Chronicles of 

Fibroporia radiculosa

(= Antrodia radiculosa) 

TFFH 294

Carol A. Clausen

Katie M. Jenkins

United States

Department of

Agriculture

Forest Service

Forest

Products

Laboratory

General

Technical

Report

FPL–GTR–204
November 2011

Clausen, Carol A.; Jenkins, Katie M. 2011. Chronicles of Fibroporia radiculosa (= Antrodia radiculosa) TFFH 294. General Technical Report FPLGTR-204. Madison, WI: U.S. Department of Agriculture, Forest Service, 

Forest Products Laboratory. 5 p.

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Abstract

The brown-rot fungus, Fibroporia radiculosa, has been 

included in numerous research studies because many isolates of this fungus demonstrate an unusually high tolerance 

to copper. This fungus has undergone several recognized 

changes in taxonomic nomenclature, and through DNA 

technology, scientists have correctly identified isolates that 

had been misidentified microscopically. Fibroporia radiculosa is not uncommon. In fact, the isolation and prevalence 

of Fibroporia radiculosa has been documented by mycologists since the 1930s, but the mechanism of copper tolerance 

remains a mystery. Here, we look at the history of research 

involving Fibroporia radiculosa and trace the changes in 

taxonomic nomenclature. 

Keywords: Fibroporia radiculosa, Antrodia radiculosa, 

TFFH 294, taxonomic nomenclature

Acknowledgment

Authors thank Jessie Glaeser, Research Plant Pathologist, 

Northern Research Station, for providing historic reference 

materials.

Cover Caption: Fibroporia radiculosa growing on treated 

wood in the Harrison Experimental Forest in Mississippi 

and growing on culture medium in the laboratory, Forest 

Products Laboratory.

Contents

History................................................................................1

 Historical References.....................................................2

Bioremediation (1996 to 2006)..........................................2

 Bioremediation References............................................2

Role of Oxalic Acid Production in Copper Tolerance 

(1999 to present) ................................................................2

 Oxalic Acid References..................................................3

Genetic Analysis (2005 to 2011)........................................4

 Genetics References.......................................................4

Metal Tolerance (2009)......................................................4

 Metal Tolerance References...........................................4

Future Research: Mechanism of Copper Tolerance 

(2010 to Present)................................................................4

 Mechanism References..................................................5

Nomenclature (1921 to Present) ........................................5

 Nomenclature References..............................................5
Chronicles of Fibroporia radiculosa

(= Antrodia radiculosa) TFFH 294

Carol A. Clausen, Supervisory Research Microbiologist

Katie M. Jenkins, Biological Science Technician

Forest Products Laboratory, Madison, Wisconsin

History

The Forest Products Laboratory (FPL) has played an important role in evaluating field performance of wood preservatives since it was established in 1910. Field performance 

is determined by placing wood specimens that have been 

treated with preservative formulations in field plots that 

have a high decay hazard potential. Decay hazard potential 

is determined by a combination of temperature and humidity providing a long active growing season for decay fungi 

and termites. The Harrison National Experimental Forest 

(HEF) in Mississippi has a high decay hazard potential and 

has served as the primary research site for field performance 

tests since 1938. Field plots contain many treated stakes 

partially buried in the ground in a grid pattern. Each stake 

is periodically removed and individually inspected for signs 

of decay or termite damage. A standardized rating system 

is used to rate each stake until it fails from fungal decay 

or termite damage. For a particular preservative treatment, 

replicate stakes (up to 20) are installed to account for natural 

variability by microorganisms present in a particular field 

plot. The 02 Report (Comparison of Wood Preservatives in 

Stake Tests: 2011 Progress Report), summarizing the results 

from field stake plots is published approximately once each 

decade (Woodward and others 2011). Stake plot tests are 

considered to be realistic tests of treated wood in a realistic 

application. For example, Southern Pine posts treated with 

pentachlorophenol in oil, creosote, and copper naphthenate 

in oil that were installed in 1949 in the HEF were still performing well in 2005 and have a calculated life span exceeding 60 years (Freeman and others 2005).

