The areolas appear separated, but are (or were) connected by an underlying "prothallus" or "hypothallus". The prothallus develops from a germinating spore. A light coloured prothallus may be visible in well-developed specimens. The prothallus development is of the "Adiantum" type. The prothallus is red to whitish in the inner part, red the in outer part. The prothallus is either absent or vestigial, with areoles sometimes being contiguous and sometimes scattered.