Info from AIMS:
Characters: Colonies are arborescent with cylindrical branches but may be corymbose, with horizontally fused basal branches which have upturned ends. They may form stands more than 5 metres across. Branches are smaller than those of the large staghorn Acropora species. Radial corallites are of mixed sizes, with projecting lower lips.
Similar Species: May superficially resemble Acropora formosa and A. yongei, but radial corallites are distinctive. Acropora aspera has similar radial corallites but these are much larger and more scale-like. See also A. loisetteae.