Oregon White Truffle (Tuber oregonense)
Oregon White Truffle (Tuber oregonense)
Oregon White Truffle (Tuber oregonense) is a hypogeous (underground-fruiting) edible fungus native to the Pacific Northwest coast of North America, prized for its pungent, complex aroma. It forms a mutually beneficial partnership with Douglas-fir roots, making it impossible to grow on conventional mushroom substrates. Commercially harvested each winter from Oregon and Washington forests, it is one of the few native North American truffles to reach fine-dining tables.
Tuber oregonense Trappe, Bonito & P. Rawl. (2010) — Family Tuberaceae — Order Pezizales
Oregon White Truffle (Tuber oregonense) is North America's premier native winter truffle — a subterranean fungus that fruits beneath Douglas-fir needles in the rain-soaked forests west of the Cascades. Unlike the celebrated European black and white truffles it resembles in price and prestige, T. oregonense carries a distinctly Pacific Northwest character: herbal and garlicky with petroleum-like top notes, shaped by the needle-rich topsoil and cool maritime climate of its home range. Described as a new species only in 2010, it was long confused with its spring-fruiting relative Tuber gibbosum — a mix-up that still persists in trade. As foraging interest and gastronomy have grown, so has curiosity about cultivation, though the biology of Oregon White Truffle (Tuber oregonense) makes it one of the most challenging fungi any grower could attempt.
What Is the Oregon White Truffle (Tuber oregonense)?
The Oregon White Truffle (Tuber oregonense) is a member of the genus Tuber — the true truffles — a group of subterranean, sac-fungus relatives (Ascomycota) that produce their spores inside enclosed fruit bodies hidden beneath the soil surface. The genus is best known for its European commercial species, T. melanosporum (Périgord black truffle) and T. magnatum (Italian white truffle), but T. oregonense represents the Western North American counterpart to that tradition, one of perhaps four closely related cryptic species now recognized within what mycologists call the Tuber gibbosum complex.
What makes Oregon White Truffle (Tuber oregonense) remarkable among North American fungi is its combination of genuine culinary merit, ecological specificity, and commercial significance. Unlike the vast majority of wild-harvested mushrooms in the Pacific Northwest, which are sold regionally or dried, the Oregon White Truffle (Tuber oregonense) commands prices comparable to premium European truffles and is served shaved over pasta and eggs in high-end restaurants. Its aroma — described variously as garlic, cheese, herbs, spices, and petroleum — develops rapidly as the fruit body matures and is the primary measure of harvest timing and quality.
Oregon White Truffle (Tuber oregonense) was formally named as a distinct species only in 2010. Before that, it was informally treated as a variety of Tuber gibbosum. Molecular work using ITS and LSU rDNA markers finally confirmed it as a separate lineage — a finding with real consequences for foraging phenology, ecological data, and culinary labeling.
The Oregon White Truffle (Tuber oregonense) fruits underground as what mycologists call a hypogeous (meaning "below ground") ascocarp (the technical term for the spore-bearing structure in sac fungi). It does not emerge above the soil surface the way gill mushrooms do. Instead, it relies entirely on animals — particularly small mammals like the northern flying squirrel — to dig it up, consume it, and disperse its spores through their feces. This mammal-mediated spore dispersal is not incidental: it is the primary mechanism by which Oregon White Truffle (Tuber oregonense) reproduces across the landscape.
Within Pacific Northwest ecosystems, Oregon White Truffle (Tuber oregonense) is a quiet but significant player, contributing to soil nutrient cycling, tree health, and food web dynamics across tens of thousands of acres of coastal Douglas-fir forest. Its biology is inseparable from its habitat.
How Is Oregon White Truffle (Tuber oregonense) Classified?
| Kingdom | Fungi |
| Phylum | Ascomycota |
| Class | Pezizomycetes |
| Order | Pezizales |
| Family | Tuberaceae |
| Genus | Tuber |
| Species | Tuber oregonense Trappe, Bonito & P. Rawl. 2010 |
| MycoBank ID | MB515123 |
Oregon White Truffle (Tuber oregonense) belongs to the Gibbosum clade, one of nine major species groups within the genus Tuber recognized by modern LSU and ITS-based phylogenies. The other eight clades — Aestivum, Excavatum, Macrosporum, Magnatum, Melanosporum, Puberulum, Rufum, and Spinoreticulatum — contain the more familiar European commercial and culinary truffles. The Gibbosum clade is North American and currently comprises at least four species: T. oregonense, T. gibbosum, T. castellanoi, and T. bellisporum.
