The Morchellaceae: True Morels and Verpas (MushroomExpert.Com)

Major Groups > True Morels and Verpas

MushroomExpert.Com

The Morchellaceae: True Morels and Verpas

[ Ascomycetes > Pezizales . . . ]

The Morchellaceae family includes the true morels (members of the genus Morchella), the verpas (in the genus Verpa), and the cup fungi in the genus Disciotis. Under the microscope, these mushrooms all have asci that do not turn blue in iodine, and spores that are smooth, elliptical, and have homogeneous contents. The principal defining feature of the family, however, is the number of nuclei found in Morchellaceae spores. So far the family has held up under the scrutiny of DNA analysis; a 1997 study by O'Donnell and others upheld the traditional idea that Morchella, Verpa, and Disciotis belong together (the study wreaked havoc on the Helvellaceae, however).

The material below represents my understanding of the morels and verpas of North America, based on study of morels in the Morel Data Collection Project and collections of North American verpas (Disciotis venosa is treated with the cup fungi). DNA studies have not yet focused on the genus Verpa, to my knowledge, so for the time being we are left with two North American species that are easily separated on the basis of their physical features. The morels, however, are no longer easy to figure out.

On the present data, it appears that only four of the 16 DNA-defined morels in the MDCP can be easily separated on the basis of physical features (in combination with consideration of distribution and ecological factors), while four "species groups" can also be determined. Fortunately, the two or three morels that are difficult to identify to one of the species groups are among the four morels that are easily identified individually. It should be noted that I am using the term "species group" rather uncritically, since the groups merely consist of morels that cannot be separated by examination of physical features; the mushrooms in the groups are not necessarily related in any scientific sense, despite their apparent similarities. See Identifying Morels with Morphology for further information on identifying morels by observing their physical features.

Verpa bohemica

Morchella sp.

Morchella sp

Disciotis venosa

Key to Verpas and DNA-Defined True Morels in North America

Cap attached to the stem only at the very top, hanging like a thimble on the end of a pencil (slice the mushroom in half to view it in cross-section).

Cap more or less fully attached to the stem--or attached about halfway down.

Cap smooth or with vague, irregular wrinkles; mushroom small to medium in size (3-11 cm tall) when mature; asci 8-spored; spores 21-26 µ long.

Verpa conica
(Morphological species.)

Cap deeply and prominently wrinkled; mushroom sometimes larger than above when mature; asci 2-spored; spores 54-80 µ long.

Verpa bohemica
(Morphological species.)

Young cap usually pointed; young pits dark, contrasting with pale ridges; young surfaces bruising reddish orange to salmon; mature pits and ridges dull yellow; growing in landscaping settings along the Pacific Coast or in disturbed ground on the Gulf Coast of Mexico.

Morchella rufobrunnea

Not as above.

Young cap and stem surface densely fuzzy; stem and cap usually dark gray to blackish but occasionally pale yellow or brown, especially when exposed to prolonged sunlight; usually growing in conifer burn sites; apparently limited to the western mountains; stem surface with bundles of cystidia-like elements with dark brown walls in a 2% KOH mount.

Morchella tomentosa

Not as above.

Mature cap with pale yellowish brown ridges and pits; ridges and pits more or less vertically arranged; cap attaching to the stem with a shallow "rim" (big enough to serve as an ant race track); cap shape fairly conical in most collections; growing in non-burned forests in western North America. (This mushroom has the stature of a black morel and the colors of a yellow morel.)

Western Blond

Not as above.

Ridges darkening to dark brown or nearly black with maturity.

Ridges not darkening with maturity.

Cap attached to the stem roughly half-way up, with a substantial portion hanging "free"; mature stem often long in proportion to cap; stem often fragile.

Half-Free Morels
(2 N. Am. taxa.)

Not as above.

Growing in landscaping areas in the Pacific Northwest; mature cap often featuring prominent and regular vertical ridges with sunken cross-ridges (appearing "laddered"); young stem surface with a fine, dark gray dusting that is often retained near the stem base in maturity.

Taxon J

Not as above.

Black Morels
(4 N. Am. taxa.)

Mushroom small to medium in size; cap often pointed; pits and ridges sparse, vertically arranged; mature stem often fairly long in proportion to the cap.

Deliciosa Morels
(2 N. Am. taxa.)

