European/Asian. The Eurasian lineage holds the type name. North American material would require a different epithet if formally split—the oldest available name is ravenelii, but there is active discussion about conserving squamulosum on ethical grounds, since ravenelii honors a slaveholder. This naming debate is ongoing and unresolved as of March 2026.
How Do You Identify Tiger Sawgill (Lentinus tigrinus)?
Macroscopic features
Microscopic features
Spores are cylindrical to narrowly ellipsoid, smooth, hyaline in KOH, inamyloid (do not react with Melzer's reagent), 5–8 × 2–4 µm (MushroomExpert data) or 6–10 × 2–3 µm (First Nature), with Q approximately 2.0–2.5. Basidia are 4-spored and clavate. Pleurocystidia (cystidia on gill faces) are absent. Cheilocystidia are basidiole-like with thick-walled binding hyphae protruding from the lamellar edge.
The most diagnostically significant microscopic feature is the presence of hyphal pegs on the gill surface: extensions measuring 40–60 µm from the hymenium, 12–30 µm wide in aggregate, composed of smooth, hyaline, thin-walled, clamped hyphae 4–6 µm wide. Hyphal pegs are a structural feature of polypore gill surfaces and are a key indicator of Lentinus sensu stricto's polypore heritage. The pileipellis is a partially gelatinized cutis of upright fascicled elements forming the visible scales, with clamped hyphae 2.5–7 µm wide. The overall hyphal system is dimitic.
The secotioid form
In North American populations, roughly half of all fruiting bodies may be secotioid: the gill edges are bridged by a proliferating hyphal weft that seals the hymenium inside the cap. Spores develop but cannot be discharged aerially; dispersal depends on the membrane tearing or insect activity. At first encounter, secotioid specimens can resemble small puffballs or immature gastroid fungi and may not be recognized as L. tigrinus at all. This form is genetically controlled by a single recessive allele—not a disease, not an environmental aberration.
Key lookalikes
Lentinellus michneri
Moderate — same wet-wood habitatLacks the radial dark scales of Tiger Sawgill; gill serration is much more pronounced and irregular; classified in Russulales, not Polyporales; lacks hyphal pegs microscopically. Grows in similar riparian habitats and can co-occur with Tiger Sawgill.
Neolentinus lepideus
Low — different substrateGrows on conifers, not hardwoods. Larger; scales rougher and broader; often has a distinctive anise odor. The conifer substrate preference alone separates it in almost all cases.
Polyporus squamosus (Dryad's Saddle)
Low — has pores, not gillsMuch larger; has a poroid (pored) undersurface, not gills; black stem base; overlapping scale pattern rather than radial stripes. Separation at a glance.
Where Does Tiger Sawgill (Lentinus tigrinus) Grow?
Tiger Sawgill (Lentinus tigrinus) is the most widely distributed species in the genus Lentinus, with documented records from 17 countries. It grows primarily on dead hardwood in or immediately adjacent to water—rivers, streams, swamps, and seasonally flooded floodplains. In well-surveyed New England river habitats, the Hibbett Lab has reported nearly every piece of wet wood bearing Tiger Sawgill fruiting bodies during summer, making it reliably abundant in its preferred microhabitat despite being rarely encountered by foragers who don't access waterlogged woodland.
Primary documented hosts include willow (Salix spp.; dominant in European carr woodland), poplar (Populus spp.), elm (Ulmus spp.), silver maple (Acer saccharinum; especially favored in eastern North American floodplains), buttonbush (Cephalanthus occidentalis), mulberry (Morus), oak, ash, and hornbeam. Wood that is partially or fully submerged is the defining microhabitat preference—a trait unusual among cultivated mushrooms and relevant to substrate moisture considerations in cultivation.
| Region | Key Countries | Notes |
|---|---|---|
| Europe | France (type locality), UK, Spain, Germany, Turkey, Russia | Willow carr specialist; uncommon to rare in UK |
| North America | USA (east of Great Plains; scattered SW), Mexico, Caribbean | Silver maple floodplains; secotioid form occurs here |
| Asia | Iran, Pakistan, India, Philippines, China | Multiple cultivation studies; May–Oct fruiting in tropics |
| Africa / Australasia | Nigeria; Australia (scattered records) | Wild collection documented; limited study |
Seasonal patterns vary by latitude. In temperate regions (Europe, North America), fruiting peaks in summer through autumn, with June–August peak in the northeastern USA. Philippine and other tropical strains fruit May–October. A notable ecological resilience: during the 2022 flash drought in New England, Tiger Sawgill continued fruiting by growing lower on partially submerged wood while most other edible species failed entirely due to soil desiccation.
