This is a fern from Africa south of the Equator. It grows in deep shade on the forest floor in moist tropical and sub-tropical forests. The distinctive feature that gives the fern its name are the snail-like gemmae produced along the midrib on the upper surface of the frond (the lower surface bears the usual spore-producing sori and sporangia). The gemmae are produced asexually, so they have the same genetic make-up as the parent. Gemmae or similar asexual propagules are produced on plants in diverse parts of the plant kingdom. For example, gemmae occur in liverworts and clubmosses and structures called bulbils are produced on the stems of lily species.