Endemic

Name honors L. Earl Bishop (1943-1991), who earned his doctorate at the University of Hawai'i studying Adenophorus. His later work expanded the knowledge of the family Grammitidaceae.

Uncommon, with characteristics intermediate between two parent species. Rhizomes and rhizome scales same as in parent species. Fronds erect or arching, 3-9 X 0.3-1 cm. Stipes round at very base, becoming winged and merging with blades. Blades long-elliptic, widest in middle, usually incised 2/3 or less to midrib, lobes obliquely deltoid to oblong or occasionally crenate, tips caudate, often unlobed when larger, hairs few and scattered over the abaxial surface, often with glandular tips. Veins 1-to 3-forked, rarely somewhat pinnate in largest lobes. Sori mostly solitary on each lobe, glandular paraphyses present.

An uncommon hybrid between Adenophorus oahuensis and A. pinnatifidus that is found in the Ko'olau Range of O'ahu anywhere both parental species grow together. Usually A. oahuensis grows higher on a tree trunk, A. pinnatifidus grows lower, and the hybrid between them. The spores of this hybrid appear normal and may be partially fer-tile. Some collections suggest a backcross with A. oahuensis.

Adenophorus oahuensis x A. pinnatifidus may be recognized by its intermediate characters and it proximity to the parental species.

There are plants with characteristics intermediate between A. oahuensis and A. haalilioanus, and between A. haalilioanus and A. pinnatifidus that may represent either intra-specific variation or hybridization. Further study is needed.

Reference: Bishop (1974).