The formal description of Oregon White Truffle (Tuber oregonense) was published in 2010 by James Trappe, Gregory Bonito, and Patricia Rawlinson in the journal Mycologia (Bonito et al., Mycologia 102:1053, 2010). Prior to this work, the organism was informally treated as Tuber gibbosum var. oregonense, but ITS and LSU sequence data demonstrated sufficient divergence to warrant recognition at the species level. It is not a recombination of an earlier name — the 2010 binomial is the original and only accepted name in MycoBank and Index Fungorum. There are no formal synonyms.
The informal label "Oregon white truffle" predates the formal species description and is shared with Tuber gibbosum (the spring Oregon white truffle). In trade and some foraging literature, the two species are still lumped together under the same common name. The seasonal qualifier — "winter Oregon white truffle" for T. oregonense, "spring Oregon white truffle" for T. gibbosum — is the clearest practical distinction outside of microscopy.
For molecular identification, the primary barcode marker is the ITS (internal transcribed spacer) region of nuclear ribosomal DNA. The key reference sequence for Oregon White Truffle (Tuber oregonense) is GenBank accession FJ809874, specimen DUKE GB284, cited across multiple later truffle phylogenies. Because ITS alone may not be sufficient to resolve all specimens within the closely related Gibbosum clade, combined ITS + LSU analysis is recommended for confident species-level identification of ambiguous material. RPB2 and EF1-α data exist for some Tuber species but are sparse for T. oregonense specifically.
How Do You Identify Oregon White Truffle (Tuber oregonense)?
Oregon White Truffle (Tuber oregonense) is a hypogeous, roughly spherical to irregularly lobed fruit body. Confident identification requires assessing macroscopic characters in the field, microscopic characters under a compound microscope, and — for definitive distinction from its closest relatives — molecular analysis.
Morphology
The peridium (outer skin) of Oregon White Truffle (Tuber oregonense) opens white and clean, then develops reddish-orange patches as the fruit body matures, eventually turning uniformly orange-brown to reddish-brown and often cracking or fissuring at over-maturity. The surface texture ranges from smooth to finely hairy, with hyphal hairs denser inside the furrows. The interior — called the gleba — shows the classic marbled white-vein pattern of the white truffle group: solid white tissue at first, then progressively browning as spores mature, while the narrow white veins remain conspicuous throughout.
Developmentally, young Oregon White Truffle (Tuber oregonense) fruit bodies are the hardest to identify: they are small, white, and nearly odorless, closely resembling immature T. gibbosum and other hypogeous ascomycetes. As the fruit body swells and the spores mature, the aroma builds rapidly — this intensification is the single most reliable signal of approaching peak harvest quality. Over-mature specimens turn uniformly dark, develop off-odors, and decline rapidly in culinary value.
Microscopic Features
Under compound microscopy, Oregon White Truffle (Tuber oregonense) spores are broadly ellipsoid, covered with a thick, alveolate (honeycomb-patterned) reticulum (network of ridges) with walls 2–3 µm thick. Spore dimensions depend on how many spores are packed per ascus (the spore-containing sac): 1-spored asci yield the largest spores (42.5–62.5 × 25–40 µm), while 4-spored asci produce spores of 25–38.5 × 13–28 µm. The asci themselves are mature at 60–85 × 65–75 µm, typically containing 1–4 spores, occasionally 5. Clamp connections are absent — consistent with all known Pezizomycetes. Peridial hyphae are tightly interwoven, hyaline, 3–5(–10) µm broad.
Lookalike Species
The primary lookalike. Macro-morphology and odor overlap so strongly that season is the most reliable field separator: T. gibbosum fruits mainly February–June, while T. oregonense peaks in mid-winter. Spore dimensions at a given spore count per ascus differ slightly, with T. oregonense tending toward larger, more strongly ornamented spores. Definitive separation requires microscopy or molecular data. Both species are edible — mislabeling is a commercial, not safety, concern.
Two other Gibbosum-clade species occurring in the same Pacific Northwest range, both white-marbled and nearly indistinguishable macroscopically from T. oregonense. Separation requires detailed spore measurements and molecular analysis. Neither is known to be toxic.
