Macrolepiota procera

Description

Macrolepiota procera is a spectacularly large, distinctive, pale brownish mushroom that has a scaly cap, white gills, and a pale brownish stem with a snakeskin pattern and ring. It grows solitary, scattered, or clustered on the soil in open grassy places and in mixed woods.

In North America, we appear to have several "parasol mushrooms" going under the name of the Eurasian species Macrolepiota procera. Many, if not all, of these species, are undescribed and unnamed.

Common names: Parasol Mushroom.

Mushroom Identification

1. Fruit body

   Parasols have a broad, scaly, brownish cap with a bulbous base, tall, scaly, brownish stem with a movable ring.

2. Cap (pileus)

   Ovate (egg-shaped) becoming bell-shaped then nearly flat. 3-10 inches wide with attached scales in a regular pattern and a central knob that is brown at first but cracks with age revealing the white flesh. A mature cap may smell of maple syrup.

3. Gills (lamellae)

   Broad, rough-edged, white, close, free gills.

4. Stem (stipe)

   3-12 or more inches tall. 3/8-5/8 inches thick. Enlarged to bulbous at the base with brown scales that have a pattern somewhat resembling herringbone. The partial veil becomes a ring that slides up and down the stem.

5. Flesh

   White and moderately thick and non-bruising.

6. Spores

   White spore print.

7. When and where to find them

   The Parasol Mushroom may be found on lawns, trail or woods edges, and in the woods. They may or may not be near trees although they can have a preference for certain trees. Oak or white pine or other conifers are good places to look but they can be in any mixed woods. Large specimens are often found on lawns sometimes in large numbers and may be as much as a foot tall.

Cultivation Tips

Parasol mushrooms are a bit challenging to grow at home. However, it’s possible to grow them using a mixture of compost and straw layer substrate and a similar method to growing horsetail mushrooms.

The mushroom substrate has to mature for several weeks before it can be inoculated and placed outdoors. Keep in mind that this mushroom likes to grow in relatively low temperatures between 54 to 68 F (12 to 20C). So start the cultivation process in a cool and dark place first such as a basement.

Here is the basic process for growing Parasol mushrooms:

1. Spread a generous 2 to 3 inch (5 to 7.5 cm) layer of compost in a large compact container and top with a wheat straw substrate. Make sure to soak the substrate in hot water before layering to ensure that there are no contaminants that could ruin the growth of the mushroom.

2. Make several small injections of Parasol mushroom mycelium in the substrate and compost mixture. You may find Parasol mushroom mycelium in several offline and online nurseries and specialist mushroom stores.

3. Top your bed with a plastic sheet. Make several small incisions with a knife, so that moisture can pass through to the substrate.

4. Spray the substrate through the holes of the sheet with water around once a day.

5. The mushrooms will start to colonize and fruit in around 5 weeks. But it may take up to 2 months for them to fully grow to a standard size and be ready for harvesting.

Macrolepiota procera Look-Alikes

1. Chlorophyllum rhacodes

   Smaller but similar in appearance is the common shaggy parasol. Its edibility is suspect as it causes mild sickness in some people, especially when eaten raw. One must learn to distinguish the two as their geographical ranges overlap.

   Differences from the parasol mushroom include its smaller dimensions, pungent (fruity) and reddening flesh when cut, lack of patterns on its stipe, and very shaggy cap surface.

2. Macrolepiota mastoidea

   European species is yet another very large edible mushroom. Its dimensions are generally smaller than that of M. procera and the markings on its stipe less obvious. It is also much rarer.

   Species of Agaricus have brown spores and the gills of mature specimens are never white.

1. Chlorophyllum molybdites

   Species that cause the largest number of annual mushroom poisonings in North America due to its close similarity. Faintly green gills and a pale green spore print give it away. Furthermore, this mushroom lacks the aforementioned snakeskin pattern that is generally present on the parasol mushroom. Its range is reportedly expanding into Europe.

2. Leucocoprinus brunnea

   Found in North America. Slowly turns brown when sliced.

   White and immature species of Amanita are also a potential hazard. To be sure, one must only pick parasol mushrooms past their button stage. A general rule of thumb with the parasol mushroom as compared to amanita species is that the parasol mushroom has darker flakes on a lighter surface, whereas amanita species have the opposite, lighter flakes (if there are any) on a darker surface, such as the Panther cap.

3. Cystoderma amianthinum

   Also, know as Saffron Parasol is very much smaller, and not often eaten.

4. Lepiota brunneoincarnata

   Is a lepiota species known to have caused mortal intoxications in Spain. It is much smaller than Macrolepiota procera.

Cooking Notes

If you gather these large meaty mushrooms to eat, be aware that the somewhat similar Shaggy Parasol, Chlorophyllum rhacodes, can cause tummy upsets. The Shaggy Parasol has flesh that turns red when it is cut, and its stem lacks the snakeskin-like patterning.

Avoid small specimens. It is possible to find examples of Lepiota procera with caps smaller than 10cm across when fully expanded; however, they make only modest meals and, more importantly, you could by mistake end up collecting some of the small poisonous Lepiota species. One simple way of minimising such risks is to shun any specimens with caps smaller than 10cm across when fully expanded; but do also check carefully the other identifying characters of this delicious mushroom.

All fungi deteriorate in flavor and texture as the fruit bodies become old. (They may even become flyblown and maggoty.) So main recommendation to gathering Parasols at the 'large drumstick' or 'partly expanded umbrella' stages of development.

Macrolepiota procera mushrooms are popularly sauteed in melted butter.

In central and eastern European countries this mushroom is usually prepared similarly to a cutlet. It is usually run through egg and breadcrumbs and then fried in a pan with some oil or butter.

A savory Slovak recipe is to bake caps stuffed with ground pork, oregano, and garlic.

Italians and Austrians also serve the young, still spherical caps stuffed with seasoned minced beef, baked in the same manner as stuffed peppers.

History

Originally described in 1772 by the Italian naturalist Giovanni Antonio Scopoli - his name is sometimes Latinised to Joannes Antonius Scopoli - who called it Agaricus procerus. The Parasol Mushroom was transferred to its present genus by the famous German-born mycologist Rolf Singer in a 1948 publication.

Synonyms of Macrolepiota procera var. procera include Agaricus procerus Scop., and Lepiota procera (Scop.) Gray.

Several former members of the Macrolepiota genus are now sited in the genus Chlorophyllum, which contains a number of large parosal-like fungi now known to be toxic to many people - for example, Chlorophyllum rhacodes, the Shaggy Parasol.

Macrolepiota procera is the type species of the genus Macrolepiota.

Two varieties of this species are formally recognised. the nominate form, var. procera. Macrolepiota procera var. pseudo-olivascens Bellù & Lanzoni, as defined in 1987 and is generally found under conifers; it differs visibly in developing olive stains on the cap surface.

The specific epithet procera means tall, an adjective wholly appropriate to these stately mushrooms.

Photo sources:

Photo 1 - Author: Guillaume Hoffmann (CC BY-SA 4.0)

Photo 2 - Author: This Photo was taken by Böhringer Friedrich (CC BY-SA 3.0)

Photo 3 - Author: Chrumps (CC BY-SA 4.0)

Photo 4 - Author: Gabriel Mayrhofer (Public Domain)

Photo 5 - Author: Calum McLennan (CC BY-SA 4.0)