Grifola frondosa

Description

Grifola frondosa is a fungus that grows in the same spot for many years, like the sulphur shelf mushroom. It mostly grows in the northeastern United States, but can also be found as far west as Idaho. The fruiting body can be as large as 100 cm (40 in), rarely up to 150 cm (60 in), and consists of multiple grayish-brown caps that are often curled or spoon-shaped with wavy edges. The stalk is milky-white and has a branchy structure that becomes tough as the mushroom matures. In Japan, the maitake can grow to over 45 kg (100 lbs). The caps have about one to three pores per millimeter, with the tubes rarely deeper than 3 mm (1/8 in).

To harvest Hen of the Woods mushroom, a large knife is necessary for cutting its thick stem and trimming off the lower fronds. A five-inch folding fillet knife can do the job. The lowest fronds covered in dirt should be discarded. The mushroom requires extensive cleaning, especially around the point where the cap becomes stem, where grit is often found. It's best to harvest the mushroom when young and tender with almost closed pores, as it is past its prime when the pores widen and become angular.

Hen of the woods is a delicious mushroom with a wild and woodsy flavor. It can be cooked in many ways and used in different dishes like pastas, stir-fries, and more. It is generally safe to eat, but some people may have allergic reactions. You can freeze it or dry it for long-term storage. When storing fresh hen of the woods, avoid plastic bags or closed containers and use paper bags or wax paper instead.

Common names: Hen of the Woods, Rams Head, Sheep's Head, Maitake, German (Klapperschwamm).

Mushroom Identification

1. Fruiting Body

   The fruiting body is 5.9 to 15.75 inches (15 to 40 cm) across and 3.94 to 11.81 inches (10 to 30 cm) high, composed of multiple caps in a rosette, sharing a branched, stem-like structure.

2. Individual Caps

   The individual caps are 1.18 to 5.5 inches (3–14 cm) across, more or less fan-shaped or deltoid, and dark to pale gray-brown (often with vague concentric zones). They are yellow with old age and are finely velvety or bald, with wavy margins.

3. Pore Surface

   The pore surface runs down the stem, often nearly to the base. It is lavender gray when young, becoming white and staining yellowish with age. It does not bruise and has 1–3 angular to slot-like or nearly tooth-like pores per mm, with tubes 1–3 mm deep.

4. Stem

   The stem structure is branched, whitish, and tough, often off-center.

5. Flesh

   The flesh is firm, white, and unchanging when sliced.

6. Odor and Taste

   The odor and taste are mild and pleasant.

7. Spore Print

   White.

8. Habitat

   This fungus is weakly parasitic on living oaks and other hardwoods, as well as saprobic on decaying wood. It causes a white butt rot and can be found fruiting near the bases of trees. It often reappears in the same location in subsequent years and is widely distributed east of the Rocky Mountains, but rare in the west. It is typically found in late summer to early autumn. It is native to China, Europe, and North America.

9. Chemical Reactions

   KOH is negative on flesh and surfaces, and iron salts are negative on the cap and flesh.

10. Microscopic Features

    The spores are 4–6 x 3–4 µm, ellipsoid, smooth, hyaline in KOH, often with one large oil droplet, and inamyloid. The basidia are 25–30 x 6–8 µm, clavate, and 4-sterigmate. Hymenial cystidia are not found. The hyphal system is dimitic, and clamp connections are present on generative hyphae but absent on skeletal hyphae.

Look-Alikes

1. Meripilus giganteus

   Grows in a rosette pattern at the base of oaks, primarily with fan to spoon shaped caps or fronds. The caps of Meripilus giganteus usually stain black with handling, while hen of the woods caps do not stain. This characteristic can be used to distinguish the two species.

2. Polyporus umbellatus

   Grows from an underground tuber-like sclerotium about the size of a potato.

Health Benefits

1. Immune boosting

   Studies have found that supplementing with Maitake can help strengthen the immune system. This seems to be a fairly common trait among medicinal mushrooms, Maitake included. Who doesn't want to get sick less often?!

2. Hypotensive

   This means that by incorporating Maitake into your daily routine, you can decrease your blood pressure! This mushroom has been shown to lower blood pressure in people with high blood pressure who consume it regularly.

3. Hypoglycemic

   Not only does it lower your blood pressure, but Maitake can even lower your blood sugar! An excellent 1-2 punch for people who deal with rising blood pressure and diabetes, conditions that often go hand-in-hand. Adding some Maitake may hold off rising doses of medications and help contribute to fewer side effects.