Creosote and pentachlorophenol were once the main preservative treatments of wood until the 1950s, when copper 

formulations were introduced. While creosote and pentachlorophenol continue to be the preservative of choice for 

specific applications such as utility poles, cross-arms, railway sleepers, and marine pilings, copper-based formulations 

have been used to treat a majority of the wood used in the 

United States since the early 1970s (Lebow and others 2004; 

Lebow 2010), resulting in numerous field-plot tests in the 

HEF to evaluate those formulations.

The first documented incident of preservative tolerance by 

Poria luteofibrata Baxter (synonymous with Poria radiculosa Peck) was in 1952 in an official report written by George 

H. Hepting, Division of Forest Pathology in Ashville, North 

Carolina. P. luteofibrata was first described by Baxter from 

a Northern Florida collection in 1938 and later shown to 

exactly duplicate every detail of Peck’s description of 

P. radiculosa. In the 1952 report, creosoted poles were prematurely failing at the ground line in the Piedmont region 

in as few as 7 years. Hepting had noted for some years “a 

fungus that produced yellow strands in and on the decayed 

wood was very consistently associated with these decayed 

poles.” The fungus that caused 22% weight loss in creosotetreated wood blocks in laboratory tests was identified from a 

mature sporophore by Josiah Lowe as P. radiculosa in 1950. 

In 1946, when Lowe’s manual on Poria was published, 

P. radiculosa was considered to be a rare species (Lowe 

1946); by 1950 it was reported to be a widely distributed 

and fairly common species in the Eastern United States 

(Hepting 1952).

In 1965, a report by the U.S. Department of Agriculture 

identified 1,464 fungi isolated from decayed wood items to 

species (Duncan and Lombard 1965). Observations were 

compiled regarding associations with type of wood product, 

wood type (softwood or hardwood), decay types (brown-rot 

or white-rot), geographical location by region, and treatment 

type (if the product had been treated with a preservative). Of 

the 152 different species identified, P. radiculosa was one 

of the 10 most prevalent fungi, occurring 34 times on softwoods primarily in the southern United States. Twenty-four 

percent (8 of 34) of the specimens were isolated from poles 

treated with creosote, zinc chloride, copper naphthenate, and 

pentachlorophenol. Seventy-four percent (25 of 34) were 

isolated from experimental stakes treated with chromate 

zinc chloride, chromate copper zinc chloride, chromate zinc 

arsenate, copper chromate, copper naphthenate, creosote, 

fluor-chrome-dinitrophenol or zinc chloride in ground 

contact.

In 1971, stakes in a field plot in the HEF treated with copper 

chromate arsenic (CCA) and acid copper chromate (ACC) 

began to fail prematurely. Decay by a fungus with bright 

yellow mycelium and thick hyphal cords was noted on one 

ACC-treated stake that catastrophically failed within the 

first 12 months of exposure (unpublished field data, Lee 

Gjovik, Forest Products Technologist (retired), USDA Forest Service, Forest Products Laboratory, 11/12/1972). The 
General Technical Report FPL–GTR–204

2

failed stake was brought to the FPL for culturing. Three isolates were cultured from the thick yellow hyphal strands by 

Wallace Eslyn, Research Plant Pathologist at FPL, and microscopically identified using morphological and chemical 

characteristics by Francis Lombard, Mycologist at FPL. All 

three isolates, initially identified as Meruliporia incrassata, 

were given the designation of ME which stood for “Madison 

strain isolated by Eslyn.” These isolates were presumed to 

be highly tolerant of copper and chromium but not arsenic. 

Subsequently, the isolate designations were changed to 

TFFH 294, TFFH 296, and TFFH 128. TFFH is an acronym 

for “The fungus from hell” because of its very high tolerance to wood-preserving chemicals. Major research results 

involving TFFH 294 will be discussed chronologically by 

topic with pertinent references after each section, followed 

by current and past nomenclature.

Historical References

Duncan, C.G. and Lombard, F.F. 1965. Fungi associated 

with principal decays in wood products in the United States. 

U.S. Forest Service Research Paper WO-4, Department of 

Agriculture, Washington, D.C. 31 p.

Freeman, M.H., Crawford, D., Lebow, P., and Brient, J.A. 

2005. A comparison of wood preservatives in posts in 

southern Mississippi: results from a half-decade of testing. 

