Our Missouri Botanical Garden must have thousands of species of plants. Being a child of the concrete jungle, I usually have no idea what's what. We use a phone app called PlantSnap, which can identify most of them from taking a photo and comparing it to an image database. This is the bud of a Greek peony, which the app says is endangered. It's well cared for here.
We have the return of a big annual event at the garden this weekend, the Chinese cultural festival. It's a photo feast but the forecast is for on and off thunderstorms all day. If we can go, you will see it here.