Characters: Colonies have both horizontal and upright irregularly folded fronds. Valleys are parallel to frond margins except towards the base of fronds where they become irregular. Collines are wavy. Columellae are wall-like and clearly fused with septo-costae. Colour: Brown. Similar species: May be similar to tiered forms of Pachyseris speciosa except that fronds are usually more vertical; columellae are similar to those of P. rugosa although less conspicuous. Habitat: Semi-protected reefs. Abundance: Rare.