Distribution: Uncommon in the Solitary Islands Marine Park. The genus is found throughout the Indian and western Pacific Oceans, from Madagascar and the Red Sea, to the Line and Tuamotu Islands, north to Japan, south to Lord Howe Island. In Australia at least four species found from around Perth in Western Australia, across the north of the continent, south through the Great Barrier Reef to southern Queensland and including Middleton and Elizabeth Reefs and Lord Howe Island.

Ecological Notes: Found in a variety of sheltered areas such as lagoons and reef flats protected from strong wave action.

Additional Notes: The genus has a variety of growth forms – massive, encrusting or arborescent (elongate tree like branches). Polyps are usually only extended at night except for H. excesa or H. pilosa. Colours may be cream, dull green brown or grey. 

References: Veron, J.E.N., Corals of Australia and the Indo-Pacific. Angus and Robertson Publishers, 1986. Pp. 428-433.