4. Regulates Cholesterol

   Regular intake of Maitake has been shown to increase HDL cholesterol (the good stuff), and decrease LDL cholesterol (the bad stuff). Interestingly enough, it is speculated that it does this indirectly, through a beneficial effect on the gut microbiota. The gut microbiota is a term used to describe all the bacteria that make up the digestive system. It has been a focus point of a lot of research recently and we are discovering more and more about how keeping our microbiota happy keeps our body happy. Another point for Maitake!

5. Anti-tumour Properties

   That's right, supplementing with Maitake has been shown to put a stop to tumour formation. A lot of research in this area is currently focused on breast cancer, where this mushroom seems to help the most. Interestingly enough, the anti-tumour properties of this mushroom appear to be destroyed when heat is added. So if this is the benefit you are looking for, make sure to avoid mixing this mushroom into any coffees or teas!

6. Helps Eliminate Mercury from the Body

   Mercury is a heavy metal that use to be used in thermometers before we discovered how toxic it is. Now, the most common sources of mercury that people will encounter come from the sea, in the form of large fish species that we consume, like tuna. Having elevated levels of mercury in the body can cause symptoms such as anxiety, irritability, numbness, memory problems, depression and tremors. Fortunately, including Maitake in your diet can help reduce this build up and help you live a happier, healthier life!

How to Grow Grifola frondosa

Growing Grifola frondosa, or Maitake, can be a rewarding and fulfilling experience. Here is a step-by-step guide on how to grow this mushroom at home:

1. Obtain the spawn

   Grifola frondosa spawn can be purchased from a reputable supplier online or at a local mushroom farm. Alternatively, you can make your spawn by inoculating sterilized rye or wheat berries with spores from a mature mushroom.

2. Choose a growing medium

   Grifola frondosa can be grown on a variety of substrates such as sawdust, hardwood chips, or straw. Hardwood sawdust is a common choice for home growers.

3. Sterilize the growing medium

   Once you have chosen your growing medium, it must be sterilized to prevent contamination. This can be done by pressure-cooking the substrate or baking it in the oven.

4. Inoculate the substrate

   After the substrate has cooled, mix in the Grifola frondosa spawn. The spawn can be spread evenly throughout the substrate or layered on top.

5. Incubate the spawn

   The inoculated substrate should be kept in a sterile environment with consistent temperature and humidity. This can be achieved by using a grow tent or a clean room. The mycelium will begin to colonize the substrate over the next few weeks.

6. Transfer to fruiting containers

   Once the mycelium has fully colonized the substrate, it can be transferred to fruiting containers such as plastic bags or buckets. Poke small holes in the container to allow for air exchange.

7. Induce fruiting

   To induce fruiting, the substrate should be exposed to cooler temperatures (around 60-65°F) and higher humidity (above 80%). This can be achieved by misting the containers regularly or using a humidifier.

8. Harvest the mushrooms

   Grifola frondosa mushrooms will begin to grow within a few weeks of inducing fruiting. Once they reach maturity, harvest them by cutting them at the base with a clean knife.

9. Repeat the process

   Grifola frondosa can be grown in cycles, meaning you can reuse the same substrate multiple times to produce additional crops.

Growing Grifola frondosa can be a fun and rewarding hobby, but it requires careful attention to detail and a sterile environment to prevent contamination. By following these steps, you can enjoy a bountiful harvest of delicious and nutritious Maitake mushrooms.

Recipe: Seared Maitake Mushrooms

LEEK RéMOULADE

1. 1 leek, white and pale-green parts only, thinly sliced

2. Kosher salt

3. ½ small shallot, finely chopped

4. 2 cornichons, finely chopped

5. ⅓ cup vegan or regular mayonnaise

6. 2 Tbsp. Dijon mustard

7. 1 Tbsp. capers, finely chopped

8. 1 Tbsp. chopped fresh dill

9. 1 Tbsp. chopped fresh tarragon

10. Freshly ground black pepper

MUSHROOMS

1. 2 garlic cloves, finely chopped

2. 2 Tbsp. plus ½ cup olive oil

3. 2 8-oz. maitake mushrooms, cleaned, halved through the stem

4. Kosher salt and freshly ground black pepper

LEEK RéMOULADE

1. Cook leek in a small saucepan of boiling salted water until tender, about 4 minutes. Drain; transfer to a colander set in a bowl of ice water. Let cool; drain and transfer to paper towels.

