Agaricus campestris

Description

Agaricus campestris is a widely eaten gilled mushroom closely related to the cultivated button mushroom Agaricus bisporus. It is usually found in fields or pastures, especially those rich in manure and grassy areas after rain from late summer onwards worldwide. The largest fruitings tend to occur when warm and wet weather coincide. It is a stocky, medium-sized, clean white mushroom with bright pink gills when young. However, as it ages it tends to become brown overall with dark chocolate gills. They can appear in small groups, in fairy rings or just solitary.

The cap may be somewhat fibrillose to scaly and, typically, the cuticle extends past the margin, like an overhanging table-cloth. The ring usually is thin and not persistent, and the base of the stipe often is tapered. It occurs nearly worldwide.

It can be eaten sauteed or fried, in sauces, or even sliced raw and included in salads. However, it is not commercially cultivated due to its fast maturing and short shelf-life. This species can be mistaken for the deadly toxic destroying angel, so it is important to be careful when foraging for mushrooms.

A. campestris has been used in the past for treating ulcers, bed sores, scalds, and burns. Ongoing research is exploring its potential for enhancing the secretion of insulin and having insulin-like effects on glucose metabolism in vitro.

Common names: Field Mushroom, Meadow Mushroom, Pink Bottom, German (Wiesenchampignon), Netherlands (Gewone weidechampignon), Sweden (ängschampinjon), Latvia (Lauka atmatene).

Mushroom Identification

1. Cap

   0.98 to 3.94 inches (2.5 to 10 cm) broad, convex, broadly convex in age, often with a low umbo; margin incurved, decurved to occasionally upturned in senescent specimens; surface dry, smooth, fibrillose to finely scaled in dry weather; color: white to ashy-gray; context white, thick, unchanging when bruised or in KOH; odor and taste mild.

2. Gills

   Close, free, pink, becoming blackish-brown at maturity.

3. Stem

   1.18 to 2.36 inches (3 to 6 cm) long, 0.39 to 0.79 inches (1 to 2 cm) thick, tapering to a pointed base, stuffed; veil thin, membranous, fragile, either leaving remnants on the young cap margin or forming a median to superior, evanescent ring.

4. Spores

   Spores 5.5-8.0 x 3.5-5 µm, elliptical and smooth.

5. Spore Print

   Blackish-brown.

6. Habitat

   Saprobic, on soil among grass in pastures, playing fields and parks.

7. Season

   June to October.

Look-Alikes

1. Amanita virosa

   The most dangerous toxic confusion.

2. Agaricus xanthodermus

   A less serious, but more common, causes gastrointestinal problems in many people.

3. Agaricus bitorquis

   Has a thin double ring. It prefers dry and compacted areas near pathways.

4. Agaricus arvensis

   Typically bigger than the Field Mushroom. Although it starts with a similar white cap, it turns yellowish as it matures.

Here’s some general information and tips that should help you avoid bad guys, the most important things to notice are their smell and if they discolor when cut:

1. Cut the stem of the mushroom, then wait 15 minutes. If the cut stains yellow, throw it out!

2. Put the underside of the mushroom's cap close to your nose and smell it deeply. Is it mushroomy and good smelling? Great. Does it smell like embalming fluid? Bad.

3. There will be a ring right around the middle of the stem.

4. Pay close attention to the size of the mushrooms, if some are young and older growing together, make note of their sizes throughout their life span. These mushrooms are usually large, like portobellos from your grocery store when mature, when small, they will be about the size of a cultivated white button.

Cultivation Tips

Phase I

Combine compost ingredients on a concrete foundation, watering and turning ingredients to mix them. Turn the pile every daily for up to 15 days until the straw softens.

Compress the compost, adding poultry manure or other nitrogen supplements. Add gypsum to keep bits of straw from sticking together.

Add water and nitrogen supplements to the compost “rick” until its internal temperature rises above 155 degrees Fahrenheit. The compost is ready when it absorbs water, gives off a strong smell of ammonia, and is a uniform, caramel color.

Phase II

Spread the pile out and cool it to begin the pasteurization process.

