Ragionula rosacea is an erect bryozoan. Colonies are composed of a short stem and a number of rigid, broadly palmate branches with an equal horizontal spread. The branches are made up of two layers of zooids arranged back-to-back. The colony may reach up to 20 mm high and is white or delicate rose in colour. Autozooids are oval to hexagonal and strongly convex, with two short oral spines present on young zooids.
Ragionula rosacea is an arctic-boreal species with a circumpolar distribution. It reaches its southern limit in the north-east Atlantic off Shetland and northern Scotland.
The species is able to colonise stones and shells. It attaches to the substrate by an encrusting sheet of autozooids and can be found in offshore subtidal waters.