What are the common names used to refer to Hydnum repandum?

Hydnum repandum is commonly known by several names, including the sweet tooth, pig's trotter, wood hedgehog, and hedgehog mushroom.

To which fungal family does Hydnum repandum belong, and what is its significance within its genus?

Hydnum repandum belongs to the family Hydnaceae and holds the distinction of being the type species of the genus Hydnum. As the type species, it serves as the primary reference for defining the characteristics of the entire genus.

How does the structure for bearing spores differ in Hydnum repandum compared to many other common mushrooms?

Unlike many mushrooms that possess gills, Hydnum repandum features spore-bearing structures in the form of spines that hang down from the underside of its cap. This unique characteristic classifies it among the group of fungi known as 'tooth fungi'.

Describe the typical appearance and color of the cap of Hydnum repandum.

The cap of Hydnum repandum is typically dry and ranges in color from yellow to light orange or brown. It often develops an irregular shape, particularly when growing in close proximity to other mushrooms, and its margin is frequently wavy.

What are the characteristics of the mushroom's tissue, including its odor, taste, and reaction to damage?

The tissue of the mushroom is white, emits a pleasant odor, and has a taste that can range from spicy to bitter. Importantly, all parts of the mushroom will stain orange when they age or are bruised.

What is the ecological role of Hydnum repandum in its environment?

Hydnum repandum functions as a mycorrhizal fungus, establishing a symbiotic relationship with trees. In this partnership, the fungus assists the tree in absorbing nutrients from the soil, while the tree provides the fungus with sugars produced through photosynthesis.

In which geographical region is Hydnum repandum broadly distributed?

Hydnum repandum is broadly distributed across Europe, where it can be found growing in various woodland settings.

Is Hydnum repandum edible, and are there any considerations regarding its taste?

Yes, Hydnum repandum is considered a choice edible species. However, it's worth noting that mature specimens can develop a bitter taste, which can often be reduced or eliminated through cooking methods like boiling.

Does Hydnum repandum have any poisonous look-alikes?

According to the provided information, Hydnum repandum does not have any poisonous look-alikes, which contributes to its relative safety for foragers.

Who first officially described Hydnum repandum, and in what year was this done?

Carl Linnaeus first officially described Hydnum repandum in his seminal work, Species Plantarum, in the year 1753.

Can you name some of the genera into which Hydnum repandum has been classified over time?

Throughout its taxonomic history, Hydnum repandum has been placed in several different genera, including Hypothele, Dentinum, Tyrodon, and Sarcodon, reflecting evolving classifications in mycology.

What is the significance of Hydnum repandum in relation to the genus Hydnum?

Hydnum repandum serves as the type species for the genus Hydnum. This designation means it is the foundational species upon which the genus's classification is based.

Which species did some mycologists believe should be the type species for the genus Hydnum instead of H. repandum?

Some mycologists, including Zdeněk Pouzar and Kenneth A. Harrison, previously suggested that Hydnum imbricatum should be designated as the type species for the genus Hydnum, rather than Hydnum repandum.

What did molecular studies reveal about the species concept of H. repandum?

Molecular studies have indicated that the traditional species concept for H. repandum may need revision. These studies have shown a poor overlap between morphological characteristics and genetic data, suggesting the existence of distinct, possibly cryptic, species within what was previously considered a single species.

What did a 2016 genetic study find regarding the diversity within the H. repandum concept?

A comprehensive genetic study conducted in 2016 revealed that the broad concept of Hydnum repandum actually encompasses at least four distinct species. These species were identified across different geographical regions, including southern China, Europe, and North America.

What does the specific epithet repandum refer to in the mushroom's name?

The specific epithet 'repandum' is derived from Latin and translates to 'bent back' or 'wavy.' This term refers to the characteristic wavy or incurved margin of the mushroom's cap.

What is the meaning behind the common French name for Hydnum repandum?

The common French name for Hydnum repandum, often used when it is sold in markets, is 'pied-de-mouton,' which translates to 'sheep's foot.' This name likely relates to the mushroom's shape or texture.

What are the typical dimensions of the cap of Hydnum repandum?

The cap of Hydnum repandum typically measures up to 17 centimeters (approximately 6.5 inches) in width, although larger specimens have been documented.

What are the usual measurements for the stipe (stem) of Hydnum repandum?

The stipe of Hydnum repandum generally measures between 3 to 10 centimeters (1 to 4 inches) in length and is typically 1 to 3 centimeters (0.5 to 1.25 inches) thick.

