The following taxon apparently lies within the circumscription of Colpomenia sinuosa but has not yet been transferred or reduced to synonymy:
Asperococcus sinuosus (Mertens ex Roth) Bory de Saint-Vincent var.? firmior Sonder, 1846 [1846–1848]: 156 (type locality: Western Australia).
INDIAN OCEAN DISTRIBUTION: Australia.