Air Fern - 3 String Sea Urchin

The air fern or Neptune plant is touted as a houseplant that thrives on neglect. It never needs water. It doesn’t even need light. No matter what you do, you can’t kill it because it’s not alive. In fact, it’s not even a real plant.
Air Fern Is an Animal Not a Plant
Although the air fern resembles a plant, it’s actually an animal. Specifically, it’s a colonial animal called a hydrozoan, related to jellyfish and coral. The most common species of hydrozoan used to make air ferns is Sertularia argentea, commonly known as the “sea fir.” Bryozoa or “moss animals” are also used.
Most “air ferns” are picked up by trawlers fishing in the North Sea. The animals are dried so that only their fern-like skeletons remain. Those sold as decorative air ferns are dyed green. If these “plants” are watered, the dye will run. Sometimes Sertularia is left its natural color for use in an aquarium. These versions are called Neptune plants.