How are the spore-bearing structures on the underside of the cap described?

The underside of the cap is densely covered with small, slender, whitish spines that usually range from 2 to 7 millimeters in length. These spines sometimes extend down onto the stipe.

What color is the spore print of Hydnum repandum?

The spore print of Hydnum repandum is pale cream to white in color.

Describe the basidiospores of Hydnum repandum.

The basidiospores of Hydnum repandum are smooth, thin-walled, and translucent (hyaline). They are typically spherical to broadly egg-shaped and usually contain a single, large, refractive oil droplet.

What notable chemical compound has been identified in H. repandum, and what is its potential significance?

Hydnum repandum contains a diepoxide compound known as repandiol. This compound is currently under laboratory research to investigate its potential biological effects.

What types of compounds contribute to the fruity aroma of Hydnum repandum?

The characteristic fruity aroma of Hydnum repandum is attributed to volatile organic compounds, specifically derivatives of eight-carbon molecules, such as 1-octen-3-ol and related substances.

What radioactive isotope has been found to accumulate in H. repandum fruit bodies following the Chernobyl disaster?

Following the Chernobyl disaster, European studies indicated that the fruit bodies of Hydnum repandum exhibit a high capacity for accumulating the radioactive isotope caesium.

What are two species found in North America that resemble H. repandum?

Two species found in North America that bear resemblance to Hydnum repandum are the white hedgehog (Hydnum albidum) and the giant hedgehog (Hydnum albomagnum).

How does Hydnum umbilicatum differ from H. repandum in terms of cap shape and spore size?

Hydnum umbilicatum is distinguished from Hydnum repandum by its smaller cap size (3-5 cm wide) and its often umbilicate (navel-like depression) cap shape, sometimes with a hole in the center. Microscopically, its spores are larger and more elliptical than those of H. repandum.

In what types of environments does Hydnum repandum typically grow?

Hydnum repandum thrives in both coniferous and deciduous woodlands, typically growing on the ground or within leaf litter.

During which seasons can Hydnum repandum be found fruiting?

The fruiting period for Hydnum repandum generally occurs from summer through autumn.

How is Hydnum repandum listed in the Red Data Lists of some European countries?

In several European countries, Hydnum repandum is listed in their Red Data Lists; it is considered vulnerable in the Netherlands, Belgium, and Germany, while Sweden classifies it as Least Concern.

What is the approximate macronutrient breakdown of dried Hydnum repandum per 100 grams?

Dried Hydnum repandum contains approximately 56% carbohydrates, 4% fat, and 20% protein per 100 grams.

Which minerals are notably abundant in Hydnum repandum?

Hydnum repandum is particularly rich in certain dietary minerals, with copper and manganese being present in high amounts per 100 grams.

How is Hydnum repandum regarded from a culinary perspective?

Hydnum repandum is highly regarded as an edible mushroom, often praised for its sweet, nutty flavor and crunchy texture, with some culinary experts considering it comparable to chanterelles.

What is a recommended step to take immediately after harvesting H. repandum to maintain its quality?

To maintain quality and prevent soil from lodging between its spines, it is recommended to gently brush the cap and stipe of Hydnum repandum specimens immediately after harvesting.

What are some common ways to prepare Hydnum repandum for consumption?

Hydnum repandum can be prepared in various ways, including pickling, simmering in milk or stock, and sautéing, which contributes to its tender, meaty texture and mild flavor.

Is the texture of cooked Hydnum repandum suitable for preservation by freezing?

Yes, the firm texture of cooked Hydnum repandum makes it well-suited for preservation through freezing.

How can the potential bitterness of older Hydnum repandum specimens be reduced?

The bitterness that can develop in older specimens of Hydnum repandum can often be effectively reduced or removed by boiling the mushrooms.

Where is Hydnum repandum commonly sold alongside other mushrooms?

Hydnum repandum is frequently sold alongside chanterelles in Italy and is recognized as an edible species sold in markets in France.

What common woodland animal is known to consume Hydnum repandum?

The red squirrel (Sciurus vulgaris) is known to utilize Hydnum repandum mushrooms as a food source.

What does the image caption 'Detail of the spines' refer to?

The image caption 'Detail of the spines' refers to a close-up view of the characteristic spine-like structures on the underside of the Hydnum repandum mushroom's cap, which are responsible for bearing its spores.

What does the image caption 'At a market in Finland' indicate about the context of the mushroom?

