MDCP Morel Taxa

by Michael Kuo

The morels described below are based on unpublished DNA testing of morels sent in to the Morel Data Collection Project. I have not used scientific names (with one exception), since most of the scientific names currently in use represent European species, and DNA comparisons would have to be made before these European names could be applied to North American mushrooms. The names used below are either random "taxon" numbers assigned by Dr. Carol Carter or Dr. Kerry O'Donnell, common names I have featured in my book Morels (University of Michigan Press, 2005), or common names featured in other publications.

This species was described from Mexico by Gastón Guzmán and Fidel Tapia in 1998. DNA testing of several MDCP collections from landscaping sites in California has revealed them to be the same species. Since the mushroom is very distinct, it is fairly clear that Morchella rufobrunnea is the correct name for the species described by many western authors as "Morchella deliciosa" (see this page for an example).

The trademark physical features of Morchella rufobrunnea are its frequently pointed cap (especially when young), the striking contrast of the vertically arranged ridges and pits in young mushrooms, and the fact that it is "rufescent," meaning that it blushes pinkish to salmon orange when bruised (like Amanita rubescens), especially when young.

The original, type collection (upper-left photo) was made in disturbed ground on a road embankment near the Gulf Coast of Mexico; California specimens have come from landscaping areas--usually in the winter following the landscaping activity. No woodland collections have been sent in to the MDCP--but, of course, many more collections will need to be studied before the habitat of Morchella rufobrunnea can be stated with certainty. To see MDCP collections identified as Morchella rufobrunnea, click here. See also the species page for Morchella rufobrunnea.

The Fuzzy Foot Morel

(Carter RFLP Taxon 08; O'Donnell Sequencing Taxon I)

This genetically distinct morel is easily distinguished by its fuzzy stem and its densely velvety young cap. So far, it has been collected in western burn areas, but it would be premature to assume it only appears in burns. The Fuzzy Foot Morel is often called the "gray morel" by western collectors, and the scientific name Morchella atrotomentosa has been erroneously applied to the mushroom as well. The latter name was coined in 1949 by Moser, a European mycologist who was describing an Alpine morel. However, Moser's "Morchella esculenta var. atrotomentosa" was never validly published as a species name, and DNA comparison to European morels has not been published, so the name cannot be accurately applied to the Fuzzy Foot Morel.

The map below represents MDCP collections, to date, of the Fuzzy Foot Morel--but reports of morels matching the description of the Fuzzy Foot have been made from most states and provinces west of the Rocky Mountains. The right-hand illustration shows the elongated, pigmented (in 2% KOH) cells on the surface of the Fuzzy Foot Morel's stem; other MDCP morels I have examined lack the pigmentation.

After I labeled this mushroom the "Black Foot Morel" in my book Morels (2005), several pale-stemmed, pale-capped MDCP collections have been identified as genetic matches (see the photos below for an example). The collections appear to represent mature specimens, and analysis of collection dates and collectors' notes indicates the possibility that the Fuzzy Foot may fade rapidly in prolonged sunlight, appearing more like a yellow morel than a black morel in maturity. The surfaces, however, retain their fuzziness--and, under the microscope, the cells on the stem surface retain their distinctive pigmentation. There is some evidence that the Fuzzy Foot's DNA, like the DNA of the Western Blond, bridges the yellow and black morel groups.

To see MDCP collections identified as the Fuzzy Foot Morel, click here.

The colors of the Western Blond suggest a yellow morel, since the ridges do not darken with age and the overall color of the cap is fairly pale throughout development--though the mature cap colors are just a little bit browner than the colors of the "typical" yellow morel (for example, the Classic Yellow Morel). The stature of the Western Blond, however, suggests a black morel; the pits and ridges are more vertically arranged than those of the esculenta-like yellow morels, and the cap attaches to the stem with a shallow "rim"--a feature not usually found with yellow morels.

The photo to the left represents a collection of "natural blonds" I have seen from northern California (Sonoma County, February 2003), and the mushrooms appear to match the Western Blond. If you would like to kick me for A) not saving specimens for scientific study, and B) taking such a lousy photo, I will understand. In my defense I will say only that the Morel Data Collection Project had not yet been conceived. I remember being confused by the morels, as a midwestern collector, and wondering whether they were "yellow" or "black" morels, since they seemed to display features from both groups.