Mushroom small to large in size; cap usually rounded; pits and ridges dense, randomly arranged; mature stem usually about as long as the cap is tall (but sometimes becoming very large and inflated).

Yellow Morels
(4 N. Am. taxa.)

Excluded Species and Doubtful Names

The species below represent invalid names or names that cannot currently be applied to North American morels with scientific accuracy; follow the links for detailed explanations.

Morchella angusticeps Peck
Morchella atrotomentosa (Moser) Bride
Morchella conica Krombh. (To be developed.)
Morchella crassipes (Vent.) Pers. (To be developed.)
Morchella deliciosa Fr. (To be developed.)
Morchella esculenta (L) Pers.
Morchella elata Fr. (To be developed.)
Morchella semilibera DC. (To be developed.)
Morchella vulgaris (Pers.) Boud. (To be developed.)

References

Amir, R. et al. (1992). Formation of sclerotia by Morchella esculenta: relationship between media composition and turgor potential in the mycelium. Mycological Research 96: 943-948.

Amir, R., Levanon, D. et al. (1993). Morphology and physiology of Morchella esculenta during sclerotial formation. Mycological Research 97: 683-689.

Amir, R. et al. (1994). The role of source-sink relationships in translocation during sclerotial formation by Morchella esculenta. Mycological Research 98: 1409-1414.

Amir, R. et al. (1995). Factors affecting translocation and sclerotial formation in Morchella esculenta. Experimental Mycology 19: 61-70.

Amir, R. et al. (1995). Turgor changes in Morchella esculenta during translocation and sclerotial formation. Experimental Mycology 19: 129-136.

Apfelbaum, S. I. Et al. (1984). Ascocarp formation by Morchella angusticeps after wildfire. The Michigan botanist 23: 99-102.

Brock, T. D. (1951). Studies on the nutrition of Morchella esculenta Fries. Mycologia 43: 402-422.

Bunyard, B. A. et al. (1994). A systematic assessment of Morchella using RFLP analysis of the 28s ribosomal RNA gene. Mycologia 86: 762-772.

Bunyard, B. A. et al. (1995). Phylogenetic resolution of Morchella, Verpa, and Disciotis [Pezizales: Morchellaceae] based on restriction enzyme analysis of the 28S ribosomal RNA gene. Experimental Mycology 19: 223-233.

Buscot, F. & Roux, J. (1987). Association between living roots and ascocarps of Morchella rotunda. Transactions of the British Mycological Society 89: 249-252.

Buscot, F. (1989). Field observation on growth and development of Morchella rotunda and Mitrophora semilibera in relation to forest soil temperature. Canadian Journal of Botany 67: 589-593.

Buscot, F. & Kottke, I. (1990). The association of Morchella rotunda (Pers.) Boudier with roots of Picea abies (L.) Karst. New Phytologist 116: 425-430.

Buscot, F. & Bernillon, J. (1991). Mycosporins and related compounds in field and cultured mycelial structures of Morchella esculenta. Mycological Research 95: 752-754.

Buscot, F. (1992). Mycorrhizal succession and morel biology. In Mycorrhizas in Ecosystems. Ed. D. H. Lewis et al. C.A.B. International. 220-224.

Buscot, F. (1992). Synthesis of two types of association between Morchella esculenta and Picea abies under controlled culture conditions. Journal of Plant Physiology 141: 12-17.

Buscot, F. (1993). Mycelial differentiation of Morchella esculenta in pure culture. Mycological Research 97: 136-140.

Buscot, F. et al. (1996). DNA polymorphism in morels: PCR/RFLP analysis of the ribosomal DNA spacers and microsatellite-primed PCR. Mycological Research 100: 63-71.

Candolle, A. P. de & J. B. A. P. M. de Lamarck (1815). XXIX Morille Morchella semilibera. Flore Francaise. Ed. 3, vol. 2. Paris: 212-213.

Chen, J.-Y. & P.-G. Liu (2005). A new species of Morchella (Pezizales, Ascomycota) from southwestern China. Mycotaxon 93: 89-93.

Dahlstrom, J. L. et al. (2000). Mycorrhiza-like interaction by Morchella with species of the Pinaceae in pure culture synthesis. Mycorrhiza 9: 279-285.