The image caption 'At a market in Finland' suggests that Hydnum repandum is a mushroom that is commonly available and traded in markets within Finland, highlighting its culinary significance in that region.

What does the image caption 'Collection from Eggingen, Germany' signify?

The image caption 'Collection from Eggingen, Germany' indicates that the pictured specimens of Hydnum repandum were gathered from the Eggingen area in Germany, illustrating its geographical distribution.

What does the image caption 'Hydnum repandum, dried' illustrate?

The image caption 'Hydnum repandum, dried' indicates that the accompanying nutritional data pertains to the mushroom after it has undergone dehydration, a process that concentrates its nutrients.

What are taxon identifiers, and why are they important for species like Hydnum repandum?

Taxon identifiers are unique codes or names used in biological databases to catalog and reference specific species, such as Hydnum repandum. They are crucial for organizing scientific information and ensuring consistency across various resources.

What does the Latin term repandum mean in the context of the mushroom's name?

The Latin term 'repandum' in the species name Hydnum repandum translates to 'bent back' or 'wavy,' describing the characteristic shape of the mushroom's cap margin.

What does the varietal epithet album signify for Hydnum repandum?

The varietal epithet 'album' means 'white as an egg,' referring to the distinctive white color of the fruit bodies found in this particular variety of Hydnum repandum.

How do the fruit bodies of Hydnum repandum typically grow in relation to each other?

The fruit bodies of Hydnum repandum can grow individually, scattered, or in groups, and they are also known to form fairy rings. When clustered closely, their caps may develop distorted shapes.

With what type of organisms does Hydnum repandum form a mycorrhizal relationship?

Hydnum repandum forms a mycorrhizal relationship with trees, creating a mutually beneficial association where the fungus aids the tree in nutrient uptake.

What is the typical texture of the cap surface of Hydnum repandum?

The cap surface of Hydnum repandum is generally characterized as dry and smooth, although older specimens may exhibit cracking.

What are the typical colors observed for the stipe of Hydnum repandum?

The stipe of Hydnum repandum is usually white or matches the color of the cap, and it can sometimes be positioned off-center.

What is the meaning of the common name 'wood hedgehog' for Hydnum repandum?

The name 'wood hedgehog' for Hydnum repandum likely refers to the mushroom's habitat in woodlands and the presence of its spine-like structures, which resemble the quills of a hedgehog.

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Taxonomic Classification

Scientific Classification

Hydnum repandum, first described by Carl Linnaeus in 1753, is the type species of the genus Hydnum within the family Hydnaceae. Its classification reflects its unique characteristics within the fungal kingdom.

The hierarchical classification is as follows:

Kingdom: Fungi
Division: Basidiomycota
Class: Agaricomycetes
Order: Cantharellales
Family: Hydnaceae
Genus: Hydnum
Species: Hydnum repandum

Several synonyms and varieties have been described over time, reflecting ongoing taxonomic research and differing interpretations of morphological variations.

Naming and Evolution

The specific epithet repandum, meaning "bent back," refers to the wavy margin of the cap. The species has been reclassified into various genera throughout mycological history, including Hypothele, Dentinum, Tyrodon, and Sarcodon, before being firmly established as the type species for Hydnum.

Key taxonomic points:

Officially described by Carl Linnaeus in 1753.
Sanctioned by Elias Fries in 1821.
Molecular studies in the 2000s revealed complex genetic diversity, suggesting the existence of cryptic species within the broad concept of H. repandum.
Research indicates potential speciation events and host-plant associations, with genetic material found across continents and different tree hosts.

Morphological Description

Cap and Spines

The most distinctive feature of Hydnum repandum is its hymenium, which consists of small, delicate spines rather than gills or pores. The cap is typically 2–17 cm wide, dry, and ranges in color from yellow to light orange or brown, often developing an irregular shape, especially when growing in clusters.

Detailed cap and spine characteristics:

Cap: Dry, smooth surface, often irregular, convex to concave with maturity. Wavy margin, rolled inward when young. Color varies from pale yellow to light orange or tan. Can become cracked with age.
Spines: Densely cover the underside of the cap, measuring 2–7 mm long. They are whitish, slender, and sometimes decurrent (running down the stipe).
Bruising: All parts of the mushroom stain orange with age or when bruised.

Stipe and Flesh

The stipe (stem) is typically 3–10 cm long and 1–3 cm thick, often off-center. It is usually white or matches the cap's color. The flesh is thick, white, firm, and brittle, possessing a pleasant odor and a spicy or slightly bitter taste.

