Morchella ulmaria

Description

Morchella ulmaria, commonly known as the "Elm Morel," is a fungus species belonging to the Morchellaceae family. It was officially described as a new species in the scientific realm in the year 2012 by Philippe Clowez. During the same year, Michael Kuo and colleagues also introduced the species Morchella cryptica, which was subsequently identified as a junior synonym of M. ulmaria, essentially indicating that these two names refer to the same species.

This fungus is found in forested regions of Midwestern North America. It tends to be associated with specific tree species such as the white ash (Fraxinus americana), the American tulip tree (Liriodendron tulipifera), various types of maple trees, and elms. Its habitat preference suggests a symbiotic relationship with these trees.

Morchella ulmaria is closely related to M. castanea and two unnamed Asian species. These associations indicate its place within the complex network of Morchella species.

It's important to note that the geographical range of M. ulmaria overlaps with that of another species, M. americana. These two species are difficult to distinguish based solely on their physical characteristics, making DNA sampling a crucial tool for their accurate identification.

Physical caracteristics and data

Ascomia

6-20 cm tall, formed by a distinct apothecia and stipe

apothecium

4-7.5 cm in height, 3.2-6.2 cm in diameter. at the widest point. often ovoid and convex, conical-truncated or conical at the apex, adnate at the point of attachment to the foot

Hymenophore

dimpled and ribbed; with 10-18 vertical ribs crossing a line across the widest portion, but also with many horizontal and oblique ribs, in addition to transverse ribs scattered and depressed, with ribs flattened at first, then acute or eroded with age, glabrous or nearly so, pale yellowish at first, often remaining so at maturity, sometimes slightly darkening to brownish yellow, with cells often vertically elongated, but not so distinctly, and sometimes subglobose to irregular in outline, glabrous, greyish-yellow to gray or greyish-brown pale when young, then pale yellowish or pale brownish-yellow (often concolorous to ribs when mature)

Internal surface

pubescent, whitish

Foot

5-13 cm in height; 1.4-6 cm in diam., often subclaved to clavate at base when ripe, but sometimes ± equal throughout development, sometimes developing large superficial ribs, finely mealy with whitish or almost glabrous granules, on a whitish ground

Context

about 1-2 mm thick in hollow hymenophore, often becoming thickened and chambered near base of stipe, whitish

Asci

cylindrical, distinctly forked at base. 8-spored, hyaline, 175-300 x 15-25 µm

Paraphyses

cylindrical, often rounded, subclavate, sometimes clavate to broadly subfusiform at apex, septate, hyaline to brownish in KOH (2%, 100-160 x 5-12.5(15) µm

Acroparaphyses

scattered (sometimes difficult to locate or distinguish from paraphyses), subcapitate, capitate, subclavate, clavate, or broadly subfusiform, terminal cell broadly cylindrical and rounded at apex, septate, hyaline in 2% KOH, 75-125(175) x 10-30 µm

Spores

ellipsoidal, smooth, homogeneous content, 18-23 x 10-13(15) µm

Ecology

in deciduous forests, especially in apparent association with F. americana, but also reported under L. tulipifera and Acer spp.; fairly common in the Great Lakes region, from Ontario to central Illinois and western Pennsylvania

Period

April, May and June

Morchella ulmaria (Elm Morel) Edibility

Edible of choice. Poisonous when eaten raw or undercooked. Morchella species) are a popular and sought-after edible mushroom, they should never be eaten raw. Consuming raw morels or undercooked morels can lead to gastrointestinal discomfort, as they contain a mild toxin known as hydrazine. Proper cooking is essential to make them safe for consumption.

To prepare morel mushrooms for consumption:
Clean the morels: Gently clean the morel mushrooms by brushing off any dirt or debris. You can also soak them briefly in saltwater to help remove any potential insects or contaminants, but be sure to rinse them thoroughly afterward.
Slice or halve: Slice the morels lengthwise or halve them, depending on your preference.
Cook thoroughly: Morel mushrooms should be cooked thoroughly by sautéing, frying, or simmering. Cooking breaks down the hydrazine toxin and makes the mushrooms safe to eat. It's recommended to cook them for at least 15-20 minutes to ensure complete cooking.
Use in recipes: Morels are often used in various culinary dishes, such as sautés, omelets, sauces, and more. They have a unique and earthy flavor that pairs well with many dishes.

Hydrazine effect

Hydrazine is a chemical compound found in certain species of morel mushrooms. When ingested in small amounts, it can cause gastrointestinal discomfort and symptoms such as nausea, vomiting, and diarrhea. These symptoms can be relatively mild but can be quite uncomfortable.
In more severe cases, hydrazine toxicity may lead to more significant health issues, including liver and kidney damage. However, it's important to note that severe toxicity from morel mushrooms is rare, and most cases involve mild gastrointestinal distress.
The key to avoiding hydrazine-related issues is to cook morel mushrooms thoroughly. Proper cooking breaks down the hydrazine and renders the mushrooms safe to eat. So, as long as you cook morel mushrooms properly, you should be able to enjoy their unique flavor without experiencing significant adverse effects.

Remarks

M. ulmaria (= cryptica) corresponds to the phylogenetic species Mes-11 in O'Donnell and cool. (2011). Based on available data, this species cannot be reliably separated from M. americana (= esculentoides) by morphological characters, although the hymenophore of M. ulmaria (= cryptica) is frequently slightly paler and its ribs are often more flattened. The studied microscopic characters of the two species are virtually identical, except that the asci are distinctly forked at the base in M. ulmaria (= cryptica). The latter is not so often found as M. americana (= esculentoides). However, these two species were collected under hardwoods, often in apparent association with Fraxinus spp. Future collections of Mr. americana should result in more reliable separation traits between these two phylogenetic species. She was undoubtedly referred to as ''Mr. esculenta'' in presentations in North America from the Great Lakes region (eg Weber 1995). It corresponds to the ''Classic North American yellow morel II'' of Kuo (2005).

References

1.Kuo, M. & Coll. (2012). Taxonomic revision of true morels (Morchella) in Canada and the United States. Mycology.