Place the compost on trays or in plastic sleeves made from black lawn bags. Raise the air temperature to 140 degrees Fahrenheit for two hours to kill the ammonia-producing bacteria.

Ventilate the area for up to four days, dissipating ammonia until you can no longer smell it. Do not allow the inner temperature of the compost to drop more than 5 degrees Fahrenheit in 24 hours.

Spawning

Scatter spawn, a combination of mushroom spores and sterilized grains, over the surface of the compost.

Keep a constant temperature of 75 to 77 degrees Fahrenheit in the room where you keep the growing tray. The compost will generate heat but cool the air to keep its temperature from rising above 80 to 85 degrees Fahrenheit. Higher temperatures will kill mycelia, the first growth of the spores, and reduce yield.

Add supplements, treated slow-release soybean meal or other protein, to fuel the spawn’s development for two to three weeks. Subsiding heat in the pile signals the completion of spawning and the beginning of colonization.

Casing

Cover the colonized compost with a uniform 1 1/2- to 2-inch layer, called casing to make a mushroom-growing medium. Make your casing with pasteurized sphagnum moss peat and add enough garden lime to raise its pH to 7.5.

Darken the room - A. bisporus requires darkness to grow.

Maintain high humidity around the casing and compost tray by spraying with a hose attachment or spray bottle several times a day. Avoid overhead watering, which can cause the casing to clump.

Pinning and Cropping

Lower the temperature in the room to between 60 and 66 degrees Fahrenheit once bits of fungus begins forming in little bumps, called pins, on the surface of the casing.

Maintain high humidity and keep the lights off while mushrooms begin to pin.

Begin harvesting mushrooms two to three weeks after casing, as they become recognizable as mature mushrooms. During this “breaking” period, mushrooms double in size every day.

Things You Will Need

1. Mushroom compost, spawn, casing and supplements

2. Compost turner

3. Garden spades and hand trowels

4. Cement wharf

5. Growing trays or heavy black plastic bags

6. Oven or heat lamp

7. Fans or air conditioners

8. Spray attachment or spray bottle

Tips

1. Harvest mushrooms as they mature in waves, or flushes. Water casing gently several times per week while flushes and harvests continue.

2. Mushroom compost consists of wheat straw and horse manure. Other ingredients may be hay, corn cobs, cocoa bean hulls, or cotton seed hulls. Poultry manure or dried brewer's grain add nitrogen. Compost, spawn, casing and supplement production can be complex for beginners; all are available in kits and from agricultural suppliers.

Warnings

1. Sterilize instruments, time steps, and control temperature to prevent the growth of dangerous bacteria in compost.

2. Keep the compost base aerated; inhibiting air and water circulation slows the composting process, which provides the food for the crop. A concrete foundation allows air to infiltrate the bottom of the pile.

Life Cycle

1. Mycelial Growth Stage

   The life of Agaricus campestris begins with spores. Each spore has a germ pore, a circular indentation in one end of the spore. From this pore, a haploid strand called a hypha will grow. Spores will enter the growth medium (soil, logs, etc.) and the hypha will grow, branching to form mycelium, a web of cells beneath the surface of the ground.

2. Hypha Growth Stage

   The hypha is haploid, meaning they have exactly half of the chromosomes necessary to form a mushroom. When two genetically compatible hypha come in contact, the cell walls of each hypha dissolve and fuse together, combining their genetic material into one cell. From then on, any growth from these cells will also contain two nuclei, and will be dikaryotic, having a full set of chromosomes. These cells continue to form mycelium. This mycelium, however, is now capable of forming the fruiting bodies that we commonly call mushrooms.

3. Fruit Body Stage

   Most mushroom species, including A. bisporus, will take several weeks to grow fruiting bodies. Immediately before fruiting bodies develop, nuclei within the dikaryotic cells begin to replicate in large numbers. Then the cells will divide rapidly, forming the fruiting bodies. As they grow, they will erupt from the growth medium as a bud, eventually forming a mushroom. This is typically the stage in the life cycle of A.bisporus when they are harvested for human consumption.

4. Basidia Development Stage

   As the mushroom matures, it will develop a stem and cap. Under the cap, gills will form. As the gills mature, bubble-like cells called basidia will grow in the gill slits. These cells have two nuclei. The nuclei will eventually merge to form a single diploid nucleus. This will then reproduce through meiosis to form four haploid daughter cells.

