During this period exotic plants from the East Indies and India were being cultivated in greenhouses and stove-heated hothouses at Wormleybury making it likely that this is where the mushrooms were found.

[14][15] In 1839 the Czech mycologist August Corda described the same species from Prague where it was found growing in a greenhouse in between pineapple plants by a garden inspector named Birnbaum and so he called it Agaricus Birnbaumii.

[22] As this species is adept at spreading via potting soil and with transplanted plants it is possible that descendants of the mushrooms found by Mr. Birnbaum continue to grow amongst them.

Cap: 2–7.5 cm wide in maturity, starting bulbous to cylindrical before expanding to hemispherical or conical and flattening or sometimes appearing umbonate with age.

The scales are darker yellow or brownish with age and more densely concentrated towards the centre disc where they often form a patch whilst at the edges they are sparser.

One feature of Leucocoprinus birnbaumii which isn't often described but is frequently visible are the sclerotia amongst the mycelium on the surface of the soil, which is an unusual trait amongst members of the Agaricales.

Hennings describes the sclerotia as small (barely 1mm), light yellow and felt-like, with them covering entire areas of plant pots and beds.

Hennings concludes that the species was likely introduced from South America citing specimens of sclerotia in the Berlin herbarium that were collected from Guadeloupe.

[32] Hennings compares them to Sclerotium mycetospora, which was described in 1822 by Elias Magnus Fries as being like mustard seeds which were white, furry and spread gregariously amongst the bark in a hothouse where they appeared to favour the light.

[33] Typically sclerotia are most often discussed in the context of truffles or in the challenges faced by attempts at morel cultivation[34] so are usually associated with large, hardened masses growing under the ground.

The sclerotia in L. birnbaumii however are tiny (500-820 μm) hard, elliptical masses on top of the soil amongst the fibrous mycelium which have been described as whitish-beige or pale yellowish white.

In a 1907 study the American mycologist Andrew Price Morgan documented Lepiota lutea growing in greenhouses in Columbus, Ohio.

[43] In 2019 a study documented L. birnbaumii growing from the stump of a dead lemon tree in an orchard near Damietta, Egypt during the Autumn.

[51] A 2015 study succeeded in isolating a number of fatty acids from Leucocoprinus birnbaumii which showed moderate but selective anti-microbial effects.

Despite this tropical species likely being unable to survive in these countries in the wild due to the cold temperatures it continues to spread via human activity.

The heat and humidity of greenhouses or indoor plant pots evidently creates a habitat in which this species can thrive with garden centres and nurseries serving as hubs to distribute L. birnbaumii all over Europe.

[40] However, when L. birnbaumii mushrooms suddenly appear in a plant pot which had shown no previous signs of them it doesn't mean the fungus has only just been introduced.

Due to the length of time the mycelium requires to grow, it is more likely that the fungus was always present in the soil from the moment the plant (or compost used) was acquired and that the conditions for it to fruit have only recently been met.

The presence of this fungus in the soil may serve to improve the quality of it as it can help to break down organic matter and provide nutrients that the plants require.