Morchella esculenta

Morchella esculenta

The common morel, morel, yellow morel, true morel, morel mushroom or sponge morel (Morchella esculenta (L.) Pers., 1794) is a fungus belonging to the Morchellaceae family.

Systematics –
Domain Eukaryota,
Kingdom Fungi,
Division Ascomycota,
Subdivision Pezizomycotina,
Class Pezizomycetes,
Subclass Pezizomycetidae,
Order Pezizales,
Family Morchellaceae,
Genus Morchella,
Species esculenta.
The following terms are a basionym:
– Phallus esculentus L.
Synonyms include:
– Coelomorum esculentum (L.) (1808);
– Helvella esculenta (L.) (1796);
– Morchella abietina Leuba, Champ. (1890);
– Morchella americana var. rigida (Krombh.) Clowez & P.-A. Moreau (2020);
– Morchella conica Pers., (1818);
– Morchella continua Tratt. (1830);
– Morchella cylindrica Velen. (1925);
– Morchella distans Fr. (1849);
– Morchella dunensis Castañera, J.L. Alonso & G. Moreno (1997);
– Morchella esculenta fulva Fries (1822);
– Morchella esculenta longipes Peck (1876);
– Morchella esculenta rotunda Pers. (1801);
– Morchella esculenta vulgaris Pers. (1801);
– Morchella lutescens Leuba (1890);
– Morchella ovalis f. pallida (Jacquet.) Clowez & Luc Martin (2012);
– Morchella prunarii Schulzer & Hazsl. (1882);
– Morchella pubescens Pers. (1834);
– Morchella rigida (Krombh.) (1897);
– Morchella rotunda Boud (1897);
– Morchella rotunda Pers. (1897);
– Morchella tremelloides (Vent.) Pers. (1801);
– Morchella umbrina Boud. (1897);
– Morchella viridis Leuba, Champ. comest.: pl. 46, fig. 3-5 (1890);
– Morchella vulgaris Boud. (1897);
– Morchella vulgaris var. alba Boud. (1910);
– Morellus esculentus (L.) Eaton (1818);
– Morilla conica (Pers.) Quél. (1886);
– Morilla esculenta (L.) Quél. (1886);
– Morilla tremelloides (Vent.) Quél. (1886);
– Morilla villica var. tremelloides (Vent.) Quél. (1886);
– Phalloboletus esculentus (L.) Kuntze (1891);
– Phallus esculentus L. (1753);
– Phallus tremelloides Vent. (1797).
This mushroom also comes in many varieties:
– var. rigida, with a large, ovoid or slightly conical cap, egg-yellow, short, flat-bottomed sockets, and a thick stem;
– var. rotunda, with a large, round or ovoid cap, straw-yellow, with deep, irregular sockets;
– var. vulgaris, with a medium-sized, ovoid or obtuse-conical cap, brownish-gray;
– var. crassipes, with a large, ovoid cap, yellowish-brown, with a very elongated stem, thickened at the base;
– var. umbrina, small, spherical, coal-black, with round, deep sockets, and a bulbous white stem.

Etymology –
The term Morchella derives from the German “Morchel,” meaning “morel.” This name has been Latinized and refers to the appearance of the mushroom’s cap, which resembles the spongy, honeycomb surface of a sponge.
The specific epithet esculenta derives from the Latin esculenta, meaning edible.

Geographic Distribution and Habitat –
Morchella esculenta is a fungus that grows primarily in Europe and North America, but is also found in Asia. In Europe, it is widespread in several regions, including Italy, where it can be found in various environments, such as deciduous and coniferous forests, gravelly or sandy soils, riverine areas, prairies, and areas with burned soil.
In Italy, it is found, for example, in Sicily, Sardinia, the Sibillini Mountains, and in regions such as Tuscany and Trentino-Alto Adige.
In North America, it is present but was introduced starting in 1752.
It is found in some parts of Asia, although it is less common than in Europe and North America.
The fruiting bodies are sometimes solitary, but more often in clusters, on the ground in a variety of habitats. A preference for limestone-based (alkaline) soils has been noted, but they have also been found in acidic soils.
The mushroom is usually found in early spring, in forests, orchards, yards, gardens, and sometimes in recently burned areas. In North America, it is sometimes called the “May mushroom” due to its constant fruiting during that month, but the fruiting period varies locally, from February to July. It is typically the last morel species to fruit in locations where multiple species are present. For example, in northern Canada and colder mountainous regions, morels typically do not appear until June. It has been suggested that spring fruiting may be due to their ability to grow at low temperatures, excluding competition, a conclusion later corroborated by experiments correlating spore germination to soil temperatures.
In North America, it is widely distributed, but particularly common in eastern North America and the Midwest. It can also be found in Brazil.
Its fruiting habitat is under deciduous and coniferous trees for a short period in spring, depending on weather conditions, and it is also associated with old orchards, woodlands, and disturbed soils.

