Lot's of ideas. First I thought it was a fern because I've been researching them and now everything looks like a fern. Then I thought yarrow but since the leaves and flowers are wrong that seems unlikely, both are plants however so pretty close for me. Then I figured out the answer...that I suck at plant ids.

This does seem like a tough one. I've gone through a couple field guides so far and nothing close...

Since this seems to be stumping readers here...there is a forum on GWeb just for plant id. Readers there seem very good at plant id no matter the location.

Artichoke blooming ???????

Maybe Cymopterus multinervatus?

Great guess, but I now suspect this is the closely related Cymopterus purpurescens.

Thank you both. I can sleep tonight. These plant id games drive me nuts. One day someone is going to cut a flower off one plant, stick it on another, take a picture, and that'll be the end of waterbug.