This pair were Common Green Darners, familiar big green (or green and blue, in the case of the male) dragonflies. They stayed hooked up (the male's claspers gripping the female firmly by the head) for over a half hour, while she laid eggs repeatedly in different parts of the lily pond.
But then I saw something small--wasp-sized--with brilliant orange wings--poised on the edge of an upturned water lily leaf, its striped abdomen sticking up in the air...and realized I was looking at a very small dragonfly I'd never seen before. It was a male Eastern Amberwing.