As a white-rot fungus, Tiger Sawgill (Lentinus tigrinus) causes 21.49% lignin reduction and 53.26% cellulose reduction in wheat straw during growth and fruiting. It produces laccase, versatile peroxidase (VP), and manganese peroxidase (MnP)—a ligninolytic enzyme suite that has attracted substantial biotechnology research interest independent of any cultivation value.
Can You Cultivate Tiger Sawgill (Lentinus tigrinus)?
Tiger Sawgill (Lentinus tigrinus) is cultivable. It is a white-rot saprotroph with no mycorrhizal dependency and no requirement for a living host. Published cultivation studies exist from Argentina, the Philippines (multiple groups since 2012), Pakistan, Turkey, and Iran. It is not yet commercially cultivated at scale but is considered a strong candidate for development, with biological efficiency up to 62% documented under optimized conditions.
The most important practical reality for cultivators is strain variation. Among 11 Philippine strains tested on identical substrates under identical conditions, yield ranged from 4.33 to 81.83 g/bag and biological efficiency (BE) from 0.87% to 16.37%. Strain selection is not a secondary variable—it is the primary determinant of outcome. High-performing strains from the Argentine study achieved 62% BE on supplemented willow sawdust, while many baseline Philippine strains on rice straw–sawdust without optimization yielded much less.
Agar culture behavior
Fruiting body production
Liquid culture → grain spawn
Inoculate sterilized grain (rice, sorghum, or barley) from LC syringe. Sorghum colonized fastest in Pakistan work (19 days). Incubate at 30–35°C in darkness. Full colonization in 19–30 days depending on grain type and bag size.
Substrate preparation
Hardwood sawdust is the primary substrate. Best documented options: supplemented willow or hardwood sawdust (62% BE, Argentine study); sawdust + wheat bran 5–10% (Turkey; shortened spawn run); sawdust + rice straw 1:1 (292 g / 800 g substrate, Pakistan). Sterilize fully before inoculation.
Spawn run
30°C is optimal for colonization across most published studies (35°C also documented). 500 g bags: 28–30 days. Smaller 100 g volumes: 10–14 days. Maintain darkness during spawn run.
Fruiting conditions
Drop temperature to 25°C for primordia initiation—highest BE in Argentine study at 25°C. Maintain 80–90% relative humidity. Blue LED lighting specifically documented to improve yield and BE. Primordia appear in 11–16 days after induction (Argentine strain); 20–44 days (Philippine strains).
About the Out-Grow Liquid Culture
Out-Grow's Tiger Sawgill liquid culture is a 12cc syringe of viable Lentinus tigrinus mycelium in a nutrient-rich sterile solution. It is intended for grain spawn inoculation, agar plate expansion, and substrate colonization trials. The fastest and most contamination-resistant workflow is LC → sterilized grain → hardwood sawdust substrate. Supplementing sawdust with wheat bran (5–10%) or rice bran accelerates spawn run and has been shown to improve yield in Turkish and Pakistani studies. Philippine submerged fermentation work also confirms this species performs well in static liquid culture for mycelial biomass production at 30°C.
What Bioactive Compounds Does Tiger Sawgill (Lentinus tigrinus) Contain?
Tiger Sawgill (Lentinus tigrinus) has been studied for nutritional composition, ligninolytic enzymes, antioxidant capacity, antimicrobial activity, and preliminary pharmacological properties. The strongest and most replicated findings concern its laccase enzymes—among the best-characterized in any mushroom species.
Nutritional profile (dry weight)
| Component | Pileus (cap) | Stipe (stem) |
|---|---|---|
| Crude protein | 25.9% | 11.7% |
| Total carbohydrate | 57.8% | 67.7% |
| Dietary fiber | — | 63.0% |
| Fat (lipid) | 2.1% | 1.0% |
| Ash | 7.4% | 5.5% |
| Energy | 142.1 kcal/100g | 84.2 kcal/100g |
| Total phenol | 4.16 ± 0.08 mg GAE/g (dry) | — |
Lysine is the dominant L-amino acid in soluble protein. Mineral profile shows high potassium, phosphorus, sulfur, and magnesium; low sodium; no toxic heavy metals exceeding joint FAO/WHO standards.
Bioactive compounds
59 kDa Laccase
In vitro — enzyme assayPurified 95-fold from mycelial culture broth. Specific activity 76.6 U/mg; optimal pH 4; optimal temperature 60°C. Showed HIV-1 reverse transcriptase inhibition with IC₅₀ = 2.4 µM in a cell-free enzyme assay. No antiviral activity demonstrated in cell models or animal studies. Mechanistically interesting; not clinically established.
