AbstractLight-capture efficiency of the microstructure of protonemal colonies ofScoplophila cataractae, was investigated. Colonies situated at shaded locations and not facing the direction of canopy openings showed a wave-like structure, consisting of mostly parallel laminae extending 2–12 mm from the vertical surface of the substrate. Light irradiance was estimated to be 2.0–2.5 times higher on the upper surfaces of the laminae than on the stone base on which the moss was growing. The wave-like structure is a result of the growth of fibrous protonemal cells perpendicular to the main direction of the incident light. A correlation was found between the height of a lamina and its distance from the adjacent lamina, indicating self-thinning processes during formation of the lamina structure.