Species unknown. Sulphur-yellow colour, cap approx 10-15cm across when open, body approx 2-3 cm when closed. Striations on top surface of open cap, gills on lower surface. Found in planter, growing around pittosporum
Leucocoprinus birnbaumii, sometimes called Flowerpot Parasol or Yellow House Plant Mushroom because this is where most people notice them. They do grow in the bush as well. Some great photos as you've captured the contrast between the immature and mature ones. It's not on the species list as yet.