Saltwater
Halimeda opuntia
Halimedaceae
Halimedaceae
Seen in the wild in American Samoa, Antigua & Barbuda, Australia, Bahamas, Barbados, Belize, Brazil, Cayman Islands, and 56 more countries.
Halimeda opuntia, sometimes known as the watercress alga, is a species of calcareous green seaweed in the order Bryopsidales. It is native to reefs in the Indo-Pacific region, the Atlantic Ocean and the Mediterranean Sea.