Various non-truffle underground fungi can superficially resemble immature Oregon White Truffle. They typically differ in gleba color and structure, host association, and spore morphology. Regional field guides caution beginners against relying on exterior appearance alone. None of the common PNW imposters are dangerous, but identification should be confirmed before consumption.
The Tuber gibbosum complex contains at least four cryptic species that were historically lumped under one name. Field separation of T. oregonense from its closest relatives using macroscopic characters alone is unreliable except by season. Any collector or researcher requiring species-level certainty should use combined ITS + LSU sequencing rather than morphology alone.
Where Does Oregon White Truffle (Tuber oregonense) Grow?
Oregon White Truffle (Tuber oregonense) is ectomycorrhizal — a word that describes a mutually beneficial partnership (symbiosis) between the fungus and a living tree host. In this arrangement, the fungal mycelium (the thread-like vegetative body) wraps around and colonizes the fine roots of the host tree. The fungus supplies mineral nutrients, particularly phosphorus and nitrogen, and water to the tree; in exchange, the tree supplies sugars and other carbon compounds produced by photosynthesis. This partnership is obligate for Oregon White Truffle (Tuber oregonense): the fungus cannot complete its life cycle without a living host root network, which has profound implications for cultivation.
The primary host is Douglas-fir (Pseudotsuga menziesii), the dominant conifer of the Pacific Northwest coast. Oregon White Truffle (Tuber oregonense) also associates with western hemlock (Tsuga heterophylla), Sitka spruce (Picea sitchensis), and alder species (Alnus spp.) in mixed stands, but Douglas-fir is the ecological core of its range and the tree most strongly associated with productive harvest sites.
| Region | Status | Peak Season | Key Notes |
|---|---|---|---|
| Western Oregon | Common; most heavily harvested | January–February | Core commercial production area; Oregon Truffle Festival (Eugene) |
| Western Washington | Common | December–February | Significant forager and commercial activity |
| Southern British Columbia | Present; less documented | October–January | Northern limit of documented range |
| Northern California | Present at range margin | November–February | Spotty records; southern extent uncertain |
Oregon White Truffle (Tuber oregonense) typically occurs from near sea level up to approximately 425 m elevation. Fruiting bodies are buried in the upper mineral soil or at the interface between the organic duff layer and mineral soil, usually 2–10 cm below the surface under Douglas-fir needle litter and among fine roots. Well-drained soils with abundant organic litter and intact ectomycorrhizal root networks favor fruiting; compacted, heavily disturbed, or waterlogged soils are less productive.
Stand age is a significant variable. Oregon White Truffle (Tuber oregonense) is most commonly associated with younger to early-mature Douglas-fir stands, roughly 15–40 years old in plantations and up to about 100 years old in natural or mixed stands. Christmas tree plantations of Douglas-fir — sometimes as young as five years — have been noted as productive fruiting sites, fueling interest in plantation-based truffle harvest systems.
Ecologically, Oregon White Truffle (Tuber oregonense) plays a meaningful role beyond its relationship with trees. Northern flying squirrels consume it as a significant dietary component during the winter months, creating an ecological link between the truffle, small mammals, and the predators — including owls and other raptors — that depend on those mammals. Animal consumption and the subsequent dispersal of spores through feces is central to how Oregon White Truffle (Tuber oregonense) spreads and colonizes new sites across the landscape.
Can You Cultivate Oregon White Truffle (Tuber oregonense)?
Cultivating Oregon White Truffle (Tuber oregonense) is among the most difficult challenges in applied mycology. Because it is obligately ectomycorrhizal — meaning it requires a living tree root system to complete its life cycle — it cannot be grown on the sterilized grain, sawdust, or straw substrates used for saprotrophic (decomposer) mushrooms like oysters or shiitakes. Any realistic cultivation approach must involve establishing and maintaining the truffle's symbiosis with a living Douglas-fir or compatible host tree.
There are currently no published, reproducible, peer-reviewed protocols demonstrating controlled plantation-based fruiting of Tuber oregonense at scale. Evidence for "cultivation" remains limited to anecdotal or gray-literature reports. Any product or method claiming to reliably fruit Oregon White Truffle (Tuber oregonense) on a predictable timeline should be evaluated critically against this fact.