Laccase (industrial)
Biotechnology applicationsActivity on birch sawdust: 20 U/g (vs. 2.3 U/g on pine). Used for biobleaching Acacia kraft pulp. Biodegrades phenol concentrations up to 5% in liquid medium (Russian strain VKM F-3616D). Biotransforms soil humic acids with versatile peroxidase.
Antioxidant capacity
Ex vivo spectrophotometricTotal antioxidant status (TAS): 1.748 ± 0.071 mmol Trolox eq/L. Total oxidant status (TOS): 19.294 ± 0.237 µmol H₂O₂ eq/L. Oxidative stress index (OSI): 1.106 ± 0.031. Measured on Turkish fruiting body extract via Rel Assay kit.
Antimicrobial activity
In vitro — disc diffusionActive against Candida albicans, C. krusei, C. glabrata, S. aureus (including MRSA), E. coli, B. subtilis, and others across ethanol, methanol, DCM, and aqueous extracts. No MIC values published in available abstracts. No animal or human data.
Hypoglycemic activity
Animal model onlyHot water fruiting body extract at 100–250 mg/kg oral dose lowered blood glucose by 26.9% at week 3 in alloxan-induced diabetic mice, comparable to glibenclamide at similar dosing. No mechanism identified. No human data.
Anticancer (selective)
In vitro cell linesAt 100–250 µg/mL: 70% kill rate of MCF-7 (breast carcinoma) cells; selective cytotoxicity confirmed against MCF-7 but not PC3 (prostate). No adverse effects on normal human/mouse cells at these concentrations. No in vivo tumor model data. No human trials.
Is Tiger Sawgill (Lentinus tigrinus) Safe to Eat?
Tiger Sawgill (Lentinus tigrinus) is classified as edible and has been consumed in the Philippines, parts of tropical Asia, and experimentally in multiple cultivation studies across Turkey, Argentina, Iran, and Pakistan. No human poisoning cases or adverse dietary events have been documented in the peer-reviewed literature. Mouse acute toxicity studies (both oral and intraperitoneal routes) found no adverse effects at tested doses.
Three safety findings require accurate contextualization:
IV injection LD₅₀ (Iran study): 47.19 mg/mL by intravenous injection in mice. Intravenous injection is not a relevant exposure route for dietary or supplement consumption. This finding has no bearing on safety of cooking and eating this mushroom.
Zebrafish embryotoxicity (Philippines): Hot water extract at concentrations of 1% and above significantly reduced hatchability of zebrafish (Danio rerio) eggs; concentrations of 5% and above affected heart rate; concentrations of 0.5–10% caused developmental delay and malformations. Zebrafish embryo assays are a toxicological screening tool conducted in high-concentration direct contact with developing embryos—they are not predictive of adult human dietary safety at typical serving sizes. These findings document biological activity at high concentrations and should be disclosed, but they do not constitute evidence of dietary risk from normally prepared and cooked mushrooms.
Limited human consumption history: Unlike oyster mushrooms or shiitake with centuries of widespread use, Tiger Sawgill has primarily been consumed in limited tropical regions. The absence of documented poisonings partly reflects genuine low toxicity and partly reflects limited large-scale consumption. Thorough cooking using standard culinary practice is appropriate. No dermal irritants or preparation-dependent toxins have been identified.
What Makes Tiger Sawgill (Lentinus tigrinus) Remarkable?
Tiger Sawgill (Lentinus tigrinus) occupies a genuinely singular position in fungal biology—it is a research organism with no close competitor for several of the questions it uniquely enables.
A polypore that evolved gills
The Lentinus/Polyporellus clade within Polyporaceae evolved lamellate gills from ancestral circular pores. Tiger Sawgill retains microscopic evidence of its polypore ancestry: the hyphal pegs on the gill surface are a structural character of polypore gill surfaces, not found in evolutionarily independent gilled mushrooms. It is arguably the best North American illustration of evolutionary convergence between the gilled-mushroom and polypore growth forms—and it belongs unambiguously in the polypore family.
The single-gene fruiting body switch
The secotioid form—sealed, gastroid, spore-trapping—is controlled by a single recessive allele at one genomic locus. This makes Tiger Sawgill the world's best model for studying how a single genetic change can redirect the entire developmental program of a fruiting body. The 907 genes differentially expressed between secotioid and agaricoid developmental stages identified by Wu et al. (2018) represent a roadmap for understanding how fruiting body architecture is genetically encoded. No other system in Polyporales offers this level of experimental resolution on this question.
The floodplain fruiting specialist
Few fungi fruit on actively submerged wood in flowing water. Tiger Sawgill's dimitic hyphal system—with its thick-walled skeletal and binding hyphae interwoven throughout the fruiting body—produces the tough, pliant, water-resistant texture that allows it to survive prolonged inundation. The 2022 drought resilience in New England, where it continued fruiting while other species failed entirely, demonstrates an ecological adaptation with no good parallel in cultivated mushrooms.
