Limey Petticoat Padina gymnospora
Padina is the only genus of brown seaweeds to have calcified fronds, hence this species’ common name of limey petticoat. The reflective chalk shows as bright white concentric bands on the upper surface of the fan-shaped fronds. The fronds are only 4–9 cells thick and curled inward. Older fronds may become split into wedge-shaped sections. This species is widespread in tropical seas, often growing in masses on shallow subtidal rocks, and on old coral and shells.