The Ectomycorrhizal Barrier
Successful Oregon White Truffle (Tuber oregonense) cultivation in any meaningful sense requires three overlapping biological achievements: establishing mycorrhizal colonization of tree seedling roots; growing those seedlings into productive plantation trees over years to decades; and maintaining conditions — soil pH, moisture, stand structure, competing fungal communities — that allow the truffle to persist and eventually fruit. Each step carries substantial uncertainty.
In the field, mycorrhizal establishment can take months to several years after planting inoculated seedlings, depending on inoculum quality and ecological competition. The principal contamination risk in truffle cultivation is not bacterial mold but ecological displacement: native ectomycorrhizal fungi — Russula, Cortinarius, non-target Tuber species — colonize the same root systems and can outcompete the desired truffle, especially in established soils with intact native mycorrhizal communities.
Experimental and Reported Field Methods
Seedling Inoculation
Douglas-fir seedlings are inoculated with T. oregonense mycelium or spore material in greenhouse conditions, aiming to establish ectomycorrhizal colonization before field planting.
Field Planting
Inoculated seedlings are planted in suitable soils — well-drained, appropriate pH, low competing mycorrhizal load. Christmas tree farms and managed plantations are the primary experimental sites.
Stand Management
Canopy cover, soil moisture, and competing fungi are managed over years. Optimal stand age for fruiting is roughly 15–40 years, though anecdotal fruiting has been reported in younger Christmas tree stands.
Slurry Inoculation (Anecdotal)
Some growers report spreading ground truffle in water under established trees. There is no controlled evidence that this reliably establishes new truffle patches, but it remains a widely discussed field method.
A patent (WO2017098509A1) on ectomycorrhizal cultivation systems explicitly lists Oregon White Truffle (Tuber oregonense) among target species, indicating at least conceptual inclusion in advanced mycorrhizal inoculation strategies involving containers attached to tree stems. However, patent inclusion does not imply validated field performance.
Agar and Liquid Culture
No species-specific, peer-reviewed data on T. oregonense mycelial behavior in agar or liquid culture have been published. What follows is extrapolated from broader Tuber culture literature and applies to the genus generally, not to Oregon White Truffle (Tuber oregonense) specifically.
Realistic uses of Oregon White Truffle (Tuber oregonense) liquid culture, based on extrapolation from the broader Tuber literature, include inoculating agar plates for research isolation, experimental inoculation of sterilized or semi-sterilized Douglas-fir seedlings under controlled conditions, and production of mycelial biomass for biochemical or molecular studies. Fruiting Oregon White Truffle (Tuber oregonense) directly from liquid culture or on sterile substrate — as saprotrophic mushrooms are fruited — has no biological basis and is contrary to current ectomycorrhizal science.
No peer-reviewed study has published growth rates, preferred media, or long-term culture stability data specifically for Tuber oregonense mycelium. Agar and liquid culture behavior reported commercially for this species remains unvalidated against peer-reviewed mycological standards.
What Bioactive Compounds Does Oregon White Truffle (Tuber oregonense) Contain?
Oregon White Truffle (Tuber oregonense) contains a complex mixture of volatile organic compounds (VOCs) that drive its distinctive aroma, along with polysaccharides, proteins, lipids, phenolics, and enzymes common to fungi in the genus Tuber. However, honest accounting of the chemical literature reveals a significant gap: the compounds responsible for the specific garlic–cheese–petroleum–herbal aroma of Oregon White Truffle (Tuber oregonense) have not been identified and quantified in any published analytical chemistry study specific to this species.
No peer-reviewed studies have measured MIC (minimum inhibitory concentration against bacteria or fungi), IC₅₀ (half-maximal inhibitory concentration for biological assays), DPPH radical scavenging, FRAP antioxidant capacity, or GAE (gallic acid equivalent phenolic content) specifically for Oregon White Truffle (Tuber oregonense) fruit bodies, mycelium, or culture filtrates. Any functional or medicinal claims about this species must be clearly identified as extrapolation from other Tuber taxa and are not evidence-based for Oregon White Truffle (Tuber oregonense) specifically.
Species-specific GC-MS or GC-olfactometry profiling of Tuber oregonense volatiles has not been published. Identifying the key aroma compounds and their variation across sites, seasons, and maturity stages is among the most consequential open questions in Oregon white truffle science — with direct implications for harvest timing, quality assessment, and culinary standardization.