Proceedings American Wood Protection Association, 

101: 136–143.

Hepting, G.H. 1952. Poria radiculosa, a fungus that will rot 

creosoted wood. Official Report, Division of Forest Pathology, Bureau of Plant Industry, Soils, and Agricultural Engineering, Ashville, NC.

Lebow, S.T. 2010. Chapter 15. In: Wood Handbook–Wood 

as an engineering material. General Technical Reoprt FPL–

GTR–190. Madison, WI: U.S. Department of Agriculture, 

Forest Service, Forest Products Laboratory. 508 p.

Lebow, S.T, Winandy, J., and Bender, D. 2004. Treated 

wood in transition: a look at CCA and the candidates to 

replace it. Wood Design Focus. (Summer 2004): 3–8.

Lowe, J.L. 1946. The Polyporaceae of New York State. The 

Genus Poria. The New York State College of Forestry Technical Publ. 65. 91 p.

Woodward, Bessie M.; Hatfield, Cherilyn A.; Lebow, 

Stan T. 2011. Comparison of wood preservatives in stake 

tests: 2011 progress report. Research Note FPL–RN–0327. 

Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 120 p.

Bioremediation (1996 to 2006) 

No published research could be located for these isolates 

until 1996 when Terry Highley and Barbara Illman published that M. incrassata TFFH 294 caused 40.2% weight 

loss in CCA-treated Southern Pine sapwood in a laboratory 

soil block test (Illman and Highley 1996; Illman and others 

1996). These were the first in a series of reports on screening of fungal isolates for preservative tolerance that culminated in a patented method for bioremediation of CCAtreated waste wood (Illman and others 2000; 2002; 2005; 

Illman and Yang 2006; Yang and Illman 1999). In screening 

studies, TFFH 294 did not show tolerance to creosote or 

pentachlorophenol.

Bioremediation References

Illman, B.L.; Highley, T.L. 1996. Fungal degradation of 

wood treated with metal-based preservatives: 1. Fungal 

tolerance. IRG/WP 96–10163. Stockholm, Sweden: International Research Group on Wood Preservation. 8 p.

Illman, B.L.; Baht, S.; Highley, T.L. 1996. Fungal degradation of wood treated with metal-based preservatives: 2. 

Redox states of chromium. IRG/WP 96–10164. Stockholm, 

Sweden: International Research Group on Wood Preservation. 10 p.

Illman, B.L.; Yang, V.W. 2006. Bioremediation and degradation of CCA-treated wood waste. In: Townsend, T.G.; SoloGabriele, H., eds. Chapter 23, Environmental impacts of 

treated wood. Boca Raton, FL: Taylor & Francis: 413–426. 

Illman, B.L.; Yang, V.W.; Ferge, L.A. 2000. Bioprocessing preservative-treated waste wood. IRG/WP 00–50145. 

Stockholm, Sweden: International Research Group on Wood 

Preservation. 11 p.

Illman, B.L.; Yang, V.W.; Ferge, L.A., inventors. 2002 

(March 31). Fungal strains for degradation and bioremediation of CCA-treated wood. U.S. Patent 6,495,134.

Illman, B.L.; Yang, V.W.; Ferge, L.A., inventors. 2005 

(December 6). Fungal degradation and bioremediation 

system for CCA-treated wood. U.S. Patent 6,972,169.

Yang, V.W.; Illman, B.L. 1999. Optimum growth conditions 

for the metal-tolerant wood decay fungus, Meruliporia incrassata TFFH 294. IRG/WP 99–50142. Stockholm, Sweden: International Research Group on Wood Preservation. 

9 p.

Role of Oxalic Acid Production in 

Copper Tolerance (1999 to present)

Copper has been the major biocide used in the formulation 

of new preservatives to inhibit fungal decay; however, the 

ability of copper-tolerant decay fungi to circumvent copper toxicity has been a concern for decades. As long ago 

as 1931, Rabanus hypothesized that oxalate production in 

decay fungi may be linked to copper tolerance (Rabanus 

1931). Copper oxalate crystal formation in decayed wood 

was documented in the literature (Murphy and Levy, 1983; 

Sutter and others, 1983). The presumption was that oxalic 

acid (OA) precipitates copper into copper oxalate crystals 

(insoluble form) and renders the copper ion inert. They 
Chronicles of Fibroporia radiculosa (= Antrodia radiculosa) TFFH 294

3

also hypothesized that a number of diverse factors such 

as growth rate, pH, OA production, and decay capacity 

all contribute to copper tolerance. Subsequently, brownrot wood decay fungi in the genus Poria (Pers. ex Gray), 

and other genera related to Poria, such as Serpula [(Pers.) 