2. Mix shallot, cornichons, mayonnaise, mustard, capers, dill, tarragon, and 3 Tbsp. water in a small bowl, adding more water as needed to thin. Fold in leek; season with salt and pepper.

MUSHROOMS

1. Combine garlic and 2 Tbsp. oil in a small bowl. Heat remaining ½ cup oil in 2 large skillets over medium-high heat. Season mushrooms with salt and pepper.

2. Cook each, cut side down, in a skillet, pressing to flatten once they begin to soften, until golden and crisp, about 3 minutes per side. Reduce heat to low.

3. Drizzle garlic mixture around mushrooms and cook until garlic is golden, about 1 minute; turn mushrooms to coat.

4. Spoon leek rémoulade onto plates and top with mushrooms.

Recipe: Grilled Thai Marinated Maitake Mushrooms

Grill about 3-5 minutes on each side for the perfect side dish.

Ingredients

1. 2 pounds Maitake mushrooms

2. 3/4 cup olive oil

3. 1/4 cup tamari

4. 6 wild leeks - cut into small pieces, or you could use scallions in a pinch

5. 3 tablespoons maple syrup

6. 1 teaspoon curry powder

7. 3 tablespoons white wine - dry, such as chardonnay

8. 1/4 teaspoon sea salt

9. 1/8 teaspoon ground black pepper

Instructions

1. Clean the maitake's by quickly running them underwater. Set on paper towels to drain.

2. Slice in 3/4" thick slices and layout in a casserole dish or two for marinading.

Making the marinade:

1. Add all of the marinade ingredients to a blender.

2. I forgot to mention that I got the wild leeks (ramps) from Whole Earth Harvest too!

3. Blend until everything is smooth and completely blended. It only takes about a minute.

4. Pour the marinade evenly over the prepared mushrooms.

5. Cover the casserole with plastic wrap and place in the refrigerator for at least 4 hours.

6. When ready to cook grill over medium-high heat for 3-5 minutes on each side.

7. Ready to eat!

Recipe: Maitake Wild Rice Salad

Ingredients

1. ½ cup raw walnut pieces

2. 2 tablespoons extra virgin olive oil

3. 2 tablespoons finely chopped yellow onion

4. 6 ounces maitake mushrooms, roughly chopped

5. 1 teaspoon fresh lemon juice

6. ¾ teaspoon fine sea salt

7. ¼ teaspoon ground black pepper

8. 1 cup dry wild rice, cooked according to package directions and cooled

9. 1 tablespoon chopped fresh chives

Instructions

1. Toast the walnut pieces over medium-high heat in a large, dry skillet. Stir often and cook for 3 minutes, or until you begin to smell their nutty aroma. Remove from the heat and transfer the nuts to a bowl to cool.

2. Add the olive oil to the skillet and return it to medium heat. Add the onions. Cook, stirring often for 1 minute. The onion will begin to turn golden brown in spots as it cooks in the oil. Stir in the mushrooms and cook for about 2 minutes. They will soften and shrink, but still, have a somewhat firm bite. Stir in the walnuts and cook for another 30 seconds.

3. Remove the skillet from the heat and add the lemon juice, salt, and pepper. Stir well and let cool to room temperature.

4. Transfer the rice to a large bowl. Add the mushrooms. Toss to mix the ingredients. Sprinkle with chives before serving at room temperature or chilled.

Recipe: Roasted Maitake Mushrooms with Seaweed Butter

Ingredients

1. 1/2 cup dried wakame seaweed (1/2 ounce)

2. 1 cup boiling water

3. 1 stick unsalted butter, at room temperature

4. Kosher salt

5. Pepper

6. 1 1/4 pounds whole heads of maitake (also known as hen-of-the-woods) mushrooms

7. 1/4 cup extra-virgin olive oil

8. 2 tablespoons chopped chives

9. Lemon wedges, for serving

Instructions

1. In a small bowl, cover the seaweed with the boiling water and let stand until pliable, about 30 minutes. Drain and chop the seaweed; transfer to a bowl. Stir in the butter and season with salt and pepper.

