I haven't seen water hyacinths do anything but float around (and be eaten by koi) so I was surprised to see a bloom on this one. And stupidly I thought "Well, that doesn't look like a lily!" forgetting that they are hyacinths, not lotus-lilies. And they really do look like hyacinths:
The other thing in the pond is the hard-to-read thermometer. Right now since I put in the plants, and the hay bale in the filter, the string algae has disappeared. I don't miss it.