Characters: Colonies are submassive, encrusting or form contorted anastomosing branches, and are commonly over 5 metres across. Corallites are separated into groups by ridges which characteristically converge towards each other forming flame-shaped patterns.
Colour: Pale cream, yellow or dark bluish-brown, often with pale branch tips. Sometimes brightly coloured in shallow water.
Similar Species: Porites rus can be confused with Montipora underwater. Closest to P. monticulosa. See also P. deformis, P. cumulatus and P. ornata, all of which have small corallites.
Habitat: Shallow reef environments.
Abundance: Common and may be a dominant species in a wide range of habitats.
Taxonomic Note: A species complex which is likely to be divisible into several cryptic species. The species irregularis has been used with three related genera, Porites, Napopora and Synaraea. Porites irregularis Verrill (1864) is not recognisable from the original description. The Porites irregularis of Vaughan (1907), Nemenzo (1955) and Maragos (1977) is this species. Napopora irregularis Quelch (1884) (illustrated by Bosserelle, Berteaux-Lecellier, Chancerelle et al., 2014) is currently under review but is likely to be accepted as a valid species.
Taxonomic References: Veron and Pichon (1982);
Identification Guides: Randall and Myers (1983); Veron (1986a); Sheppard and Sheppard (1991); Nishihira and Veron (1995); Pillay, Terashima, Venkatasami et al. (2002); Fenner (2005); Pichon, Benzoni, Chaineau et al. (2010); Turak and DeVantier (2011b);
