Nothing edible to share today, but I wanted to make a post about a mushroom that gets asked about all the time on Reddit and Instagram.
The question "What is this yellow mushroom growing in my house plant / planter / garden?" is one I see every day, and today I'm here to answer it.
95% of the time you are looking at Leucocoprinus birnbaumii, sometimes called the yellow parasol mushroom, the painted dapperling, or the flowerpot parasol. Yes, it's so common in flower pots that it actually has that in the common name. The other 5% of the time you might be looking at the closely related Leucocoprinus straminellus, which is generally a paler shade of yellow, or Leucocoprinus flavescensm which generally has a brown area in the center of the cap.
Both L. birnbaumii and straminellus are tropical or subtropical mushrooms, so finding them in nature in the continental US, Canada or northern Mexico is extremely rare, but extremely common in potting and gardening soil. This is most likely due to the common usage of tropical materials, like orchid bark, in purchased soils. These organic materials may be contaminated with L. birnbaumii spores which then grow mushrooms when conditions are warm enough.
For most North Americans this means late spring, summer or early fall, but if you have a greenhouse, the yellow parasol might pop up anytime.
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| Bell shaped when young |
Yellow parasol mushroom description
A bright, dainty mushroom that's yellow all over, cap, stalk and gills. L. birnbaumii is bright yellow and L. straminellus is pale or whitish yellow.
The cap shape starts out as a bell or cone or occasionally a marshmallow shape, then expands to an umbrella, and then the classic, nearly flat, parasol shape. When in the umbrella stage, the edges of the cap generally have fine striations (lines) and the cap will have small fibrous or warty raised areas all over, and the middle area will usually be raised -- this is called an umbo. At maturity, the cap will be anywhere from 1.5" to 3.5" in diameter.
The stems are narrow near the cap and thicker at the base, even somewhat bulbous as they enter the soil. The stems will usually feature a ring, sometimes a double ring. The mushroom should be 2" to 3.5" high at maturity, but might be as tall as 4.5" in rarer cases.
Is the yellow parasol mushroom poisonous or edible?
Reports are conflicting on whether L. birnbaumii is toxic, but it definitely should NOT be eaten. Many Leucocoprinus species are severe sickeners, and symptoms can be dangerous.
