Leucocoprinus birnbaumi (little viberent yellow mushroom) 

 Leucocoprinus birnbaumii is a species of gilled mushroom in the family Agaricaceae. It is common in the tropics and subtropics. However, in temperate regions, it frequently occurs in greenhouses and flowerpots, hence its common names of flowerpot parasol and plantpot dapperling

Leucocoprinus birnbaumii is a toxic mushroom. If eaten it can cause stomach upset as its toxic mechanism is a gastrointestinal irritant

The yellow color of the mushrooms is from alkaloids known as birnbaumins. Birnbaumin B is the major compound and has a formula C16H20N6O5 whilst birnbaumin A has one less oxygen molecule