Portobellos or …?

Anyone have an inkling of what these shrooms might be? They did come up about 5 feet from where I inoculated an area with portobello spores last year. The ones with pink underside has a flesh layer on top of the gills that comes off. The other ones with the dark gills and the tops that look like portobellos … might be them but they are a bit thin not the typical fat flesh of a portobello.

Megan, those mushrooms definitely look like Agaricus- with gills that turn from pink to chocolate brown, but they are probably not Portobellos (Agaricus bisporus). Agaricus is an extremely complex genus, comprising over 200 species in North America. In the words of David Arora: "Agaricus species are perplexingly polymorphic." There are several characteristics to separate the different species, including staining reactions, odor and veil characteristics.  Some species are delicious and some are toxic. In my experience, I've found that portobellos (which are the same species as white button mushrooms) are not easy to grow from spores and are extremely rare in the wild. Here is a key to this perplexing group of mushrooms from Michael Kuo:

https://www.mushroomexpert.com/agaricus.html