Characters: Colonies are digitate, corymbose or prostrate, with curved branches which only slightly taper. Colonies may be over one metre across. Axial corallites are dome-shaped and more than twice the size of radial corallites. Radial corallites are of two sizes, thick walled, tubular, and only slightly increase in size down branches. Incipient axial corallites and branchlets develop towards the base of branches.
Colour: Usually purple, blue (which may photograph pink) or cream.
Habitat: Upper reef slopes.
Abundance: Usually uncommon.
Taxonomic Note: Well-defined species in the field but not in collections where it may be confused with A. wallaceae and to a lesser extent A. torresiana both of which Wallace, Done and Muir (2012) synonymised with A. samoensis. It may be noted that the holotype is a stout, thickened corallum and sits at one end of the range of its morphological variability. A. wallaceae is more similar to this specimen than it is to the neat, digitate to corymbose form of A. samoensis which is more typical of the species. The three species of the complex require further taxonomic study to clarify their boundaries.