2. Preheat the oven to 425°. Arrange the mushrooms on a rimmed baking sheet in a single layer. Drizzle with the olive oil, season generously with salt and pepper, and toss to coat. Dollop three-fourths of the seaweed butter over the mushrooms. Roast for about 30 minutes, basting occasionally, until tender, deeply golden and crispy in spots.

3. Scrape the mushrooms and crispy seaweed onto a serving platter and top with the chives. Serve with lemon wedges and pass the remaining seaweed butter at the table.

Recipe: Maitake Mushrooms with Thyme and Sherry

Ingredients

1. 3 pounds maitake mushrooms (or cremini or morels, or a mix)

2. Kosher salt to taste

3. 1/2 cup unsalted butter (at room temperature), divided

4. 8 to 10 branches fresh thyme

5. 1/4 cup sherry, preferably Amontillado

6. About 1 tbsp. lemon juice

7. About 1 tbsp. Champagne vinegar

8. Chopped fresh chives or parsley

Instructions

1. Brush mushrooms clean and trim bottoms of stems. Tear clusters into large chunks.

2. Heat two large heavy (not nonstick) frying pans over medium-high heat 2 minutes. Divide mushrooms between pans and season lightly with salt. Cook until starting to release liquid, about 7 minutes. If mushrooms are very dry, add a splash or two of water.

3. Add 1 1/2 tbsp. butter and 4 or 5 branches thyme to each pan. Cook mushrooms, turning occasionally, until nicely browned, about 5 minutes. Add another 1 1/2 tbsp. butter to each pan and cook until tender, 7 to 10 minutes.

4. Into each pan, swirl 2 tbsp. sherry, then 1 tbsp. butter and 1 1/2 tsp. each lemon juice and vinegar. Cook over high heat, stirring occasionally, until sauce is glossy and mushrooms are coated, 2 minutes. Stir in a few tbsp. water as needed to loosen sauce. Season to taste with salt and more vinegar. Remove thyme.

5. Pour mushrooms into a serving dish and top with chives.

6. Make ahead: Through step 3, up to 1 day, chilled airtight in 1 pan. To reheat, add a few tbsp. water and heat gently in pan.

Recipe: Sautéed Maitake Mushrooms with Red Chiles and Cilantro

Ingredients

1. 1⁄4 cup plus 2 tbsp. vegetable oil

2. 10 dried chiles de árbol

3. 8 whole star anise

4. 2 lb. maitake mushrooms, torn in half by hand into large 3–4-inch pieces

5. 2 tbsp. minced ginger

6. 1 tbsp. plus 1 tsp. minced garlic

7. 1⁄4 cup soy sauce

8. 2 tbsp. vegetable stock

9. 1 tbsp. plus 1 tsp. packed light brown sugar

10. 1⁄2 cup loosely packed cilantro leaves

11. 3 scallions, thinly sliced crosswise on the bias

Instructions

1. In a large wok or high-sided skillet, heat the oil until it begins to smoke. Stir in half the chiles and star anise and toss in the oil until fragrant, about 20 seconds. Add half the mushrooms in a single layer, toss in the oil, and cook, undisturbed, until caramelized and crisp on the bottom, about 4 minutes. Toss again and cook, undisturbed, until caramelized and crisp, about 2 minutes more.

2. Using a slotted spoon, remove the mushrooms, chiles, and star anise from the wok and transfer to a plate. Return the wok to the heat and repeat with the remaining chiles, star anise, and mushrooms.

3. Return all the chiles, star anise, and mushrooms to the wok along with the ginger and garlic and cook, tossing, until fragrant, about 30 seconds. Pour in the soy sauce, stock, and sugar and cook, tossing, until the sugar dissolves and the garlic and ginger are tender, about 1 minute. Transfer the mushrooms, spices, and chiles to a large serving platter and sprinkle with the cilantro and scallions before serving.

Recipe: Maitake Mushroom Alfredo Pasta

Ingredients

1. ½ pound pasta of choice (I used porcini trumpets)

2. 3 tablespoons extra-virgin olive oil, divided

3. 12 ounces maitake mushrooms

4. Kosher salt, to taste

5. Freshly cracked black pepper, to taste

6. 4 cloves garlic, chopped

7. 2 tablespoons diced shallots

8. 1 cup dry white wine

9. ¾ cups crème fraîche

10. ¼ cup grated Parmesan, plus additional for serving

11. 1 tablespoon chopped flat-leaf parsley

12. ½ teaspoon chopped thyme leaves

Instructions

1. Bring a large pot of water to a boil over medium-high heat. Add the pasta and cook, stirring occasionally, until al dente, about 8 minutes. Drain the pasta and return to the pot.

