琉球蕗蕨 liu qiu lu jue

?Hymenophyllum taiwanense (Tagawa) C. V. Morton; Mecodium riukiuense (Christ) Copeland; ?M. taiwanense Tagawa.

Plants 6-15 cm tall. Rhizome ca. 0.5 mm in diam., laxly branched. Stipes remote, 2-6 cm, hairy at base, glabrous upward, winged throughout, wings sharply crisped. Lamina tripinnate to quadripinnatifid, oblong-subdeltoid, 4-7 × ca. 4 cm, glabrous, apex acute to moderately acute; pinnae 5-10 pairs, basal ones oblong-subdeltoid, base broadly cuneate to rounded, stalked, apex moderately acute to rounded; upper ones gradually smaller upward, oblong; ultimate segments narrow, ca. 4 × 0.6-1 mm, decurrent into every axis forming distinct, wavy or crisped wings ca. 0.8 mm, margin entire but crisped, apex rounded to obtuse. Sori usually on upper parts of pinnae; involucres subdeltoid to oblong, 1.2-1.6 × ca. 1 mm, lips finely toothed; receptacles usually included.

On moss-covered tree trunks in dense tropical evergreen forests; common at middle or higher elevations. Hainan, ?Taiwan [Japan, Thailand].