Dalgleish, H. J. & K. M. Jacobson (2005). A first assessment of genetic variation among Morchella esculenta (morel) populations. Journal of Heredity 96: 396-403.

Duchesne, L. C. & Weber, M. G. (1993). High incidence of the edible morel Morchella conica in a jack pine, Pinus banksiana, forest following prescribed burning. The Canadian Field-Naturalist 107: 114-116.

Fine, G. A. (1998). Morel tales: The culture of mushrooming. Cambridge: Harvard UP. 324 pp.

Fries, E. M. (1822). Morchella, Helvella. Systema Mycologicum, Vol. II (Reprint: Confederatio Europaea Mycologiae Mediterraneensis A. E., 1994): 5-18.

Gessner, R. V. et al. (1987). Allelic variation and segregation in Morchella deliciosa and M. esculenta. Mycologia 79: 683-687.

Gessner, R. V. (1995). Genetics and systematics of North American populations of Morchella. Canadian Journal of Botany 73 (Suppl. 1): S967-S971.

Goldway, M. et al. (2000). Morchella conica exhibiting a long fruiting season. Mycological Research 104: 1000-1004.

Grove, J. W. & Hoare, S. C. (1953). The Helvellaceae of the Ottawa district. The Canadian Field-Naturalist 67: 96-102.

Guzmán, G. & Tapia, F. (1998). The known morels in Mexico, a description of a new blushing species, Morchella rufobrunnea, and new data on M. guatemalensis. Mycologia 90: 705-714.

Harbin, M., & Volk, T. J. (1999). The relationship of Morchella with plant roots. Abstract #1601: XVI International Botanical Congress, St. Louis, Missouri, USA. p. 59.

Hervey, A. et al. (1978). Cultural studies of single ascospore isolates of Morchella esculenta. Mycologia 70: 1269-1274.

Jacquetant, E. (1984). Les morilles. Paris: La Biblioteque des Arts. 114 pp.

Jung, S. W. et al. (1993). Systematics of Morchella esculenta complex using enzyme-linked immunosorbent assay. Mycologia 85: 677-684.

Kellner, H., Renker, C. & Buscot, F. (2005). Species diversity within the Morchella esculenta group (Ascomycota: Morchellaceae) in Germany and France. Organisms, Diversity & Evolution 5: 101-107. This paper is available online here.

Kellner, H., P. Luis & F. Buscot (2007). Diversity of laccase-like multicopper oxidase genes in Morchellaceae: identification of genes potentially involved in extracellular activities related to plant litter decay. Microbiological Ecology 61: 153-163.

Krombholz, J. V. (1834). Naturgereue Abbildungen und Beschreibungen der essbaren, schadlichen und verdachtigen Schwamme. Prague: J. G. Calve. [Morchella (III: 1-16)].

Kuo, M. (2005). Morels. Ann Arbor: University of Michigan Press. 205 pp.

Kuo, M. (2008). Morchella tomentosa, a new species from western North America, and notes on M. rufobrunnea. Mycotaxon 105: 441-446.

Li, S. H., Y. C. Zhao, H. M. Chai & M. H. Zhong (2006). Two new species in the genus Morchella (Pezizales, Morchellaceae) from China. Mycotaxon 95: 319-322.

Linne, C. (Linnaeus). (1753). Phallus. In: Species plantarum: exhibentes plantas rite cognitas ad genera relatas. Tomus II . Page 1178. Linnaeus's Species Plantarum is online here; use the left-hand navigation box to select "Phallus" on page 1178.

Linne, C. (Linnaeus). (1767). Phallus. In: Systema Naturae per Regna Tria Naturae, secundum Classes, Ordines, Genera, Species, cum Charicteribus & Differentiis. Tomus II. Page 724. Linnaeus's Systema is online here; use the left-hand navigation box to select "Phallus" on page 724.

Masaphy, S. (2005). External ultrastructure of fruit body initiation in Morchella. Mycological Research 109: 504-512.

McFarlane, E. M., Pilz, D. & Weber, N. S. (2005). High-elevation gray morels and other Morchella species harvested as non-timber forest products in Idaho and Montana. Mycologist 19: 62-68.

Mihail, J. D. et al. (2007). Spatial and temporal patterns of morel fruiting. Mycological Research 111: 339-346.

Miller, S. L. et al. (1994). Persistence of basidiospores and sclerotia of ectomycorrhizal fungi and Morchella in soil. Mycologia 86: 89-95.