Is Oregon White Truffle (Tuber oregonense) Safe to Eat?
Oregon White Truffle (Tuber oregonense) is a choice edible fungus with an established informal safety record built on decades of commercial harvest, restaurant service, and consumer purchase in the Pacific Northwest. It is served raw shaved over neutral-flavored dishes — pasta, eggs, risotto — where its aroma can be fully appreciated, as heat diminishes the volatile compounds responsible for its character.
No toxic compounds, syndromes, or poisoning case reports have been documented for Oregon White Truffle (Tuber oregonense). It is not listed as a problem species in any mycological poisoning compilation or public health guidance document reviewed in the primary literature. The North American Truffling Society notes that no truffles in the genus Tuber are currently known to be toxic to humans, though this statement reflects present knowledge and does not guarantee universal safety for all individuals and conditions.
Immature or over-mature Oregon White Truffle (Tuber oregonense) specimens may cause gastrointestinal discomfort in some individuals — a pattern common to edible mushrooms consumed when not at peak condition. Individuals with known mushroom sensitivities should exercise caution. No drug interactions specific to Oregon White Truffle (Tuber oregonense) have been documented, and no preparation steps beyond normal culinary handling are required for safe consumption.
A note on evidence interpretation: the absence of documented poisoning from Oregon White Truffle (Tuber oregonense) reflects genuine widespread consumption at culinary doses and the species' commercial handling, but formal clinical or toxicological studies do not exist. "No known cases" is meaningful here precisely because the species is not obscure — it is commercially sold — but it is not the same as a fully characterized safety profile. No human clinical studies on therapeutic effects have been conducted, and no specific health claims beyond general food value are supported by the current evidence base.
What Makes Oregon White Truffle (Tuber oregonense) Remarkable?
Oregon White Truffle (Tuber oregonense) occupies a unique position in North American mycology: it is one of only a handful of native truffles on the continent that has broken through into serious commercial gastronomy, creating a regional culinary culture with few parallels in American food traditions. The annual Oregon Truffle Festival in Eugene — timed to the species' January–February fruiting peak — draws chefs, mycologists, foragers, and food writers from across the country, centering a mid-winter culinary event on what is, biologically speaking, an underground sac fungus living in the needle duff of Douglas-fir plantations.
The story of how Oregon White Truffle (Tuber oregonense) came to be recognized as a distinct species is itself a window into the molecular revolution in mycology. For decades, the Pacific Northwest's winter and spring white truffles were lumped together under the single name Tuber gibbosum. They look nearly identical in the hand and share a broadly similar aroma; the practical distinction between them — season of fruiting — was understood by experienced foragers, but the biological significance of that difference was not formalized. When Bonito, Trappe, and Rawlinson applied ITS and LSU sequencing to a range of Gibbosum-clade collections in 2010, they found not two but four cryptic species hiding under a single concept. Oregon White Truffle (Tuber oregonense) emerged as a distinct lineage, the winter species, with its own formal binomial and a place in the global Tuber phylogeny.
Oregon White Truffle (Tuber oregonense) is a major component of the winter diet of northern flying squirrels across parts of its range. Flying squirrels, in turn, are keystone prey for spotted owls, barred owls, and other raptors. The truffle's subterranean fruiting, its mammal-mediated spore dispersal, and its ectomycorrhizal role in Douglas-fir forest nutrition make it a thread woven through multiple levels of the Pacific Northwest forest ecosystem simultaneously.
The biology of Oregon White Truffle (Tuber oregonense) also poses one of the most difficult problems in applied mycology. Unlike virtually every other commercially significant edible fungus, it cannot be grown on a substrate in a fruiting chamber. Its obligate ectomycorrhizal biology means that fruiting is inseparable from a living tree root system — a fact that, combined with the multi-year timeline required for plantation establishment and the complexity of managing competing ectomycorrhizal communities, has kept Oregon White Truffle (Tuber oregonense) production almost entirely dependent on natural and semi-natural stands. The contrast with European truffle cultivation — where Tuber melanosporum is now produced in planned orchards across France, Spain, Australia, and the United States — highlights how much species-specific biology shapes what is possible in practice. Oregon White Truffle (Tuber oregonense) cultivation lags at least two decades behind its European counterparts in reproducible, documented methodology.
