Family: Ceratophyllaceae (HORNWORT).
Generic common name: HORNWORT, COONTAIL.
Not photographed yet.
If you see this in or near the SMM floristic region we'd like to know
Note: the classification of this family as presented in TJM2 is now very different from the classic taxonomic classification system proposed decades ago by Cronquist. We still use the Cronquist system as it seems more suited to our desire to sort the flowers by visual similarity.