Agaricus praeclaresquamosus is the most common large mushroom in my area with massive fruitings, of many pounds each, all over the place. It's also toxic to most people and smells bad, like phenol or band-aids. It smells really terrible while being cooked. This year, amid enormous rainfall, these mushrooms which are usually nearly pristine white with a little grey in the cap centres, are seemingly imitating shaggy parasols,one of my favourite edibles. Have a look at these photos I took locally in the last few weeks. Notice the gills that are at first pink then turn chocolate brown when sporulating. Shaggy parasols Chlorophyllum rhacodes have off-white gills and milk white spores. THey stain orangey red when crushed or cut. Older specimens less so. There is another similar toxic to rhacodes the green-spored Chlorophyllum molybdites, that doesn't grow in my area. If anyone knows if they stain as above, please let me know. SOme preaclaresquamosus also bear similarity to prince mushrooms, Agaricus augustus, which are more golden and smell of almonds. All our species grow in the same habitats, sometimes interspersed. I have almost mistaken them many times. It pays to be VERY careful.