5. Spore Development Stage

   Projections called sterigmatae will then develop. The nuclei within the daughter cells will then migrate through this growth and form four spores at the tip. The spores wait at the end of the sterigmata until they are physically dislodged. The spores are then released from the mushroom, falling to the ground to begin the life cycle again.

Health Benefits

1. Anti-oxidant

   Oxidative stress and damage can lead to a progression of diseases such as cancer. Hydrogen peroxide is one of the most aggressive of the free radicals that can cause cellular damage and Agaricus campestris was shown in the presence of hydrogen peroxide to reduce the cellular damage and death of cells they were exposed to. Providing an important natural possibility for oxidative damage protection.

2. Anti-cancer

   The cytotoxic effect of Agaricus campestris was evaluated using cancer cells for larynx carcinoma (HEp-2) and breast carcinoma (MCF-7). When compounds were extracted using hexane as the solvent, a cytotoxic potential was observed indicating its ability to cause cell death in these cancer lines in vitro.

3. Anti-diabetic

   Early studies looking at insulin release from rat pancreas islet cells show that Agaricus campestris stimulated the release of secretions that regulate blood glucose levels by having opposing effects – insulin and glucagon Insulin and glucagon reduce and increase blood glucose levels respectively. Administration of Agaricus campestris to a diabetes-induced mouse model in both drinking water and diet led to a decrease in the induced hyperglycaemia. By day 12, the levels were very similar to those of the non-diabetic control mice. The dose was 62.5 g/kg of diet and 2.5 g/l in place of drinking water. Glucose uptake and metabolism is dysfunctional in diabetes and in vitro, Agaricus campestris increased both glucose uptake and stimulated conversion to glycogen (glucogenesis). The results using Agaricus campestris alone were not dissimilar to those when Agaricus campestris was administered in conjunction with insulin.

4. Anti-microbial

   Resistance to antibiotics by pathological microorganisms requires alternative treatments. A methanol-derived extract of Agaricus campestris was examined for its anti-microbial activity. The study showed inhibition of growth of Bacillus subtilis, Proteus vulgaris, Pseudomonas aeruginosa and Candida albicans. Another study confirmed wild Agaricus campestris showed inhibition against growth of the food born gram-positive bacterium, Clostridium perfringens.

Recipe: Fennel & Meadow Mushroom Salad

Ingredients

1. Sliced fennel root - 2 c

2. Cooked meadow mushroom (Agaricus campestris) - 1 c sliced

3. Coarsely chopped fresh parsley - ½ c

4. Quartered roma tomatoes - 2 c

5. Thinly sliced red onion - 1/3 c

6. Olive oil - 2 T

7. Dark sesame oil - 1 T

8. White wine vinegar - 4 T

9. Balsamic vinegar - 2 T

10. Pinch of ground rosemary

11. Salt and pepper to taste

Instructions

1. Combine and lightly toss the vegetables.

2. Whisk together the oils, vinegars, and spices.

3. Pour over the vegetables and marinate at room temperature for one hour before serving.

4. Serves 6 as a side dish.

Recipe: Provencal Mushrooms

Ingredients

1. 1 pound meadow mushrooms or regular button mushrooms

2. 1/2 cup minced onion

3. Salt and black pepper

4. 2 tablespoons olive oil

5. 3 garlic cloves, minced

6. 1/4 cup chopped parsley

7. Lemon juice to taste

Instructions

1. Wipe the mushrooms clean with a damp paper towel or cloth. Slice thickly and put in a large saute pan. Set the pan over medium-high heat. Soon the mushrooms will begin to sizzle. Shake the pan often to keep the mushrooms moving in the pan. After a couple of minutes, they will begin to release their water. Sprinkle a healthy pinch of salt over them now and add the minced onion. In a few more minutes the mushrooms and onion will be bathing in boiling mushroom water. Let this boil until the liquid is almost all gone.

2. Add the olive oil and toss to coat. Saute until everything begins to brown a bit at the edges, then add the garlic and a little black pepper. Cook another 90 seconds, then add the parsley and toss to combine. Splash a little lemon juice over everything riht as you serve.