The naming dilemma
The near-certain pending species split presents a rare situation in modern mycology: the North American lineage, which includes most cultivation research, most iNaturalist observations from the USA, and most hobbyist interest, may end up renamed under an epithet honoring a slaveholder—unless the community successfully argues for conserving the descriptive name squamulosum instead. This debate is active and unresolved, making Tiger Sawgill a live case study in how scientific nomenclature intersects with ethical considerations.
The laccase with unusual in vitro properties
The 59 kDa laccase with IC₅₀ = 2.4 µM against HIV-1 reverse transcriptase in a cell-free assay is scientifically interesting not because it suggests an antiviral therapy (the distance from isolated enzyme in vitro activity to a viable drug is enormous), but because a copper-dependent oxidase that incidentally inhibits a viral polymerase through protein-protein interaction is mechanistically novel. It represents an unusual case of biological function discovered by screening beyond the enzyme's primary catalytic role.
Also available as a culture plate from Out-Grow.
Tiger Sawgill (Lentinus tigrinus) Culture PlateFrequently Asked Questions About Tiger Sawgill (Lentinus tigrinus)
Is Tiger Sawgill (Lentinus tigrinus) a polypore or a gilled mushroom?
Both, in different senses. Tiger Sawgill produces gills—the lamellate, saw-toothed structures visible on the underside of the cap—so it looks like a typical gilled mushroom. But molecular phylogenetics firmly places it in Polyporaceae, the polypore family, alongside pored bracket fungi like Dryad's Saddle. It belongs to a lineage that independently evolved gills from ancestral circular pores, and its microscopic hyphal pegs on the gill surface are a retained polypore character. It is simultaneously a gilled mushroom in form and a polypore in phylogenetic reality.
What is the secotioid form of Tiger Sawgill?
In North American populations, approximately half of all Tiger Sawgill fruiting bodies are secotioid: instead of having open, spore-releasing gills, the gill tissue is sealed inside the cap by a proliferating hyphal membrane. Spores develop normally but cannot be discharged into the air. This gastroid form is controlled by a single recessive genetic allele—not disease, not environmental damage. Both forms grow side by side at the same sites, often on the same piece of wood. The secotioid form can look like a small puffball and may be overlooked or misidentified without knowing to look for it.
Where does Tiger Sawgill grow in the wild?
Tiger Sawgill is the most widely distributed Lentinus, recorded from 17 countries. In nature it is a riparian specialist, growing on dead hardwood that is partially or fully submerged in or adjacent to rivers, streams, swamps, and seasonally flooded floodplains. Primary hosts include willow, poplar, elm, and silver maple. In temperate North America it fruits in summer through autumn, peaking June–August in the northeastern USA. In the UK it is uncommon to rare, primarily due to the inaccessibility of carr woodland habitat rather than scarcity of the organism itself.
What substrate works best for cultivating Tiger Sawgill?
Supplemented hardwood sawdust is the best documented substrate, with the highest reported biological efficiency (62%) coming from supplemented willow sawdust in the Argentine study. Sawdust + wheat bran (5–10%) or sawdust + rice straw in roughly 1:1 ratio are practical options with published yield data from Turkey, Pakistan, and the Philippines. Strain selection is the most critical variable—among 11 Philippine strains tested on identical substrates, yield ranged from 4.33 to 81.83 g/bag. Spawn run is best at 30°C; fruiting initiation benefits from a temperature drop to 25°C and 80–90% relative humidity.
Is Tiger Sawgill safe to eat?
Tiger Sawgill (Lentinus tigrinus) is classified as edible. It has been consumed in the Philippines and parts of tropical Asia, and multiple cultivation studies across Argentina, Turkey, Iran, and Pakistan have included edibility assessment. No human poisoning cases have been documented. Mouse acute toxicity studies found no adverse effects by oral route. A zebrafish embryo study found developmental effects at high extract concentrations, but this type of assay is a toxicological screening tool not directly predictive of adult human dietary safety. Thorough cooking and accurate identification (avoid secotioid form confusion with gastroid fungi) are standard precautions.
What is the difference between Lentinus tigrinus and Panus tigrinus?
They are the same species—Panus tigrinus is a synonym, not a separate organism. Rolf Singer transferred the species to Panus in 1951, and this name was widely used for decades, especially in European and Russian enzymological and biochemical literature. Singer's placement is now rejected by molecular phylogenetics, and the correct current name is Lentinus tigrinus. However, anyone searching for laccase, phenol biodegradation, or ligninolytic enzyme studies on this species must search both names to capture the full literature—many important papers use Panus tigrinus or Lentinus (Panus) tigrinus.