Cite as: Trappe, J. M. The hunted: commercially attractive native to North America. In Les champignons forestiers comestibles à potentiel commercial. ÉDITEUR. Biopterre, ACCHF, Université Laval, CEF, RNC, 30 novembre et 1er décembre 2009. pp. 97-102 Available at http://194.254.27.242/photo/10.pdf 11/29/2012.

The hunted: commercially attractive truffles native to North America

James M. Trappe

Department of Forest Ecosystems and Society Oregon State University Corvallis, Oregon, USA 97331-5752

INTRODUCTION

A few herbarium packets of North lyonii Butters) from Texas and the American truffles have annotations yellow furrowed , Tuber hinting at sale of specimens harvested by canaliculatum Gilkey, from the Italian immigrants to restaurants in New Northeastern USA and York City in the early 20th century, but pronounced both to be “exquisite” the first recorded commercial harvesting (James Beard, personal communication). began with the founding of the North The pecan truffle has entered commerce American Trufflling Society (NATS) in at least regionally in Georgia, but I am Oregon in 1978 (Rawlinson et al.1995). not aware of any commercial harvest of Members not only sought native truffles T. canaliculatum. Finally, localized with great enthusiasm but also tried all populations of the giant (Imaia species found in various culinary gigantea) have been found in the combinations with other foods. Early on, Appalachians of North Carolina and the Oregon white truffle (Tuber Tennessee, and limited commercial gibbosum Harkn.) gained a reputation as harvesting has begun (Kovacs et al. being particularly desirable. Other 2008). species also achieved positive reputations in the region: the Oregon Wild truffle harvesting in North black truffle ( carthusianum America is an unregulated endeavor, and (Tul.) Paol. and the brown neither all harvesters nor all chefs are truffle (Kalapuya brunnea M. Trappe, expert identifiers of truffle species. I Trappe & Bonito, formerly termed the have been asked several times to identify Oregon brown truffle under the specimens purchased by restaurants, and provisional name Leucangium brunneum on some occasions the purported Oregon nom. ined). These and the many other white truffles were none of the species but less desirable genera and species in mentioned above and generally had little the region are discussed by M. Trappe et fragrance or an unattractive one. al. (2007, 2010) and J. Trappe et al. The earliest establishment of (2009). truffières of the European black truffle (Tuber melanosporum Vittad.) in North Meanwhile, the celebrated chef, America is not documented, but the first James Beard, had opportunity to one to produce truffles appears to be that experience the pecan truffle (Tuber established in 1982 by Bill Griner and his associates near Laytonville, only infrequent inflated cells. California. Its first truffle production Both types differed from all other was in 1987 (Rigdon, 2004). Since then, known Tuber spp. by having a sparse many additional truffières have been surface pubescence of emergent hyphal established along the West Coast from tips with a beaded appearance derived British Columbia through northern from swellings scattered along the California, in Texas, Tennessee, North hyphal wall. Together, the presumed two Carolina, and probably other states of species occurred from the San Francisco the eastern seaboard. The most Bay region north to Vancouver Island, productive truffière so far documented British Columbia. DNA analysis of for North America is Tennessee Truffles, specimens from an array of geographic which produced about 90 kg of Tuber and seasonal collections then revealed a melanosporum in the 2008-2009 season complex of four closely related but well (Michaels 2010). A good review of the defined species (Bonito et al. 2010): truffle industry in Oregon by Pilz et al. Tuber gibbosum, T. bellisporum Bonito (2009) covers both native truffles and & Trappe, T. castellanoi Bonito & black truffle truffières. I have not seen Trappe, and T. oregonense Trappe, an equivalent review for other parts of Bonito & P. Rawlinson. the continent. Morphologically and seasonally they With this brief background, the rest overlap to some degree, so microscopy of this paper outlines what is known is needed to accurately identify species. about the North American truffle species All are generally equivalent in aroma currently produced in commerce or and flavor when fully mature, so they having good potential for that. need not be distinguished from one another for marketing purposes. Bonito et al. (2010) fully describe each species. THE NORTH AMERICAN Oregon white truffles are strongly COMMERCIALLY HARVESTED pungent-garlicky-spicy when mature. TRUFFLES They can be used in much the same way as the Italian white truffle (Tuber THE TUBER GIBBOSUM COMPLEX magnatum Vittad.). Numerous culinary (OREGON WHITE TRUFFLES) uses of Oregon white truffles are described by Evans and Evans (1987). Until recent decades, T. gibbosum The distributions of Oregon white was regarded as a single species truffles differ somewhat between occurring from northern California species, though all tend to be most through western Oregon (Gilkey 1954). common in western Oregon (Bonito et Numerous collections by NATS al. 2010). All occur in southwest members, however, extend the range to Washington State south to northern British Columbia and indicated that two California. T. gibbosum goes the farthest similar related species are involved. T. north to southern Vancouver Island. T. gibbosum in the strict sense was castellanoi reaches the farthest south collected mostly in winter through with an outlier collection from the spring and was termed the “spring northern Sierra Nevada mountains. T. Oregon white truffle.” It has ellipsoid to oregonense and T. bellisporum have the broadly ellipsoid and an outer smallest distributions, T. oregonense peridium composed of several tiers of from southern Puget Sound in inflated cells. The other, occurring Washington State to southwestern mostly in late autumn into winter, was Oregon and T. bellisporum shifted south, designated the “autumn Oregon white from far southwestern Washington into truffle” characterized as containing northern California. narrowly ellipsoid spores and an outer peridium of interwoven hyphae with Habitat-wise, all four species abound in mesic habitats bearing young full maturity becomes wine-like or plantations to small sawtimber forests of penetrating. Cooking volatilizes its fruity Douglas-fir (Pseudotsuga menziesii) at aromas, so it is best used raw in salads or relatively low elevations (≤ 600 m) west as a complement to cheeses. of the Cascade and Sierra Nevada. Oregon black truffles have been Christmas tree plantations are reported from the Willamette Valley and particularly productive producers, so the its surrounding foothills of northwestern potential of a dual, truffle-Christmas tree Oregon to coastal forests, then north crop is substantial and merits through western Washington to developmental research. In addition to southwestern British Columbia. It the most common host tree, Douglas-fir, appears to be associated with