Moser, M. (1949). Uber das massenauftreten von Formen der Gattung Morchella auf Waldbrandflachen. Sydowia, Annales Mycologici ser. II, 3: 174-195.

O'Donnell, K. O., et al. (1997). Phylogenetic relationships among ascomycetous truffles and the true and false morels inferred from 18S and 28S ribosomal DNA sequence analysis. Mycologia 89: 48-65.

Ower, R. (1982). Notes on the development of the morel ascocarp: Morchella esculenta. Mycologia 74: 142-144.

Ower, R. D. et al. (1985). United States Patent 4,594,809: Cultivation of Morchella. Retrieved April 7, 2006 from the United States Patent Office Web site. (Available online here.)

Peck, C. H. (1887). Morchella angusticeps. Bulletin of the New York State Museum 2: 19.)

Persoon, C. H. (1801). Helvella, Morchella. Synopsis Methodica Fungorum. Gottingen. 614-621. The Synopsis is online here; navigate to page 614 to begin this excerpt.

Pilz, D. et al. (2004). Productivity and diversity of morel mushrooms in healthy, burned, and insect-damaged forests of northeastern Oregon. Forest Ecology and Management 198: 367-386.

Pilz, D. et al. (2007). Ecology and management of morels harvested from the forests of western North America. Portland, Oregon: USDA General Technical Report. 161 pp. This publication is available online at the Forest Service: http://www.fs.fed.us/pnw/publications/gtr710/

Robbins, W. J. & Hervey, A. (1959). Wood extract and growth of Morchella. Mycologia 51: 356-363.

Royse, D. J. & May, B. (1990). Interspecific allozyme variation among Morchella spp. and its inferences for systematics within the genus. Biochemical Systematics and Ecology 18: 475-479.

Schmidt, E. L. (1979) Puffing in Morchella. Bulletin of the British Mycological Society 13: 126-127.

Schmidt, E. L. (1983). Spore germination of and carbohydrate utilization by Morchella esculenta at different soil temperature. Mycologia 75: 870-875.

Singh, S. K. et al. (2004). Arbitrary primer based RAPD�A useful genetic marker for species identification in morels. Journal of Plant Biochemistry & Biotechnology 13: 7-12.

Singh, S. K., M. Tiwari, S. Kamal & M. C. Yadav (2005). Morel phylogeny and diagnostics based on restriction fragment length polymorphism analysis of ITS region of 5.8S ribosomal RNA gene. Journal of Plant Biochemistry and Biotechnology 14: 179-183.

Tiffany, L. H. et al. (1998). Distribution and ecology of the morels and false morels of Iowa. Journal of the Iowa Academy of Science 105: 1-15.

Volk, T. J. & Leonard, T. J. (1989). Experimental studies on the morel. I. Heterokaryon formation between monoascosporous strains of Morchella. Mycologia 81: 523-531.

Volk, T. J. & Leonard, T. J. (1990). Cytology of the life-cycle of Morchella. Mycological Research 94: 399-406.

Weber, N. S. (1995). A morel hunter's companion: A guide to true and false morels. Michigan: Thunder Bay Press. 209 pp.

Winder, R. S. (2006). Cultural studies of Morchella elata. Mycological Research 110: 612-623.

Wipf, D. et al. (1996). DNA polymorphism in morels: Complete sequences of the internal transcribed spacer of genes coding for rRNA in Morchella esculenta (yellow morel) and Morchella conica (black morel). Applied and Environmental Microbiology 62: 3541-3543.

Wipf, D., S. Koschinsky, P. Clowez, J. C. Munch, B. Botton & F. Buscot (1997). Recent advances in ecology and systematics of morels. Cryptogamie, Mycologie 18: 95-109.

Wipf, D. et al. (1999). Diversity of the internal transcribed spacer of rDNA in morels. Canadian Journal of Microbiology 45: 769-778.

Wurz, T. L. et al. (2005). Harvesting morels after wildfire in Alaska. USDA: Research Note PNW-RN-546.

Yoon, C. et al. (1990). Population genetics and systematics of the Morchella esculenta complex. Mycologia 82: 227-235.

Cite this page as:

Kuo, M. (2008, November). The Morchellaceae: True morels and verpas. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/morchellaceae.html