Further details on the stipe and flesh:

Stipe: 3–10 cm long, 1–3 cm thick. White or concolorous (same color as cap), sometimes off-center.
Flesh: Thick, white, firm, brittle. Bruises yellow to orange-brown.
Taste/Odor: Pleasant odor, spicy or bitter taste (bitterness can increase with age).

Spore Print and Microscopic Features

The spore print is a pale cream color. Microscopically, the spores are smooth, thin-walled, hyaline (translucent), and typically spherical to broadly egg-shaped. The presence of clamp connections in the hyphae is a notable microscopic feature.

Microscopic characteristics:

Spore Print: White to cream.
Basidiospores: Smooth, thin-walled, hyaline, 5.5–7.5 x 4.5–5.5 µm, usually containing a single large oil droplet.
Basidia: Club-shaped, four-spored, 30–45 x 6–10 µm.
Cap Cuticle: Trichodermium of narrow, club-shaped cells (2.5–4 µm wide).
Hyphae: Contain clamp connections.

Chemical Composition

Bioactive Compounds

Hydnum repandum contains unique compounds, including the diepoxide repandiol, which is being researched for potential biological effects. The mushroom's characteristic aroma is attributed to specific volatile organic compounds, primarily eight-carbon derivatives.

Key chemical constituents:

Repandiol: A diepoxide compound (2R,3R,8R,9R)-4,6-decadiyne-2,3:8,9-diepoxy-1,10-diol), under laboratory investigation for cytotoxic properties.
Volatile Organic Compounds: Contribute to the mushroom's aroma, including 1-octen-3-ol, (E)-2-octenol, and (E)-1,3-octadiene.

Radioactivity Accumulation

Following the Chernobyl disaster, studies indicated that Hydnum repandum fruit bodies exhibit a notable capacity for accumulating radioactive isotopes, particularly caesium, from their environment.

Environmental impact:

Post-Chernobyl studies in Europe showed high rates of caesium accumulation in H. repandum.
This highlights the mushroom's role as a bioaccumulator, sensitive to environmental contaminants.

Culinary Significance

Taste and Texture

Considered a choice edible mushroom, Hydnum repandum is praised for its sweet, nutty flavor and firm, crunchy texture, often compared favorably to chanterelles. It is widely recognized and sold in European markets.

Culinary attributes:

Flavor: Sweet, nutty, sometimes described as peppery or similar to oysters.
Texture: Firm and crunchy when cooked.
Comparison: Often considered a culinary equivalent to chanterelles.
Market Recognition: Officially recognized as edible in France and commonly sold with chanterelles in Italy.

Preparation Methods

Preparation involves gently brushing off soil to preserve the delicate spines. It can be pickled, simmered in milk or stock, or sautéed. The mushroom readily absorbs flavors, making it versatile in cooking. Older specimens may require boiling to mitigate bitterness.

Recommended preparation techniques:

Cleaning: Brush gently to remove soil; avoid washing if possible.
Cooking Methods: Pickling, simmering, sautéing.
Flavor Absorption: Absorbs surrounding flavors well.
Bitterness: Boiling can reduce bitterness in older specimens.
Storage: Suitable for freezing due to its firm texture.
Pest Resistance: Not typically infested by maggots, making it a reliable find.

Wildlife Consumption

Beyond human consumption, Hydnum repandum serves as a food source for wildlife, notably the red squirrel (Sciurus vulgaris), indicating its ecological importance.

Habitat and Distribution

Ecological Niche

As a mycorrhizal fungus, Hydnum repandum forms symbiotic relationships with trees. It thrives in the soil and leaf litter of both coniferous and deciduous forests, contributing to forest ecosystem health.

Ecological context:

Mycorrhizal Association: Forms symbiotic relationships with tree roots, facilitating nutrient exchange.
Habitat: Found on the ground or in leaf litter within coniferous and deciduous woodlands.
Growth Pattern: Fruits singly, scattered, or in groups; can form fairy rings.

Geographic Distribution

This species is widely distributed across Europe, being one of the most common tooth fungi. Its presence extends to parts of North America and Asia, though genetic studies suggest distinct species may exist within the broader H. repandum complex.

Geographic spread:

Europe: Widely distributed, common in various woodland types.
North America: Related species exist; H. repandum itself has a more limited distribution.
Asia: Found in regions including China and Japan.
Conservation Status: Listed as vulnerable in some European countries (Netherlands, Belgium, Germany) but of least concern in Sweden.