Identification –
Morchella esculenta is recognized by its creamy-tan, yellow to light brown, or light brown to grayish brown cap. The edges of the ridges are usually lighter than hazelnuts and slightly oval in shape, sometimes bluntly conical with a rounded or more elongated top. The caps are hollow, attached to the stipe at the lower edge, and are typically about 2-7 centimeters wide and 2-10 cm tall. The flesh is fragile.
The stipe is pale white or pale yellow, hollow, and straight, or with a club-shaped or bulbous base. It is finely granular overall, slightly grooved, generally about 2-9 cm long and 2-5 cm thick. With age, it may develop brownish spots near the base.
The flesh is white and waxy in consistency.
The odor is slightly spermatic, and the flavor is sweetish, delicate, and pleasant.
Under the microscope, spores range in color from white to cream to slightly yellow in deposit, although a spore print may be difficult to obtain given the shape of the fruiting body.
The spores form in the asci lining the pits: the ridges are sterile. They are ellipsoidal, smooth, thin-walled, translucent (hyaline), and measure 17.5–21.9 by 8.8–11.0 μm.
The asci are octosporiform, 223–300 x 19–20 μm, cylindrical, and hyaline. The paraphyses are filamentous, cylindrical, 5.8–8.8 μm wide, and hyaline.
The stem hyphae are intertwined, hyaline, and 5.8–9.4 μm wide. The superficial hyphae are swollen, spherical to pear-shaped, 22–44 μm wide, covered by a network of intertwined hyphae 11–16.8 μm wide with curved, cylindrical hyphal tips.

Cultivation –
Due to the mushroom’s valuable fruiting bodies, several attempts have been made to cultivate the fungus in culture. In 1901, Repin reported successfully obtaining fruiting bodies in a cave where cultures had been grown in flowerpots nine years earlier, in 1892.
Mycologist Taylor Piercefield developed a method using beds of young deciduous trees inoculated with mycelium, focusing on the symbiotic relationship with Morchella esculenta. Subsequently, once the mycelium had fully developed, the beds were treated with potassium hydroxide to replicate the pH conditions found in soil after a forest fire. This method produced large, ripe fruits, but was not commercially viable on a large scale. More recently, small commercial growers have been successful in growing morels using partially shaded rows of mulched wood. The rows of mulched wood are inoculated with fungal spores in a solution of water and molasses, which is poured over the mulch piles and then left to grow undisturbed for several weeks. A diluted solution of wood ash mixed with water is then poured over the wood mulched wood, triggering the morel fruiting. Morels are known to appear after fires, and the alkaline conditions produced by wood ash mixed with water trigger fruiting body formation for most morel species.
As mentioned, fruiting bodies have been successfully grown in the laboratory. R. Ower was the first to describe the developmental stages of ascomas grown in a controlled chamber. This was followed by detailed cytological studies by Thomas Volk and Leonard (1989, 1990). To study the life cycle of the morel, they followed the fruiting development of ascomas associated with tuberous begonias (Begonia tuberhybrida), from very small primordia to fully developed fruiting bodies.
The young fruiting bodies begin developing as a dense node of hyphae when adequate moisture and nutrient availability have been achieved. The hyphal nodes are underground and cup-shaped for a time, but later emerge from the soil and develop into a stalked fruiting body. Further growth makes the hymenium convex, with the asci facing outward. Due to the uneven growth of the hymenium surface, it folds over, forming numerous ridges and depressions, giving it a spongy or honeycomb appearance.

