I have several Prunus serotina, including one large tree that is approx. 50 years old. The big tree makes zillions of seedlings in my back gardens so it a likely culprit for mkaing your seedling. It is a wonderful tree for wildlife but grows fairly large with a somewhat rangey habit. The bark becomes dark and scraggy looking in old age. I would plant in a naturalized area. #4 looks like my Aster cordifolius (aka Symphyotrichum cordifolium). I've got lots of it - also a prolific self-sower. What a gorgeous haze of tiny lavender flowers in early fall, esp in mass.

I still think it was you but don't remember that much if kids were there. Wife black straight hair? Last Saturday at the Devonian gardens we talked about prunus Siberica and thought it to be a rather minor deviation of prunus Manchirica. Even though Siberica is likely to carry over the pink I still have one reserved thought that Robert Purvis knows of about Siberica. That it is an incredibly slow grower and is dwarf. Robert used to live in Alaska and in Idaho still does nothing but apricot in one of his collections in Washington. Gabe Botar was at the gardens who is another person knowing a great deal about apricot. He had scions of a prolific dwarf apricot with small good tasting fruits that he produced from crossed parents. Good stuff because slow growing and dwarf is always great for extreme cold or unprotected sites. For example flowering under the snow would delay bloom and escape the damaging spring frosts. If Clair Lammers (formerly from Edmonton) from Alaska ever grew Gabes apricot he would at least had fruits from this where all other his Manchurica experiments failed. My grandfather may have been around as a retired forester at the time those were planted and lived very close by. Only a remote possibility exists. I came across the trees a few years ago because I wanted to visit my childhood memories of the wading pool that still there in that place and not that anybody told me. Who ever planted them it seems very possible it was done from self pollinated Goldcot seeds similar the way you collected from the pink tree the seeds for another generation.

Buckeye trees seems to be gaining in popularity lately. Made a road trip from Cleveland to Detroit yesterday and noticed specimens at several rest stops along the way. There are also a bunch of municipalities around here planting them as street or park trees of late. I always thought they were susceptible to fungus and burning in dry, sunny conditions, and thus kind of a risky tree to plant in the open. Maybe there are improved varieties available now. Great if so, because the trees have terrific foliage and flowers when thriving (as seen in the pictures above).

It is sweet allysum, Lobularia maritima, This is an annual so generally not considered to be a groundcover. However it reseeds rather freely so once planted and left to flower, it will typically come back with such regularity that it almost appears to be a perennial groundcover.