Douglas- Abies spp. in pure plantations or in fir, particularly in stands of small to forests are also recorded as occasional large poles. In habitats where they occur, hosts. Oregon black truffles can abound and reach good size, often several fruiting LEUCANGIUM CARTHUSIANUM (OREGON together in pockets. BLACK TRUFFLES) KALAPUYA BRUNNEA (OREGON BROWN It may seem strange that Leucangium TRUFFLES) carthusianum (Tul. & C. Tul.) Paol., originally described from eastern France, The newly described has become known in North America as Kalapuya is named for the Kalapuya the Oregon black truffle. The DNA of tribe of native Americans, because its western Oregon representatives differs range roughly coincides with the little from that of European ones (M. ancestral homeland of the . It Trappe et al. 2010). The reason for this is a relatively large, brown, warty truffle huge disjunction in occurrence of a with an interior similar to that of Oregon single species has not been explained, black truffles. Originally, its but it seems to be more common in macroscopic similarity to Leucangium Pacific northwestern USA and caused it to be provisionally named southwestern Canada than in Europe. Leucangium brunneum, although its The surface of Oregon black truffles spores are ellipsoid rather than eye- is black to brownish black and shaped. roughened to warty. The interior is whitish, at maturity consisting of DNA analysis showed that it irregular, gray to olive gray, belongs in the along with bearing pockets embedded in whitish Leucangium but merits a separate genus tissue. Its spores are distinctive, up to 90 (M. Trappe et al. 2010). Like μm long, smooth and shaped rather like Leucangium, it does not look anything a human eye. At maturity when the like a morel. M. Trappe et al. (2007) spores are seen through the microscope describe and illustrate Kalapuya (as at this stage, one gets the sensation that Leucangium brunneum). eyes in the slide mount are gazing back Kalapuya brunnea M. Trappe, at one. The Oregon black truffle is Trappe & Bonito ranges from described and illustrated by M. Trappe et northwestern California to northwestern al. (2007). The species is in the Oregon at elevations up to about 500 m. Morchellaceae as evidenced by DNA It has not been found north of the analysis (M. Trappe et al. (2010), Columbia River. although by morphology alone it is difficult to suppose a relationship to The aroma of K. brunnea is garlicky, morels. weak in early maturity and becoming stronger as it matures. It can be diced In youth, Oregon black truffles have and added raw to pasta or other dishes a fruity, pineapple-like aroma which at for flavor and texture and for making garlic butter. Elliott. It seemed to be well matured and had a nice, fruity red wine aroma. This species occurs in Douglas-fir The giant Imaia occurs in autumn stands up to about 50 yrs old in mesic amongst mosses or in the upper 10-15 habitats. cm of humus of deciduous or mixed deciduous-conifer forests. It has been IMAIA GIGANTEA (GIANT IMAIA) commercially harvested for sale to restaurants by use of trained dogs but Originally found in Japan in the only on a very small scale. 1930’s, this species was named gigantea by the renowned Japanese THE TUBER LYONII COMPLEX (PECAN OR mycologist Sanshi Imai. A few years TEXAS TRUFFLE) later it turned up in Pennsylvania (Trappe and Sundberg 1977) and since Once thought to range from Ontario, has been found over much of the Canada south into northeastern Mexico Appalachian Mountains of eastern USA. and from the Great Plains to the East It does not fit comfortably in Terfezia: Coast (J. Trappe et al. 1996, M. Trappe all other species of that genus occur in et al. 2007). T. lyonii Butters may rather arid to semi-arid habitats, and T. be a complex of two or more closely gigantea has much larger spores with a related species (G. Bonito, unpublished much more complex spore data). Molecular studies are needed to ornamentation that the other Terfezia sort this out, so meanwhile we will refer species. Now, phylogenetic studies show to the “T. lyonii complex” or the pecan that it needs a new genus, which has truffle with emphasis on the area where been named Imaia in honor ot Dr. Imai, they are harvested, the Gulf Coast states. its original finder and describer (Kovács Pecan truffles are described and et al. 2008). illustrated by J. Trappe et al. (1996) and M. Trappe et al. (2007). They are of As is the case with Leucangium medium size, with a reddish to orange carthusianum, the DNA of the two brown, smooth surface with roughened known populations of I. gigantea differs furrows. The spores are spiny, with the little, even though they are an ocean and spines connected by low lines at the a continent apart (Kovács et al. 2008). base. At present we can only speculate how this happened. In North America it is The aroma of these truffles has recorded in the Applachians from components of garlic, spices, cheese, and Pennsylvania south to North Carolina indefinable essences at full maturity. and Tennessee. The phylogenetic These fragrances may volatilize during evidence places it in the Morchellaceae cooking, so the truffles are best used along with Kalapuya and Leucangium uncooked but may be added to hot (Kovács et al. 2008, M. Trappe et al. dishes just before serving. 2010). Pecan and oak trees are the usual The ascomata can be large (Imai hosts, often in rather dry habitats. chose the name gigantea because he had However, irrigated pecan orchards with one specimen 10 x 15 cm) with a dark, clayey soils appear to be the most cracked and warty, brown to orange productive sites, although one must be brown surface and an interior of brown careful not to collect where pesticides pockets of spores nested in a whitish have been applied during the fruiting tissue. It is described and illustrated in season. Local restaurants buy them in detail by M. Trappe et al. (2007) and Georgia to enhance their menus. Minor Kovács et al. (2008). Its aroma has been (2003) gives a detailed account of the described as “rich, fragrant and fruity.” I harvest and sale of pecan truffles in tried a fresh specimen supplied by Todd Georgia. many unripe truffles which have not developed their aromas, thus producing TUBER CANALICULATUM (YELLOW- an inferior product that lowers the price. FURROWED TRUFFLE) These issues need to be resolved for the good of the truffle industry. Tuber canaliculatum Gilkey is a striking, robust truffle that with a warty, LITERATURE CITED brown to cinnamon surface that tends to have deep furrows and patches lined Bonito G, Trappe JM, Rawlinson P. with yellow mycelium. Its interior is 2010. Species diversity within the very firm and dark brown with white, Tuber gibbosum complex, the meandering veins at maturity. Its aroma “Oregon white truffles.” Mycologia is strongly pungent but pleasing. Chef (in press). James Beard pronounced it “exquisite.” As is true of most truffles, it’s fragrance Evans F, Evans K. 1987. The cookbook is driven off by cooking, so it should be of North American truffles. North added raw to hot dishes just before American Truffling Society, serving (M. Trappe et al. 2007). Corvallis, Oregon.

