Common names: Ricordia, mushrooms, button polyps, hairy mushrooms
Natural origin: Indo-Pacific, Caribbean
Sensitivity (Level 1 to 2): Sensitivity varies some from species to species, but usually tolerant and quite forgiving. When healthy, these corals can rapidly recover from damage and stress.
Feeding: Prey capture ability depends on species and size of the coral polyp mouth. If the tank is regularly fed a healthy variety of food, these corals should have no problem getting what they need.
Lighting (Level 2 to 8): Most can adapt to a wide range of light intensities but sudden changes in lighting can cause bleaching.
Water flow: These corals can thrive in lower flow areas of the tank.
Placement: Though they're not generally aggressive, they can be quite unyielding. A few species can grow quite large (reaching over a foot in diameter) while some species stay relatively small (less than 2 inches across). The larger species include many of the corals commonly referred to as "hairy mushrooms." All species divide as a method of asexual reproduction.
General: Note that these corals will sometimes detach from their rocks and float away. This could be a sign that they are unhealthy or over crowded. However, it could also mean that they are not happy with where they are in the tank and are simply trying to find a more favorable spot. You can try to glue the coral down, but this can be quite difficult if there are grains of sand attached to the foot. It's usually wiser or kinder to just let the coral find the spot it wants. Just make sure that as it ventures around it doesn't get stuck in an obviously bad place (such as in the grate of an overflow or powerhead, or at the base of an incompatible coral).  These corals can be fragmented by cutting into sections.