Perhaps the deepest open question surrounding Oregon White Truffle (Tuber oregonense) is chemical: despite being a commercially harvested edible fungus with a distinctive, widely celebrated aroma, no species-specific GC-MS analysis of its volatile compounds has been published. The garlic-cheese-petroleum-herbal character that commands premium prices in the marketplace has no identified molecular basis in the peer-reviewed literature specific to this species. Every aroma description in trade and gastronomy is qualitative, grounded in human perception rather than analytical chemistry. For a species this commercially significant, that gap is striking — and closing it would have practical consequences for understanding harvest timing, terroir variation, and quality standardization.
Frequently Asked Questions About Oregon White Truffle (Tuber oregonense)
What is the difference between Oregon White Truffle (Tuber oregonense) and Tuber gibbosum?
Tuber oregonense is the winter species, fruiting mainly September through mid-March with a peak in January–February. Tuber gibbosum is the spring species, fruiting mainly February through June. The two are nearly identical macroscopically and in aroma; reliable field separation relies primarily on season. Definitive species-level identification requires microscopy (spore dimensions at a given ascus spore count) or molecular sequencing (ITS + LSU). Both species are edible and of comparable culinary quality — mislabeling between them is a commercial and phenological concern, not a safety issue.
Can Oregon White Truffle (Tuber oregonense) be cultivated at home?
Not in any conventional sense. Oregon White Truffle (Tuber oregonense) is obligately ectomycorrhizal and requires a living Douglas-fir or compatible host tree root system to complete its life cycle. It cannot be fruited on sterilized grain, sawdust, straw, or other typical mushroom substrates. Cultivation requires planting inoculated tree seedlings and managing them for years to decades before fruiting may occur — and no peer-reviewed, reproducible protocol has demonstrated reliable plantation-based production at scale. Agar or liquid culture of the mycelium is possible in principle, but is used for research and experimental tree inoculation, not for direct fruiting.
When and where is the best time to find Oregon White Truffle (Tuber oregonense)?
Peak maturity falls in January and February in western Oregon and Washington, though the fruiting season extends from approximately September through mid-March. Look under Douglas-fir needle duff in well-drained soils on the west side of the Cascade Range, from near sea level to about 425 m elevation. Young to early-mature Douglas-fir stands (15–40 years in plantations) tend to be the most productive. Christmas tree farms are frequently cited fruiting sites. A trained truffle dog is the most reliable detection tool, as the fruit bodies are buried 2–10 cm underground and invisible to direct search.
What does Oregon White Truffle (Tuber oregonense) smell and taste like?
The aroma of a mature Oregon White Truffle (Tuber oregonense) is strong, pungent, and complex: most describers note garlic, spiced cheese, herbs, and a petroleum or chemical top note, with culinary sources often emphasizing a floral or herbal quality compared with European truffles. The aroma develops rapidly as the fruit body approaches maturity and is the primary indicator of harvest readiness. Importantly, the specific volatile compounds responsible for this aroma have not been identified in any published analytical chemistry study specific to T. oregonense — every description is based on sensory perception, not GC-MS data.
Is Oregon White Truffle (Tuber oregonense) safe to eat?
Yes. Oregon White Truffle (Tuber oregonense) is a choice edible with decades of commercial harvest, restaurant use, and consumer consumption in the Pacific Northwest. No toxic compounds or poisoning cases have been documented. As with any edible fungus, over-mature or poorly stored specimens may cause gastrointestinal discomfort in some individuals. Standard culinary use — typically raw or very lightly heated to preserve the volatile aroma — is safe for the general population. Individuals with general mushroom intolerances should exercise normal caution.
Why was Oregon White Truffle (Tuber oregonense) only described as a species in 2010?
Before the application of molecular phylogenetics to the group, the Pacific Northwest white truffles were assessed primarily by morphology, and the visual and aromatic similarity between T. oregonense and T. gibbosum was sufficient to keep them informally grouped together, sometimes as a variety of T. gibbosum. When Bonito, Trappe, and Rawlinson applied ITS and LSU ribosomal DNA sequencing to collections from across the gibbosum complex in 2010, they resolved at least four cryptic species with strong molecular support. Oregon White Truffle (Tuber oregonense) — the winter-fruiting member — emerged as a distinct lineage, receiving its own formal binomial in a paper published in Mycologia.