The only species is Phyllodiscus semoni, commonly known as the night anemone, which is native to shallow seas in the central Indo-West Pacific, such as Indonesia, the Philippines and southern Japan.

The lower portion of the column is smooth and the middle section has a radially arranged series of pseudo-tentacles, thick, stalked and branched outgrowths which show great variety in their appearance between different individuals.

The aggregations include a range of different-sized individuals and are likely to be clones formed by asexual reproduction, possibly by fragmentation when the sea anemone moves across the substrate.

[5] This sea anemone is venomous and its stings can cause painful injuries to humans, and on rare occasions can result in acute kidney damage.

Several haemolytic toxins have been isolated from Phyllodiscus semoni and it is the first sea anemone whose venom has been shown to damage the kidneys and cause acute renal failure.