This yellow morel is found across North America. It grows in a wide variety of ecosystems; it is often found under ash and dying elms, but is by no means exclusive to those trees (it is even found under conifers, in burn sites, and in landscaping settings). From a non-scientific perspective, it corresponds to the species "Morchella esculenta" featured in field guides. There is no prominent "rim" at the point where the cap attaches to the stem. The pits and ridges are not usually vertically arranged, and the top of the cap is usually not pointy. The ridges do not darken with age. When young, the pits may be dark (or nearly black), contrasting starkly with the pale ridges; mushrooms in this stage are sometimes called "grays" by midwestern and eastern collectors. In age, the pits usually fade until they are roughly the same yellowish color as the ridges.

From a scientific perspective, however, the Classic North American Yellow Morel cannot be called Morchella esculenta with certainty, since genetic comparison to the original European species by that name has not been performed and published--and because there may be several European morels "passing" as Morchella esculenta, making it impossible to determine which European mushroom represents the original species. To complicate things further, there are several North American yellow morels that (for the moment, anyway) cannot be distinguished from the Classic without examining DNA; see Taxon 12, Taxon 13, and Taxon 15.

The map to the left represents the range of the Classic Yellow as determined by DNA testing of MDCP specimens; the true range is undoubtedly wider. To see MDCP collections identified as the Classic North American Yellow Morel, click here.

This morel has been collected, so far, in the Great Lakes area and the Midwest. No physical or ecological features have emerged that would separate it from the Classic North American Yellow Morel, but relatively few collections have been made. Further collections and study may reveal distinguishing features or ecological separators.

Taxon 12 has been found under ash, sycamore, maples, tulip trees, and white pine mixed with maple. The map to the left represents the range of Taxon 12 as determined by DNA testing of MDCP specimens to date, but the true range cannot be stated with confidence until many more collections are studied. To see MDCP collections identified as Taxon 12, click here.

Another yellow morel, apparently indistinguishable from the Classic North American Yellow Morel and Taxon 12, this mushroom has been collected in sandy soils near Lake Michigan, along the Missouri River in South Dakota, near Toronto, and in a four-year-old burn area in the Montana Rockies. Further collections and study are obviously required before conclusions can be drawn. To see MDCP collections identified as Taxon 13, click here.

This mushroom represents a point of divergence in DNA testing results; RFLP indicates the possibility of a separate taxon, while sequencing apparently sees the mushroom as genetically identical to the Classic Yellow. Neither physical features nor ecological factors have emerged to separate the mushrooms without reference to RFLP results. The mushroom has been collected in Kansas, Texas, and Missouri.

The North American Deliciosa is a yellow morel with sparse, vertically arranged pits and ridges, found primarily under hardwoods (often under ash or tulip trees) east of the Great Plains. It is usually smaller than the typical Classic North American Yellow Morel, and frequently has a pointy cap. "Gray" forms are common, representing immature forms or ecotypes in which the pits are dark. The ridges are pale throughout development. There is no substantial "rim" at the point where the cap attaches to the stem.

Taxon 2 is one of two genetically distinct North American morels matching Elias Fries's 19th-century description of Morchella deliciosa in Sweden (the apparently indistinguishable Taxon 3 is the other one). Whether or not one or the other of these mushrooms is genetically identical to Fries's mushroom is still to be determined. In the meantime, I am calling them both "North American Deliciosas," using the name as a "common name" rather than a scientific name. Morchella deliciosa as described by Weber (1995) corresponds to the North American Deliciosas in the MDCP, but the "Morchella deliciosa" described by many western authors (e.g. Arora, 1986) is probably Morchella rufobrunnea. To complicate things further, some authors (including Lincoff, 1992; Bessette, Bessette & Fischer, 1997; and Roody, 2003) describe a large, white morel with dark pits as "Morchella delciosa" in an erroneous interpretation of Fries's original description. The mushrooms described by these authors are probably merely immature forms or ecotypes of the Classic North American Yellow Morel.

The red areas in the map to the left represent DNA-verified collections of Taxon 2. Gray areas represent the range of reported Morchella deliciosa-like morels. Blue areas represent the DNA-verified range of Taxon 3. To see MDCP collections identified as Taxon 2, click here.

Only a few MDCP collections represent Taxon 3, and it is apparently indistinguishable (for the time being, anyway) from Taxon 2 without reference to its DNA. Taxon 3 has been found under hickories and Tulip Trees in Mississippi, Ohio, South Carolina, and Virginia--but there is not enough data to state its range or tree associations with confidence. Taxon 3 meets the physical description of the European species Morchella deliciosa; for details, see the comments and description for Taxon 2.

The blue dots on the map below represent DNA-verified collections of Taxon 3. Gray areas represent the range of reported Morchella deliciosa-like morels. Red areas represent the DNA-verified range of Taxon 2. To see MDCP collections identified as Taxon 3, click here.