Gray], Antrodia (D.C.: Fr.) Ryv., and Wolfiporia (Schw syn. 

Poria cocos), were shown to be copper tolerant (Davidson

and Campbell 1954; Collet 1992; Leithoff and others 1995; 

Schmidt and Moreth 1996; Tsunoda and others 1997). 

Rodney DeGroot and Bessie Woodward studied copper 

tolerance in Wolfiporia cocos and concluded that 

W. cocos has the ability to immobilize copper by precipitating copper oxalate (DeGroot and Woodward 1999). This 

study was expanded by Carol Clausen and Frederick Green, 

who reported considerable intra-species copper tolerance 

variability in the W. cocos isolates that they evaluated. They 

also found no statistical relationship between the amount of 

oxalic acid production in liquid culture or wood and copper 

tolerance in that group of W. cocos isolates and OA production did not seem to be the sole controlling factor for copper 

tolerance in this study (Clausen and others 2000). Green and 

Clausen continued to evaluate the ubiquity of copper tolerance in other aggressive brown-rot isolates including TFFH 

(Green and Clausen 2001). They showed that there are 

varying degrees of copper tolerance in brown-rot isolates 

from seven genera representing some of the most aggressive 

brown-rot fungi including Antrodia, Wolfiporia, Tyromyces, 

Postia, Serpula, Meruliporia, and Coniophora, with species 

of Gloeophyllum being the only recognized copper-sensitive 

brown-rot fungi. Following the finding that high levels of 

oxalic acid (OA) were a dominant characteristic in coppertolerant brown-rot basidiomycetes, the mechanism of copper 

tolerance became a topic of research interest. 

Throughout their studies, Green and Clausen (2001, 2005), 

and Clausen and Green (2003) consistently linked high levels of OA production to copper tolerance in these genera. 

Exposure of copper-tolerant fungi to low concentrations of 

ammoniacal copper citrate accentuated OA production. Up 

to 17 times more OA was produced in ammoniacal copper 

citrate-treated wood than untreated wood by the test fungi 

from these genera with Antrodia repeatedly producing the 

most OA. At week 4, ammoniacal copper citrate stimulated 

66% to 93% more OA production in treated wood than the 

untreated controls. Additionally, tolerance to copper was 

laboratory tested on wood treated with several different 

copper-based wood preservatives including those that are 

arsenic-free. TFFH 294 was included for comparison in two 

additional studies on the role of OA production. First, the 

role of OA production on tolerance of Tyromyces palustris

TYP 6137 to the copper-free wood preservative, naphthaloylhydroxylamine (NHA) was evaluated (Arango and others 2006). Unlike T. palustris, TFFH 294 was not tolerant 

of NHA-supplemented malt agar and Arango and others 

concluded that NHA tolerance of T. palustris was not mediated by overproduction of OA. Second, the effect of calcium 

chloride on growth and decay of 12 strains of Serpula lacrymans was evaluated by Hastrup and others (2006). In this 

study, rate of decay was estimated in Southern Pine blocks 

treated with ammoniacal copper citrate followed by calcium 

chloride (CaCl2). Decay by S. lacrymans was found to be 

significantly inhibited by treatment with CaCl2 in the presence of copper, suggesting that CaCl2 was functioning as 

an OA sink, leaving Cu ions in the solution to act as a fungicide. However, TFFH 294 and Postia placenta displayed 

notable wood decay despite CaCl2 treatment. 

Oxalic Acid References 

Arango, R.; Clausen, C.A.; Green, F., III. 2006. The role of 

oxalic acid in tolerance to N’N-napthaloylhydroxylamine in 

Tyromyces palustris. IRG/WP 06–10584. Stockholm, Sweden: International Research Group on Wood Protection. 8 p.