Nutritional Profile

Macronutrient Breakdown

Dried Hydnum repandum is a good source of carbohydrates and protein, with a moderate fat content. Its nutritional value per 100g highlights its potential as a dietary component.

Nutritional values per 100g (approximate, dried):

Energy: 1,431 kJ (342 kcal)
Carbohydrates: 56.1 g
Fat: 4.3 g
Protein: 19.7 g

Mineral Content

The mushroom is particularly rich in essential minerals, notably copper and manganese, which play vital roles in various bodily functions. It also provides significant amounts of calcium, iron, and magnesium.

Key minerals per 100g (approximate, dried):

Calcium: 600 mg (46% DV)
Copper: 38.9 mg (4322% DV)
Iron: 38 mg (211% DV)
Magnesium: 230 mg (55% DV)
Manganese: 23.2 mg (1009% DV)
Potassium: 2.89 mg (negligible %DV based on some recommendations)
Sodium: 31.9 mg (1% DV)
Zinc: 5.72 mg (52% DV)

^{*DV = Daily Value based on US recommendations.}

Fatty Acids and Other Compounds

The fatty acid profile is dominated by linoleic acid and oleic acid. It also contains plant sterols (mycosterol) and vitamins, though in smaller quantities.

Major fatty acids per 100g (approximate, dried):

Palmitic acid: 16%
Stearic acid: 1%
Oleic acid: 26%
Linoleic acid: 48%
Linolenic acid: 20%
Also contains plant sterols (mycosterol).

Distinguishing Features

Lookalikes

Hydnum repandum can be confused with similar species like Hydnum albidum, H. albomagnum, and H. umbilicatum. Key differentiators include cap shape, color variations, bruising reactions, and microscopic spore characteristics.

Key distinctions from similar species:

Hydnum albidum: White to pale yellowish-grey cap, bruises yellow to orange.
Hydnum albomagnum: Larger and paler than H. repandum.
Hydnum umbilicatum: Smaller caps (3–5 cm), often umbilicate (navel-like depression), larger and more elliptical spores (7.5–9 x 6–7.5 µm).
Hydnum rufescens: Generally smaller, with a deeper apricot to orange color.
Hydnum ellipsosporum: Smaller fruit bodies (3–5 cm caps), distinctively ellipsoid spores (9–11 x 6–7.5 µm).

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References

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Important Notice

This page was generated by an Artificial Intelligence and is intended for informational and educational purposes only. The content is based on a snapshot of publicly available data from Wikipedia and may not be entirely accurate, complete, or up-to-date.

This is not professional culinary or botanical advice. The information provided on this website is not a substitute for professional consultation regarding foraging, identification, or preparation of wild mushrooms. Always exercise extreme caution and consult with experienced local experts before consuming any wild fungi. Misidentification can lead to severe illness or death.

The creators of this page are not responsible for any errors or omissions, or for any actions taken based on the information provided herein.

Mycelial Mysteries

💡 Dive in with Flashcard Learning! 💡

Taxonomic Classification 🌳

🔬 Scientific Classification

📜 Naming and Evolution

Morphological Description 🍄

🍄 Cap and Spines

🌿 Stipe and Flesh

⚪ Spore Print and Microscopic Features

Chemical Composition 🧪

⚛️ Bioactive Compounds

☢️ Radioactivity Accumulation

Culinary Significance 🍽️

😋 Taste and Texture

🍳 Preparation Methods

🐿️ Wildlife Consumption

Habitat and Distribution 🌲

🌳 Ecological Niche

🌍 Geographic Distribution

Nutritional Profile 🍎

📊 Macronutrient Breakdown

💎 Mineral Content

💧 Fatty Acids and Other Compounds

Distinguishing Features 🔍

🆚 Lookalikes

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📜 Important Notice

Dive in with Flashcard Learning!

Taxonomic Classification

Scientific Classification

Naming and Evolution

Morphological Description

Cap and Spines

Stipe and Flesh

Spore Print and Microscopic Features

Chemical Composition

Bioactive Compounds

Radioactivity Accumulation

Culinary Significance

Taste and Texture

Preparation Methods

Wildlife Consumption

Habitat and Distribution

Ecological Niche

Geographic Distribution

Nutritional Profile

Macronutrient Breakdown

Mineral Content

Fatty Acids and Other Compounds

Distinguishing Features

Lookalikes

Teacher's Corner

True or False?

Test Your Knowledge!

Gamer's Corner

Discover other topics to study!

References

Feedback & Support

Disclaimer

Important Notice