Recipe: Meadow Mushrooms Caramelised Onion Tarts

Ingredients

1. 1 tablespoon olive oil

2. 1 tablespoon butter (unsalted preferable)

3. 1 large onion (red or white), thinly sliced

4. (250g) mushrooms, thinly sliced

5. 1 garlic clove

6. ½ t fresh thyme

7. Salt & black pepper to season

8. ¼ cup white wine (or stock)

9. 2 sheets puff pastry

10. 1 cup Gruyere/Emmental grated

11. 1 egg

12. 1 tablespoon water Chopped parsley to garnish

Instructions

Topping

1. Pre-heat oven to 200 degrees. Line two baking trays with greaseproof paper Heat olive oil in a heavy-bottomed pan, on low heat.

2. Add the onions and cook for 20 minutes, stirring regularly, until caramelized.

3. Add the butter till melted, then add the mushroom until soft and moisture evaporated (10-15 minutes).

4. Add the garlic, thyme, and seasoning and stir for another minute.

5. Deglaze the plan, by adding the wine and stirring thoroughly, cook until absorbed.

To compile:

1. Combine the egg and water well.

2. Cut 16 x 8-10 cm inch circles in the pastry and layout on the baking trays. Prick each with a fork 2-3 times

3. Top with a heaped spoon of the mushroom mixture, leaving a 1cm edge clear. Brush the edges with the egg-wash. Then top with cheese.

4. Bake 15 minutes until golden and sprinkle with chopped parsley to serve.

Recipe: Tasty Mushrooms on Toast

Ingredients

1. 500g Meadow Mushrooms White Buttons or Swiss Browns, sliced

2. 25g butter

3. Salt & pepper

4. 2 cloves garlic, finely chopped

5. 1 Lemon, juiced

6. Parsley, chopped

7. Toast

Instructions

1. Heat a large frying pan. Add garlic & butter and cook briefly.

2. Add the mushrooms. Cook, stirring frequently for 5 mins.

3. Add the lemon juice & parsley. Season with salt & pepper.

4. Serve on thick slices of buttered toast.

Recipe: Mountain Meadow Mushroom Tour and Risotto Recipe

Ingredients

1. 1 small onion, diced

2. 2 tbsp.olive oil

3. 1½ teaspoons salt

4. 8-10 mushrooms, sliced

5. 2 garlic cloves, minced

6. ½ tsp.pepper

7. ¾ cup vermouth or wine

8. 1½ cups Arborio rice

9. 6 cups stock or ½ stock , ½ water

10. ¾ cup Parmesan cheese and extra for topping

11. drizzle of olive oil on top

Instructions

1. Place the stock in a saucepan and keep warm.

2. Heat a heavy bottom pan over medium heat and add the oil.

3. Add the onions and salt and sweat until clear about 6-8 minutes.

4. Add the garlic and cook another 30 seconds.

5. Add the mushrooms, season with pepper, and cook for another 5 minutes, until all the liquid evaporates.

6. Add the arborio rice and toast for 3-4 minutes. Stirring constantly.

7. Add the vermouth and stir until absorbed.

8. Add the warm stock one cup at a time, allowing it to absorb before adding the next.

9. The risotto will take 25-30 minutes. Remove from heat and add the grated cheese.

10. When serving add the olive and top with extra grated cheese.

11. Serve immediately.

Recipe: Veggie Spaghetti Bolognese with Meadow Mushrooms

Ingredients

1. Butter or olive oil

2. 2 onions, chopped

3. 1 tsp

4. 2 sticks celery, finely chopped, optional

5. 2 medium carrots, finely chopped

6. 200g white button Meadow mushrooms, sliced

7. 250g portabello Meadow mushrooms, chopped

8. 1/2 cup chopped parsley

9. 3 garlic cloves, finely chopped

10. 3 tbsp tomato paste

11. 1/2 cup red wine, optional

12. 1 x 40g can chopped tomatoes

13. 1 x 400g can lentils, drained

14. 250mls vegetable or mushroom stock or 250ml water

15. Salt and pepper

16. fresh basil

17. parmesan cheese

Instructions

1. Heat some butter or oil in a heavy-based saucepan, over a medium/low heat. Add the onions and salt and cook, stirring occasionally for 10 minutes. Add the celery and carrots and cook another 20 minutes.