Clausen, C.A.; Green, F., III. 2003. Oxalic acid overproduction by copper-tolerant brown-rot basidiomycetes on southern yellow pine treated with copper-based preservatives. International Biodeterioration & Biodegradation. 51: 139–144. 

Clausen, C.A.; Green, F., III; Woodward, B.M.; Evans, J.W.; 

DeGroot, R.C. 2000. Correlation between oxalic acid production and copper tolerance in Wolfiporia cocos. International Biodeterioration & Biodegradation. 46: 69–76.

Collet, O. 1992. Comparative tolerance of the brown-rot 

fungus Antrodia vaillantii (DC.:Fr) Ryv. isolates to copper. 

Holzforschung. 46: 293–298.

Davidson, R.W.; Campbell, W.S. 1954. Poria cocos, a 

widely distributed wood-rotting fungus. Mycologia. 46: 

234–237.

DeGroot, R.C.; Woodward, B. 1999. Using copper-tolerant 

fungi to biodegrade wood treated with copper based preservatives. International Biodeterioration & Biodegradation. 

44: 17–27.

Green, F., III; Clausen, C.A. 2001. Oxalic acid production 

of fifteen brown-rot fungi in copper citrate-treated southern 

yellow pine. IRG/WP 01–10388. Stockholm, Sweden: International Research Group on Wood Preservation. 10 p.

Green, F.; Clausen, C.A. 2005. Copper tolerance of brownrot fungi: oxalic acid production in southern pine treated 

with arsenic-free preservatives. International Biodeterioration & Biodegradation. 56: 75–79.

Hastrup, A.C.S.; Jensen, B.; Clausen, C.A.; Green, F., III. 

2006. The effect of CaCl2 on growth rate, wood decay and 

oxalic acid accumulation in Serpula lacrymans and related 

brown-rot fungi. Holzforschung. 60: 339–345.

Leithoff, H.; Stephan, H.L.; Lenz, M.T.; Peek, R.-D. 1995. 

Growth of the copper tolerant brown-rot fungus Antrodia 

vaillantii on different substrates. IRG/WP 95–10121. Stockholm, Sweden: International Research Group on Wood 

Preservation. 11 p.
General Technical Report FPL–GTR–204

4

Murphy, R.J.; Levy, J.F. 1983. Production of copper oxalate 

by some copper tolerant fungi. Transactions of the British 

Mycological Society. 81: 165–168.

Rabanus, A. 1931. Die toximetrische prunfung von holzkonservierungsmitteln. [Toximetric testing of wood preservatives]. In: Proceedings, American Wood Preservers’ Association. (1933): 34–43. Angewante Botanik. 13: 352–371. 

In German.

Schmidt, O.; Moreth, U. 1996. Biological characterization 

of Poria indoor brown-rot fungi. Holzforschung. 

50: 105–110.

Sutter, H.P.; Jones, E.B.G.; Walchli, O. 1983. The mechanism of copper tolerance in Poria placenta (Fr.) Cke. and 

Poria vaillantii (Pers.) Fr. Material und Organismen. 

18: 241–262.

Tsunoda, K.; Nagashima, K.; Takahashi, M. 1997. High 

tolerance of wood-destroying fungi to copper-based fungicides. Material und Organismen. 31(1): 31–44.

Genetic Analysis (2005 to 2011)

In 2005, Anne-Christine Hastrup, University of Copenhagen, conducted phylogenetic analyses on S. lacrymans, 

an economically important dry-rot fungus in Europe, and 

several North American fungi, including TFFH 294, which 

was then called M. incrassata. Following DNA extraction 

and polymerase chain reaction (PCR), the ribosomal DeoxyriboNucleic Acid–Internal Transcribed Spacer (rDNA-ITS) 

sequence was compared to known sequences deposited in 

GenBank. GenBank, the National Institutes of Health genetic sequence database, is a collection of all publicly available DNA sequences. Hastrup (2005) reported that TFFH 

294 most closely aligned with Antrodia vaillantii and not 

M. incrassata. Simultaneously, Dan Lindner, Research Plant 

Pathologist, USDA Forest Service Northern Research Station, sequenced the isolate and based on the ITS sequence, 

