The plums you show in the first picture are elongated ovals and look to me like what I know as Italian Prune PLums.
Is the flesh yellow and wonderfully sweet?
On the farm where I grew up there were two huge trees with those plums, planted who knows when by the Shakers when they owned the property and that takes us back to the mid-1800's.
I've been having a discussion with a local lady who says she won't eat ANY plum that has yellow flesh, only those that have red flesh. I told her that plums were domesticated in China, which they were, and then moved West and that the sugar level (Brix) content of yellow fleshed plums was higher than red fleshed plums.
Plum cookies? Never heard of using them for cookies, so why not cakes and more?
Just noting that my mother was a mushroom picker, learned from her relatives, and my brother and I used to go with her to find them. Not in the woods, but in abandoned pasture where cows used to roam.
I love mushrooms and in the Hudson Valley south of where we lived there were several commercial places where they grew the typical white button ones in caves and my father would bring home from market the oval boxes they were packed in.
And when I moved where I am today there was a wonderful place where they raised all kinds of mushrooms for sale, but the place burned down, so no more mushrooms from them.
The closest access I have to local mushrooms now is that they grow in the track of a sliding door, not on the track itself, but in between the screen and the glass door.
I don't harvest them, I just look at them.
Carolyn