Our Classic Black Morel appears to be transcontinental. It is extremely variable in appearance, and quite cosmopolitan. It probably lacks a valid scientific name; the labels Morchella conica and Morchella elata, often applied to this mushroom by North American authors, both represent European species that were inadequately described and for which type collections do not exist (making it impossible to compare DNA)--and the label Morchella angusticeps, which comes from 19th-century New York mycologist Charles Peck, refers to a species with a pointy head that the author illustrated as a yellow morel with white ridges (click here to see Peck's illustration). DNA comparison with Peck's type collection has not been published.

The Classic Black Morel has ridges that become black by maturity, and pits that are yellowish or tan. The stem is white or tan, and can be smooth, grainy, wrinkled, or ribbed. There is a small "rim" at the point where the cap attaches to the stem. The Classic Black is common in hardwood forests east of the Great Plains, but it is also collected in western burn sites, conifer forests across the continent, and landscaping areas.

Several black morels may be indistinguishable from the Classic Black; see Taxon 4, Taxon 6, and Taxon 7, below. Hopefully, further study will reveal ways to separate these mushrooms without reference to their DNA. The map to the left represents the range of the Classic Black as determined by DNA testing of MDCP specimens; the true range is undoubtedly wider. To see MDCP collections identified as the Classic Black, click here.

Collections of this black morel have been made in California, the Pacific Northwest, the northern Rocky Mountains, and Texas. Its habitat is apparently variable, and includes burn sites. Despite its clear genetic difference, no physical or ecological features have emerged to separate it from the Classic Black--but further study is required.

The map to the left represents the states where this mushroom has been collected, to date, but conclusions should not be drawn about the true range of the mushroom. To see MDCP collections identified as Taxon 7, click here.

Collections of this black morel have been made in burn sites in the Pacific Northwest. No physical or ecological features have emerged to separate it definitively from the Classic Black--but only a few MDCP collections have made, and further study is required.

The map to the left represents the states where Taxon 6 has been collected, to date, but conclusions should not be drawn about the true range of the mushroom. To see MDCP collections identified as Taxon 6, click here.

This mushroom represents a point of divergence in DNA testing results; RFLP indicates the possibility of a separate taxon, while sequencing apparently sees the mushroom as genetically identical to the Classic Black. Neither physical features nor ecological factors have emerged to separate the mushrooms without reference to RFLP results. The mushroom has been collected in Oregon, Wisconsin, Michigan, and New Jersey, under various trees. To see MDCP collections identified by RFLP as Taxon 4, click here.

This mushroom represents a point of divergence in DNA testing results; sequencing indicates the possibility of a separate taxon, while RFLP apparently sees the mushroom as genetically identical to the Classic Black. Taxon J is both physically and ecologically distinct. Its cap features vertically arranged pits and ridges that develop a "laddered" appearance (with sunken, horizontal cross-ribs), and its stem is fairly dark when young. MDCP collections have come only from landscaping areas in the Pacific Northwest, suggesting that Taxon J may be an introduced organism and that, like Morchella rufobrunnea, it does not require mycorrhizal association to succeed.

Taxon 11 & Taxon 14: North American Half-Free Morels

(Carter RFLP Taxon 11 and Taxon 14; O'Donnell Sequencing Taxon A and Taxon N)

At least two half-free morels occur in North America, according to DNA tests of MDCP specimens. Taxon 14/N, shown in the bottom illustration, is known from Oregon, and has only been collected once so far. No physical or ecological features appear to separate it (based on the one collection) from the other half-free morel, Taxon 11/A (shown in the top illustration), which appears to be widely distributed east of the Great Plains. However, many more collections will need to be studied before it can be stated with confidence that distribution and range separate these genetically distinct mushrooms.

Half-Free Morels are easily separated from other morels on the basis of cap attachment; the cap is attached to the stem roughly half-way, with a bottom portion that hangs free. The half-free morels are fairly variable in appearance. When young the blunt ridges and pits are pale tan, but by maturity the ridges are typically dark and sharp-edged. The proportions of the mushrooms change dramatically as they mature; at first the stem is barely visible beneath the cap, but in maturity the stem is quite long, and often inflated.

The map to the left represents MDCP collections of half-free morels (red for Taxon 11/A, and blue for Taxon 14/N), and the range of reported half-free morels in North American field guides and other sources (gray). To see MDCP collections identified as Taxon 11/A, click here. To see MDCP collections identified as Taxon 14/N, click here.

Cite This Page As:

Kuo, M. (2006, March). North American Morels in the MDCP. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/mdcp/results_legend.html

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