TFFH 294 was placed in the Antrodia clade. Dr. Lindner felt 

the ITS sequence information in GenBank was not specific 

enough to confidently name the species in 2006 (personal 

communication to Clausen, 2006). In 2010, Juliet Tang, 

doctoral student at Mississippi State University, sequenced 

the genome of TFFH 294 (Tang and others 2010). She also 

amplified, cloned, and sequenced the rDNA–ITS region to 

confirm the identity of the isolate. This time, however, the 

GenBank database contained many more entries and the 

sequenced DNA aligned to two different Fibroporia radiculosa (=Antrodia radiculosa) voucher specimens (Tang, doctoral student, Mississippi State University, Starkville, Mississippi, personal communication to Clausen, 2010), thereby 

confirming that the fungus was, in fact A. radiculosa. That 

finding was not surprising since other A. radiculosa isolates 

are the most copper-tolerant brown-rot fungi and produce 

the highest amount of oxalic acid compared with other 

brown-rot fungi tested to date.

Genetics References

Hastrup, A.C.S. 2005. Serpula lacrymans—the dry-rot 

fungus: copper tolerance, calcium demand, oxalic acid production and phylogenetic studies. Copenhagen, Denmark: 

University of Copenhagen. 127 p. M.S. thesis in Biology.

Tang, J.D.; Perkins, A.; Sonstegard, T.; Burgess, S.; Diehl, 

S.V. 2010. A genomic sequencing approach to study wood 

decay and copper tolerance in the brown-rot fungus, Antrodia radiculosa. IRG/WP 10–10720. Stockholm, Sweden. 

International Research Group on Wood Protection. 16 p.

Metal Tolerance (2009)

While evaluating nanometals as potential preservatives, 

Nami Kartal of Istanbul University and scientists at FPL 

confirmed that A. radiculosa TFFH 294 was also resistant 

to nanozinc, nanocopper, and a commercial combination of 

nanozinc and silver (Kartal and others 2009; Clausen and 

others 2009). Recall that in 1950, the original concern about 

P. radiculosa Peck was tolerance to creosote (22% weight 

loss). However, tolerance to creosote has not been reported 

for isolate TFFH 294. In addition to copper, zinc, and silver, 

TFFH 294 is known to be tolerant of chromium and arsenic 

present in CCA-treated wood (40.2% weight loss). 

Metal Tolerance References

Clausen, C.A.; Yang, V.W.; Arango, R.A.; Green, F., III. 

2009. Feasibility of nanozinc oxide as a wood preservative. 

In: Proceedings, American Wood Protection Association. 

105: 255–260.

Kartal, S.N.; Green, F., III; Clausen, C.A. 2009. Do the 

unique properties of nanometals affect leachability or efficacy against fungi and termites? International Biodeterioration 

& Biodegradation. 63: 490–495.

Future Research: Mechanism of 

Copper Tolerance (2010 to Present)

The question that has remained unanswered is what mechanistic role, if any, does the accumulation of OA coupled with 

copper oxalate crystal formation play in copper tolerance of 

basidiomycetes? Understanding the biosynthesis of oxalic 

acid will lead to a better understanding of the coppertolerance mechanism used by isolates of F. radiculosa to 

overcome copper-based wood preservatives. Munir and others (2001) investigated the role of OA biosynthesis in the 

copper-tolerant fungus, Tyromyces palustris (=Fomitopsis 

palustris), and linked it to both the tricarboxylic acid (TCA) 

and the glyoxylate (GLOX) pathways. Their work discovered that there are two major oxalate producing enzymes: 

glyoxylate dehydrogenase and oxaloacetase, with isocitrate 

lyase acting as a vital enzyme involved in the production of 

OA. To understand the mechanism of copper tolerance, production of key enzymes from the TCA and GLOX pathways 

by F. radiculosa TFFH 294 will be assayed from untreated 
Chronicles of Fibroporia radiculosa (= Antrodia radiculosa) TFFH 294

5

and copper-treated wood in an attempt to establish the pathway involved in OA production for this organism (Jenkins 

and others 2012). Using functional and comparative genomics, Tang and others (2010, 2011) hope to identify novel 

genes that regulate wood decay under different environmental conditions. Gene expression levels will be compared for 

decay on untreated and copper-treated wood to determine if 

expression is enhanced by the presence of copper (Jenkins 

and others 2012). Finally, gene expression will be correlated 

to enzymes responsible for the oxalic acid production 

(Jenkins and others 2012). Unraveling the mechanism of 

copper tolerance through genetic expression and enzyme 

production will enable development of novel targeted biocides to circumvent preservative-tolerance in Antrodia and 

other brown-rot genera. 

