Characters: Colonies are columnar or consist of thick irregular upright branches. Branches divide at infrequent intervals and sometimes fuse. One or more poorly defined axial corallites are formed at branch ends. Incipient axial corallites form along ridges. Radial corallites are tubular and irregular in length, giving branch surfaces a rough texture. The coenosteum is composed of fine spinules with elaborated tips.
Colour: Pale to dark brown.
Similar Species: Isopora palifera, which does not have fused branches and has a smooth surface without irregularly exsert corallites. See also I. brueggemanni, which does not form thick branches and has well defined axial corallites.
Habitat: Shallow reef environments and rocky foreshores.
Taxonomic Note: Placed in probable synonymy with Isopora palifera by Wallace, Done and Muir (2012). However these species have been clearly differentiated in both field and skeletal studies.