Uses and Traditions –
Morchella esculenta is a mushroom that grows across a vast global range and is known by various common names, including “common morel,” “morel,” “yellow morel,” “true morel,” “morel mushroom,” and “sponge morel” in English, and “cagarria,” “morilla” in Spanish.
In Nepal, it is known as Guchi chyau.
The mushroom was originally named Phallus esculentus by Carl Linnaeus in his Species Plantarum (1753) and was given its current name by mycologist Christiaan Hendrik Persoon in 1801.
The scientific name Morchella esculenta has been applied to many similar yellow morels around the world. In 2014, Richard et al. used DNA analysis to narrow the name M. esculenta to a single species of yellow morel commonly found in Europe and also reported in China. Other yellow morel species, including those from North America, have received new scientific names.
It is one of the most easily recognizable and highly sought-after edible mushrooms.
Similar species include:
– Gyromitra esculenta, a dark rusty brown mushroom with brain- or coral-like ridges;
– Gyromitra esculenta, a poisonous mushroom similar to M. esculenta;
Morchella esculenta is probably the best-known morel mushroom. Unlike M. angusticeps and its relatives, the caps are light-colored throughout their development, especially the ridges, which remain lighter than the pits. M. crassipes is sometimes confused with M. esculenta. According to Smith (1975), the two species are distinct, but young forms of M. crassipes are difficult to separate from M. esculenta. The two species are similar in color, but M. crassipes is larger, often has thin ridges, and sometimes has a stipe.
Impudicus mushrooms, particularly Phallus impudicus, are also similar, but have a volva at the base of the stem and are covered with gleba, a slimy, foul-smelling spore mass.
In Jammu and Kashmir, wild mushrooms, locally known as wild Himalayan mushrooms, Gucchi, Morchella conica, and M. esculenta, are collected and used as medicinal remedies.
Morchella esculenta, like all morels, is among the most prized edible mushrooms. Raw morels contain a gastrointestinal irritant, hydrazine (although it has not been isolated in samples), but blanching before consumption removes it. Old fruit bodies showing signs of decay can be poisonous.
Both the fruit bodies and mycelia of M. esculenta contain a rare amino acid, cis-3-amino-L-proline; this amino acid does not appear to be bound to proteins. Besides M. esculenta, the amino acid is known to be present only in M. conica and M. crassipes.
M. esculenta has shown promise in degrading starch and improving the nutritional value of corn flour during solid-state fermentation.
The mycelium of M. esculenta is able to bind and inhibit the effects of furanocoumarins, chemicals found in grapefruit that inhibit human cytochrome p450 enzymes and are responsible for the “grapefruit/drug” interaction phenomenon.
From an ecological perspective, millipedes sometimes nest inside these mushrooms. Infested morels usually have a hole in the top.

Preparation Instructions –
Morchella esculenta is a very tasty mushroom, but like all morels, it is toxic when raw because it contains helvellic acid, a heat-labile mycotoxin. Therefore, it should be consumed after pre-cooking, discarding the boiling water, as raw morels cause hemolytic syndrome. The toxin (hemolysin) breaks down at high temperatures, around 80°C, making the mushroom edible for humans.
These mushrooms can be fried in butter or baked after being stuffed with meat and vegetables. Mushrooms can also be dried by stringing the caps and hanging them in the sun; this process is said to concentrate the flavor.
The nutritional value and nutrients in 100 grams of raw Morella esculenta: 12 kcal, 89 g water, 1.7 g protein, 0.5 g usable carbohydrates, 0.3 g fat, 7 g non-usable substances, 2 mg cholesterol, 390 mg potassium, 11 mg calcium, 162 mg phosphorus, 1.2 mg iron, 16 mg magnesium, and 5 mg vitamin C.

Guido Bissanti

Sources
– Wikipedia, the free encyclopedia.
– GBIF, the Global Biodiversity Information Facility.
– Cetto B., 2008. Mushrooms from the truth, Saturnia, Trento.
– Pignatti S., 1982. Flora of Italy, Edagricole, Bologna.
– Conti F., Abbate G., Alessandrini A., Blasi C. (eds.), 2005. An annotated checklist of the Italian vascular flora, Palombi Editore.

Photo source:
– https://upload.wikimedia.org/wikipedia/commons/6/6f/Morchella_esculenta_duo.jpg

Warning: The pharmaceutical applications and dietary uses are provided for informational purposes only and do not in any way constitute medical prescriptions. We therefore decline any responsibility for their use for curative, aesthetic, or nutritional purposes.