Palythoa grandiflora is a zoantharian (family Sphenopidae) found in shallow tropical Pacific reef environments, forming colonial encrusting mats with large, distinctive polyps that incorporate foreign particles into the coenenchyme. Like other Palythoa species, it is a potential producer of palytoxin and related bioactive compounds that are of significant toxicological and pharmacological interest. The species contributes to the structural complexity and competitive dynamics of shallow tropical reef communities. Genomic data have been generated for this species and are available in public databases, enabling comparative studies of cnidarian evolution and ecology.