The yellow-furrowed truffle occurs Gilkey HM. 1954. Tuberales. North from southeastern Canada south to North American Flora Series 2, Part 1:1-56. Carolina and Tennessee in mixed conifer-hardwood forests or pure pine Guevara G, Bonito G, Cázares E, stands (M. Trappe et al. 2007). Although Rodriguez J, Vilgalys R, Trappe JM. it would seem to have good commercial 2008. Tuber regimontanum, new potential, I have not found any record of species of truffle from Mexico. commercial harvest. Revista Mexicana de Micologia 26: 17-20. DISCUSSION Kovács GM, Trappe JM, Alsheikh AM, The species outlined above are not Bóka K, Elliott TF. 2008. Imaia, a the only ones with possible commercial new genus to accommodate Terfezia potential, but they represent the ones gigantea. Mycologia 100: 950-959. currently of greatest interest. For example, a black truffle closely related Michaels T. 2010. Tennessee Truffles. to Tuber melanosporum of Europe has http/www.tennesseetruffle.com. recently been described from near Monterrey, Mexico (Guevara et al. Minor, E. 2003. A , a delicacy: 2008). Other species, including Georgia sniffs out its truffles. basidiomycete genera such as www.bio.net/hypermail/agroforestry/ Melanogaster and Rhizopogon, have 2003-February/017537.html found their way into culinary use but so . far not into the North American Pilz D, Lefevre C, Scott L. 2008. Oregon commercial markets (Evans and Evans culinary truffles—an emergent 1987, M. Trappe et al. 2007). Still others industry for Forestry and Agriculture. likely remain to be discovered. www.oregontruffles.org.

