Plants small to medium-sized, epiphytic, occasionally epigeous. Rhizomes short to long-creeping, decumbent to erect, roots sometimes proliferous. Fronds usually small (sometimes long in Adenophorus periens). Stipes round, dark brown to black. Blades simple to 3-pinnate, deltate to long-linear, very glandular to glands absent. An endemic genus of two subgenera with nine species. Subgenus Oligadenus is segregated within the genus Adenophorus because of its much less-dissected fronds, lesser to absent glandularity, difference in the character of the glands, absence of creeping rhizomes, and presence of root proliferations, Species in subgenus Adenophorus form clones by rhizome growth and branching, whereas those in subgenus Oligadenus form clones by root buds. There are hybrids between species in each subgenus, but none between the subgenera. DNA and isozyme studies suggest a close relationship between Adenophorus and Grammitis tenella and further study is needed to clarify these relationships.

KEY TO THE SUBGENERA OF ADENOPHORUS

1. Fronds 1-pinnate-pinnatifid to 3-pinnate; glands abundant, large, ovoid, resting on a thick basal cell; rhizomes short-to long-creeping; asexual. reproduction by branching rhizomes ............... 1. subgenus Adenophorus

1. Fronds simple to deeply lobed; glands absent to sparse, small, spherical, at tips of long, thin hairs; rhizomes resemble small caudices; asexual reproduction by root proliferations ................... 2. subgenus Oligadenus