Mechanism References

Jenkins, K.M.; Diehl S.V.; Clausen, C.A.; Green, F., III. In 

press. Enzymatic mechanism of oxalate production in the 

TCA and glyoxylate using various isolates of Antrodia radiculosa. In: Proceedings, American Wood Protection 

Association. Birmingham, AL: Vol. 107. 

Munir, E.; Yoon, J.J.; Tokimatsu, T.; Hattori, T.; Shimada, 

M. 2001. A physiological role for oxalic acid biosynthesis 

in the wood-rotting basidiomycete Fomitopsis palustris. 

In: Proceedings, National Academy of Sciences. PNAS 98 

(20): 11126–11130.

Tang, J.D.; Jenkins, K.; Parker, L.; Diehl, S.V. 2010. Towards understanding the biology of wood decay. IRG/WP 

10–10739. Stockholm, Sweden. International Research 

Group on Wood Protection. 5 p.

Tang, J.D.; Perkins, A.; Diehl, S.V. 2011. Gene expression 

analysis of a copper-tolerant brown-rot fungus on MCQtreated wood. IRG/WP 11–10748. Stockholm, Sweden. 

International Research Group on Wood Protection. 18 p.

Nomenclature (1921 to Present)

Whereas mycological taxonomic nomenclature remains a 

dynamic field, genetic analysis based on nuclear rDNA–ITS 

sequences support returning Antrodia radiculosa (Peck) to 

the name Fibroporia radiculosa (Peck), while separating 

Antrodia into a separate genus more closely related to other 

genera of brown-rot fungi such as Fomitopsis P. Karst., 

Daedalea Pers., Gloeophyllum P. Karst., and Oligoporus

Bref (Bernicchia and others 2010). Below is the taxonomic 

history of the nomenclature for Fibroporia radiculosa described by Gilbertson and Ryvarden (1986) and documented 

in the Index Fungorum database (www.indexfungorum.org

2011). Index Fungorum, in partnership with CBS (Centraalbureau voor Schimmelcultures), CABI (Centre for Agriculture and Biosciences International) and Landcare Research, 

is the internationally recognized online database for fungal 

nomenclature. Based on current literature and entries in 

Index Fungorum, the current name for TFFH 294 is 

F. radiculosa (Peck), which is synonymous with A. radiculosa (Peck) Gilb. & Ryvarden and P. radiculosa (Peck) 

amongst others. 

Current name:

Fibroporia radiculosa (Peck) Parmasto. 

Conspectus Systematis Corticiacearum 

(Tartu): 177.

Synonymy:

Antrodia radiculosa (Peck) Gilb. & Ryvarden. 

1985. Mycotaxon 22(2): 363.

Fibuloporia radiculosa (Peck) Parmasto. 1963. 

Issled. Prirody Dal’nego Rostoka: 257.

Polyporus radiculosus Peck. 1887. Annual Report 

New York State Museum. 40: 54.

Poria flavida Murrill. 1921. Mycologia 13(3): 174.

Poria radiculosa (Peck) Sacc. 1888. Syll. Fung. 

(Abellini) 6: 314. 

Poria subradiculosa Murrill. 1921. Mycologia 

13(3): 175.

Nomenclature References

Bernicchia, A.; Perez Gorjon, S.; Vampola, P.; Ryvarden, 

L. Prodi, A. 2010. A phylogenetic analysis of Antrodia s.l.

based on nrDNA ITS sequences, with emphasis on rhizomorphic European species. Mycological Progress. DOI 

10.1007/s11557–010–0732–z. 

Gilbertson, R.L.; Ryvarden, L. 1986. In: North American 

Polypores, Volume 1: Abortiporus-Lindtneria, Fungiflora 

A/S. Oslo, Norway: 140–141. [Out of print]. 

Index Fungorum 2011. www.indexfungorum.org.