Endemic

Name honors Miss E. S. Boyd, student of Hawaiian ferns and collector of the type spec1men; Eaton named the species for her in 1897.

Plants small to medium-sized. Rhizomes decumbent to erect, less than 1 cm diam., Wlth larger, tangled mass of roots forming a holdfast. Fronds stiffly upright, clustered at apex, usually 10-30 cm long. Stipes straw-colored. about 1/3 frond length. Blades 1-pinnate. Pinnae lanceolate, 2-3.5 cm long, usually with a small acroscopic, basal auricle, margins crenulate, tips obtuse. Veins anas-tomosing irregularly to form areoles, occa-sionally free. Indusia broader than sori.

Rare and occurring in only a few popu-lations on rocks and ledges of periodically inundated stream margins at about 550 m in the Ko'olau Range of O'ahu and at 1,315-1,350 m in Kipahulu and Waiho'i Valleys of East Maui.

The type of Christella boydiae was col-lected "in the valleys of Oahu, 80-100 feet [24.5-30.5 m] above the sea," and it was previously known from the banks of the "Wailuku river, Hilo" on Hawai 'i (elevation not recorded). This fern may once have had a much wider distribution along streambeds from near sea level to 1,350 m elevation, but because of habitat alteration, the remaining plants survive only at the extreme upper margins of its previous haunts.

Christella boydiae may be distinguished by its presence on the periodically inundated ledges of streams, its small size, the somewhat irregularly joining together of the veins (as compared with the regular patterns seen in other species of Christella), and the obtuse tips of its small pinnae.