Characters: Colonies consist of whorls of narrow, unifacial, bifurcating fronds. Valleys are generally parallel to frond margins but are short and irregular. Centres are short, especially towards branch bases, where many are not elongated at all. There is almost no development of columellae.
Colour: Pale brown.
Similar Species: Pachyseris foliosa has a similar growth form but valleys are shallower and longer and there is no tendency for centres to be irregularly distributed along valleys. Pachyseris rugosa may form fronds and valleys of similar shape, but fronds are bifacial and the columella wall is conspicuous.
Habitat: Shallow reef environments.
Taxonomic References: Veron (2000a);