Common names: kikawaio, kikawaioa, pakika-waio (P. & E.)

Endemic

Specific name from Cyathea, a tree fern genus,+ -oides, resembling, implying a similarity in appearance between the two.

Plants variable in size, usually with large fronds. Rhizomes erect to decumbent, thick, usually more than 3 cm diam., interior of various colors from white to yellowish or purple when cut. Fronds erect, 25-200 cm long, may be fertile even when short. Stipes glabrous except at base. Blades 1-pinnate, linear-lanceolate, mostly glabrous, sometimes with scattered glands or hairs, tips of fronds similar to lateral pinnae. Pinnae 18-26 pairs, short-stalked, lanceolate to linear, sometimes falcate, 7-30 x 0.8-4.5 cm, margins entire to moderately lobed, basal pinnae same size or sometimes smaller than middle pinnae, tips acute. Veins pinnate, minimally or not raised, 3-10 veins anastomosing below sinuses, forming excurrent veins to sinuses. Sori 3-8 on both sides. Indusia large, small, or absent, reniform or peltate.

Found in habitats ranging from forest floors to steep, shaded slopes, on vertical rock walls, often near stream banks and waterfalls, and rocks and ledges along streams, 120-1,400 m, all major islands.

Although the species is extremely variable- the fronds may be large or small; the rhizomes creeping and slender to thick and erect (up to 1.5 m tall); rhizome interiors purple to yellow or white; pinnae entire or occasionally lobed; the sori indusiate or ex-indusiate there is little difficulty in recognizing it. A thorough study is needed to clarify its status as a single species or a complex of several species or varieties.

One variant from Kaua'i has been named Cyclosorus exindusiata, but differs only in its exindusiate sori and rhizome color. These characters fall within the known range of variation of this species.

Christella cyatheoides hybridizes with the naturalized C. dentata to form a sterile but widespread hybrid. (See discussion under Hybrids later in this genus treatment.)

Ancient Hawaiians ate the roots and young fronds raw or grated and salted them to add taste in a preparation that was slimy like okra. Christella cyatheoides was also considered an herb of medicinal value.

Although variable in size, Christella cyatheoides may be distinguished by its acute-tipped, 1-pinnate fronds with gla· brous-appearing, somewhat shiny, smooth, light green blades, pinnate veins, and blade tips that resemble the lateral pinnae. Its veins have 3-10 branches joining to form excurrent veins extending to shallow sinuses at the margins.

Pneumatopteris sandwicensis appears similar to C. cyatheoides, but may be distinguished from it by the presence of abun· dant short, fine hairs on the rachises, mid ribs, and upper surfaces of the pinnae; a darker green color; and generally rougher pinnae surfaces. Its frond tips are pinnatifid; those of C. cyatheoides are similar to the lateral pinnae.