The fronds of R. adiantiformis contain round sori (reproductive clusters) on the underside of the pinnae (leaflets) unlike many other ferns which have separate specialized reproductive fronds.
An example occurrence in central Westland podocarp/broadleaf forests includes flora associates such as Cyathea smithii and Dicksonia squarrosa, Rumohra adiantiformis, Ascarina lucida, Pseudowintera colorata and Blechnum discolor.