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

Thanks! This is very helpful.
I was lucky enough to have portobellos grow in another bed I started.
I’m not having any luck with growing Oysters so far.
I’m waiting to see if the Almond Agaricus take hold and fruit.

They look exactly like my almond agaricus I planted in a pot last year and tried yesterday.

I’d get a spore print, should be chocolate brown. My almond agaricus pot fruited for the first time the other day and I tried them yesterday. They were delicious! Better than any portobello I have ever had.

Almond agaricus should be non-staining flesh when cut, a pleasant odor when crushed and while cooked. My friend uses the smell of the cooking agaricus mushroom to tell if it’s edible, with a chemical odor being a sign of toxicity, but I prefer to identify to species first.

This key helped me: https://mushroomexpert.com/agaricus.html

Afraid to say, I'm mightily suspicious of wild mushrooms.  Those pictured look very like one that grows in our paddocks. Two varieties - One is OK - the other can be toxic to some people - this latter stains yellow when a finger nail is run over the cap, and is generally to be avoided.

Thanks!