Major Groups > True Morels and Verpas

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The Morchellaceae: True Morels and Verpas  

[ Ascomycetes > Pezizales . . . ]

by Michael Kuo

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 content. 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).

As all mushroom hunters know, the morels are among the best edible mushrooms on earth--but I recommend avoiding the rest of the Morchellaceae family. One of the verpas, Verpa bohemica, is known to be mildly poisonous to some people--and Disciotis venosa, while edible, is very difficult to separate from a host of other springtime cup fungi, some of which may be poisonous.

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


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


1.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).
2

1.Cap more or less fully attached to the stem--or attached about halfway down.
3


2.Cap smooth or with vague, irregular wrinkles; mushroom small to medium in size (3-11 cm tall) when mature.
Verpa conica
(Morphological species.)

2.Cap deeply and prominently wrinkled; mushroom sometimes larger than above when mature.
Verpa bohemica
(Morphological species.)


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

3.Not as above.
4


4.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.

4.Not as above.
5


5.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.)

5.Not as above.
6


6.Ridges darkening to dark brown or nearly black with maturity.
7

6.Ridges not darkening with maturity.
9


7.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.)

7.Not as above.
8


8.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.

8.Not as above.
Black Morels
(4 N. Am. taxa.)


9.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.)

9.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 (To be developed.)
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


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Cite this page as:

Kuo, M. (2005, January). The Morchellaceae: True morels and verpas. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/morchellaceae.html