2. Heat a large sauté pan over medium heat, add two tablespoons of the olive oil and heat through. Add the mushrooms and sauté until golden brown, about 3 minutes (working in batches if you have to so you don’t overcrowd the pan). Remove to a bowl and set aside.

3. Return the pan to medium heat, add the remaining olive oil and heat through. Add the garlic and shallots and cook, stirring occasionally, until the shallots are tender, about 3 minutes. Add the wine and let it reduce by about half, about 4 minutes. Whisk in the crème fraîche until combined and let cook until slightly thickened, about 5 minutes. Stir in the Parmesan followed by the parsley and thyme then season with salt and pepper.

4. Add the sauce and the mushrooms to the pasta and stir to combine. Serve topped with additional Parmesan cheese.

Recipe: Seared Pancetta Maitake Mushrooms

Ingredients

1. 1/2 pound maitake (or any wild mushrooms of your choice)

2. 1 ounce ground pancetta

3. 1 tablespoon duck fat

4. Garnish with parsley, sea salt, and chili pepper flakes

Instructions

1. Clean, dry and tear apart the mushrooms.

2. Heat a cast iron pan over medium heat, and cook pancetta until fat has rendered and pancetta is crumbly (break apart with a wooden spoon). Remove pancetta, set aside, leaving fat behind.

3. Add duck fat to the pan and increase heat to medium-high. When fat is slightly smoking, add mushrooms to the pan and cook undisturbed for about 3-5 minutes until golden. Flip and cook the other side for about a minute or so.

4. Transfer to serving dish, sprinkle on minced parsley, sea salt, chili pepper flakes and crispy pancetta crumbs.

Recipe: Maitake Mushroom Soup

Ingredients

1. 4 ounces maitake (hen of the woods) mushrooms (chopped)

2. 1/2 ounce dried shiitake mushrooms (soaked in 1 cup hot water)

3. 1/2 pound assorted fresh mushrooms (preferably creminis mixed with at least 6 ounces shiitakes)

4. 3 tablespoons olive oil

5. 2 large shallots (chopped)

6. 1 small leek (chopped)

7. 1 small Vidalia onion (chopped)

8. 1 stalk celery (chopped)

9. 1 carrot (chopped)

10. 1 medium potato (peeled and chopped)

11. 4 cups vegetable stock (water or chicken stock)

12. 2 tablespoons tamari

13. 1 tablespoon cognac (optional)

14. 1 bay leaf

15. 2 teaspoons chopped fresh thyme

16. 1 teaspoon chopped fresh rosemary

17. Sea salt

Instructions

1. Drain the shiitake mushrooms and reserve the liquid. Chop all the mushrooms. Heat oil over medium flame in a soup pot.

2. Add mushrooms to pot along with shallot, leek, onion, celery, carrot, and potato. Increase heat to medium-high, and cook vegetables, stirring often, until they begin to soften, about ten minutes.

3. Add soaking liquid from mushrooms, stock, tamari, cognac, and bay leaf. Bring to a boil, reduce heat, and simmer 30 minutes.

4. Add thyme and rosemary, and puree with a vertical hand blender until smooth.

5. Season to taste and simmer an additional 5 minutes.

Recipe: Grifola frondosa Papardelle

Ingredients

1. 1.25 ounces dried Porcini mushrooms

2. 8 ounces dried or 12 ounces fresh papardelle (wide) noodles

3. 6 tablespoons unsalted butter

4. 2 tablespoons olive oil

5. 1 shallot, minced

6. 1/2 teaspoon red pepper flakes

7. 1 large Maitake (also called Hen of the Woods) mushroom (about 3.5 ounces), trimmed and petals separated

8. 1 tablespoon lemon juice

9. 1 tablespoon fresh chopped parsley, plus more for topping

10. Salt and freshly ground black pepper, to taste

11. 1/2 cup (2 ounces) grated pecorino cheese

Instructions

1. Place dried mushrooms in a bowl with 2 1/2 cups very hot water. Set aside and let soften for 30 minutes. Drain, reserving leftover liquid. Coarsely chop mushrooms.

2. Bring a large pot of salted water to a rolling boil. Cook pasta according to package directions if using dried noodles, or approximately 4 to 5 minutes for fresh noodles, or until just al dente. You want the pasta to be done at about the same time as the mushroom sauce, so time your cooking accordingly.