2. Add some more butter or oil to the onions along with the mushrooms, parsley and the garlic and cook for 10 minutes.

3. Add the tomato paste and cook, stirring for 3 minutes. Add the wine if using, bring to the boil, boil for 2 minutes the add the tomatoes, lentils and stock or water.

4. Bring to the boil, reduce to a simmer and cook for 10 minutes. Season with salt and pepper to taste. Serve over pasta with fresh basil and parmesan.

Recipe: Roasted Mushrooms with Ricotta

Ingredients

1. 4 flat mushrooms

2. 1/2 cup ricotta

3. 2 Tbsp coarsely chopped fresh flat-leaf parsley

4. 2 onions, chopped finely

5. 1 clove garlic, crushed

Instructions

1. Preheat oven to 200°C (180°C fan-forced.

2. Place washed mushrooms, stem-side up, on oven tray. Roast, uncovered for about 15 minutes.

3. Meanwhile, combine ricotta, parsley, spring onions and garlic.

4. Fill the top of the mushrooms with ricotta.

5. Cook for a further 3 minutes, so the topping is just melting.

History

The Field Mushroom is a type of mushroom that was first described by a scientist named Carl Linnaeus in 1753. Its scientific name is Agaricus campestris. In the past, this mushroom was called Psalliota campestris, but now it's known as Agaricus campestris. The name campestris comes from the Latin word for a field.

In the USA, this mushroom is sometimes called the Meadow Mushroom. Many mushrooms with gills, including the Field Mushroom, used to be classified under the same genus called Agaricus.

Synonyms and Varieties

• Agaricus alutarius Persoon (1801), Synopsis methodica fungorum, p. 265

• Agaricus campester L., 1753

• Agaricus campestris subsp.* albus Konrad & Maublanc (1927), Icones Selectae Fungorum, 6, pl. 60

• Agaricus edulis Lamarck (1778), Flore française ou description succincte de toutes les plantes qui croissent naturellement en France, Edn 1, 1, p. 117

• Agaricus pellitus Batsch (1783), Elenchus fungorum, p. 55 (nom. illegit.)

• Amanita campestris (Linnaeus) Roussel (1796), Flore du Calvados et des terreins adjacens, Edn 1, p. 34

• Amanita edulis (Lamarck) Lamarck (1783), Encyclopédie méthodique, Botanique, 1, p. 112

• Annularia alutaria (Persoon) Gillet (1878), Les hyménomycètes, ou description de tous les champignons (fungi) qui croissent en France, p. 389 ('alutacea')

• Fungus campestris (Linnaeus) Kuntze (1898), Revisio generum plantarum, 3, p. 479

• Hypophyllum campestre (Linnaeus) Paulet (1808) [1793], Traité des champignons, 2, p. 266, tab. 130, fig. 1-11

• Hypophyllum pseudocampestre Paulet (1808) [1793], Traité des champignons, 2, p. 201, tab. 92, fig. 5-6

• Pluteus campestris (Linnaeus) Fries (1836), Anteckningar öfver de i Sverige växande ätliga Svampar, p. 34

• Pratella campestris (Linnaeus) Gray (1821), A natural arrangement of British plants, 1, p. 626

• Pratella campestris var. alba Gillet (1876), Les hyménomycètes, ou description de tous les champignons (fungi) qui croissent en France, p. 561

• Pratella edulis (Lamarck) Gray (1821), A natural arrangement of British plants, 1, p. 626

• Psalliota campestris (Linnaeus) P. Kummer (1871), Der fürher in die pilzkunde, p. 73

Video

Photo sources:

Photo 1 - Author: Alan Rockefeller (CC BY-SA 4.0)

Photo 2 - Author: Rick Farwell (CC BY-SA 4.0)

Photo 3 - Author: Christine Braaten (CC BY-SA 3.0)

Photo 4 - Author: Leoboudv (CC BY-SA 3.0)