Pyrophyllon subtumens is an obligate red algal epiphyte of Durvillaea southern bull-kelp, and is endemic to New Zealand.
[1][2] The species belongs to a monotypic genus, which is sister to Childophyllon - a genus containing another red algal epiphyte of other seaweeds in New Zealand.
The species was previously recognised as Porphyra subtumens before being reclassified.
[2] The species can be found growing on all mainland New Zealand species of Durvillaea.