3. Melt butter together with olive oil in a large saucepan over medium-high heat. When butter is melted and frothy, add shallot and red pepper flakes and saute until softened, about 3 minutes. Add rehydrated mushrooms and cook, stirring occasionally, for about 3 more minutes. Reduce heat to medium and add Maitake mushroom pieces, stirring until slightly softened and coated in butter, about 2 minutes. Stir in lemon juice and 1/4 cup of reserved mushroom liquid; season with salt and pepper.

4. Add drained noodles to pan with mushrooms, sprinkle parsley over top, and gently toss until noodles are coated and have absorbed some of the liquid, 1 to 2 minutes. Divide among serving bowls, top with a generous sprinkling of pecorino cheese and more parsley (if desired), and serve immediately.

History

James J Dickson, a mycologist from Scotland, gave this polypore its first scientific name, Boletus frondosus, in 1785. Later, Samuel Frederick Gray, a Briton, transferred it to the genus Grifola in 1821, giving it the scientific name we use today, Grifola frondosa. The name frondosa means "having fronds", referring to the mushroom's leaf-like shape.

Video

Synonyms and Varieties

• Boletus ramosissimus Schaeffer (1774), Fungorum qui in Bavaria et Palatinatu circa Ratisbonam, 4, p. 85, tab. 127-129

• Agaricus ramosus Lamarck (1783), Encyclopédie méthodique, Botanique, 1, p. 51

• Boletus frondosus Dickson (1785), Plantarum cryptogamicarum britanniae, 1, p. 18 (Basionyme) Sanctionnement : Fries (1821)

• Boletus intybaceus Baumgarten (1790), Flora lipsiensis, p. 631

• Polyporus multiconcha Paulet (1808) [1793], Traité des champignons, 2, p. 121, tab. 30, fig. 1-4

• Polyporus frondosus (Dickson) Fries (1821), Systema mycologicum, 1, p. 355

• Polyporus giganteus Hornemann (1823), Flora danica, 30, p. 12, tab. 1793 (nom. illegit.)

• Polyporus barrelieri Viviani (1834), I funghi d'italia e principalmente le loro specie mangereccie, velenose, o sospette, p. 28, tab. 28

• Polyporus intybaceus Fries (1838) [1836-38], Epicrisis systematis mycologici, p. 446

• Merisma intybaceus (Fries) Gillet (1877), Les hyménomycètes, ou description de tous les champignons (fungi) qui croissent en France, p. 692

• Merisma frondosus (Dickson) Gillet (1877), Les hyménomycètes, ou description de tous les champignons (fungi) qui croissent en France, p. 692

• Polypilus intybaceus (Fries) P. Karsten (1882), Bidrag till kännedom af Finlands natur och folk, 37, p. 25

• Polypilus frondosus (Dickson) P. Karsten (1882), Bidrag till kännedom af Finlands natur och folk, 37, p. 25

• Cladomeris frondosa (Dickson) Quélet (1886), Enchiridion fungorum in Europa media et praesertim in Gallia vigentium, p. 168

• Cladomeris intybacea (Fries) Quélet (1886), Enchiridion fungorum in Europa media et praesertim in Gallia vigentium, p. 168

• Caloporus intybaceus (Fries) Quélet (1888), Flore mycologique de la France et des pays limitrophes, p. 406

• Caloporus frondosus (Dickson) Quélet (1888), Flore mycologique de la France et des pays limitrophes, p. 406

• Grifola frondosa f. intybacea ( Fries) Pilát (1934), Beihefte zum botanischen centralblatt, zweite abteilung, 52, p. 33

• Grifola intybacea (Fries) Imazeki (1943), Bulletin of the Tokyo science Museum, 6, p. 98

• Polypilus frondosus var. intybaceus(Fries) Bondartsev (1953), Bracket Fungi Europ. USSR & Caucasus, p. 605

Photo sources:

Photo 1 - Author: Michel Langeveld (CC BY-SA 4.0)

Photo 2 - Author: Pethan at Dutch Wikipedia (CC BY-SA 3.0)

Photo 3 - Author: Michel Langeveld (CC BY-SA 4.0)

Photo 4 - Author: Sinisa Radic (CC BY-SA 4.0)

Photo 5 - Author: Sinisa Radic (CC BY-SA 4.0)