A serious issue, both environmentally Rigdon JE. 1994. Californians claim to and economically, involves the large- unearth secret of raising truffles. The scale hunting of truffles by raking rather Wall Street Journal, 25 March 1994. than by use of dogs. Raking can http://joanrigdon.com/clips/truffle.ht seriously disrupt soil structure and break ml. up mycorrhizae and fine roots. Economically speaking,raking unearths Rawlinson PF, Evans F, Trappe JM. 1995. The North American Truffling appointed him Adjunct Professor of Society: Introduction to its series on Forest Science. Retiring in 1986, he truffles and truffle-like fungI. joined the Department of Forest Science Mycotaxon 60: 171-174. full time; in 1996 he again retired to pursue his favorite interest, truffles. Trappe JM, Jumpponen AM, Cazares E. Since 1996 he has spent several months 1996. NATS truffle and truffle-like a year in Australia, consulting with and fungi 5: Tuber lyonii (= T. texense), doing research on truffles and other with a key to the spiny-spored Tuber fungi for the Commonwealth Scientific species groups. Mycotaxon 60: 365- and Research Organization Division of 372. Sustainable Ecosystems at Canberra. Jim has published more than 400 scientific Trappe JM, Molina R, Luoma DL, papers and has co-authored 3 books on Cázares C, Pilz D, Smith JE, mycorrhizal fungi. Alone and with Castellano MA, Miller ML, Trappe collaborators he has formally described M. 2009. Diversity, ecology and 3 new familes, 35 newgenera, and 145 conservation of truffle fungi in forests new species of fungi. of the Pacific Northwest. USDA Forest Service, Pacific Northwest Research Station Geneneral Technical Report-GTR-772, Portland, OR. 195 pp.

Trappe JM, Sundberg 1977. Terfezia gigantean (Tuberales ) in North America. Mycologia 49: 433-437.

Trappe MJ, Evans F, Trappe JM. 2007. A Field Guide to North American Truffles. Ten Speed Press, Berkeley. 136 pp.

Trappe MJ, Trappe JM, Bonito G. 2010. Kalapuya brunnea gen. & sp. nov. and its relationship to other sequestrate genera in the Morchellaceae. Mycologia (in press).

Biosketch

Jim Trappe entered the world of wild edible fungi while doing his Ph.D. thesis on mycorrhizae at the University of Washington. He became captivated with truffles when he found them common in Douglas-fir forests of the Pacific Northwest and has focused on their ecology and for the last 45+ years. He joined the Pacific Northwest Research Station in 1962 as a Research Scientist, becoming Principal Mycologist at its Forestry Sciences Laborator on the campus of Oregon State University at Corvallis, which