Ruth writes:

A family friend of mine, Sandi Hewlett, submitted this photo from a walking tour that she took in the Sierra de Aracena of southwestern Spain. Thanks so much Sandi!

Apparently, this graceful water weed, commonly known as the white water-crowfoot, is found all over North America. I've never seen it! Ranunculus aquatilus also grows in still water bodies of Europe, Africa and Asia (it was also previously featured on BPotD here: Ranunculus aquatilis).

If you look closely, you can see that there are two leaf forms present on this plant. The submersed leaves are feather-like with many leaflets (>20), whereas the leaves that float on the surface are broad and flat with a scalloped edge. Some sources hint that the surface leaves prop up the flowers, as they are produced at roughly the same time. The flowers appear around May, which is when this photo was taken.

Like similar flowering water plants (e.g., Nymphaceae), beetles are attracted to the flowers and may be an important pollinator. Other insect interactions include the flowers supplying shelter for water spiders and larvae of dragonflies & damselflies.

The fruit is a one-seeded indehiscent achene, a trait shared by many members of the Ranunculaceae. The achene is eaten by waterfowl.