Dictyopteris undulata

Thallus flat, coriaceous, smooth, 10–25 cm high, yellowish-brown to olive-brown with a bluish iridescence under water, on long subcylindrical stipe (stupose in older plants) bearing irregularly dichotomously branched blades. Blades rugose, 0.6–1.5 cm broad, with well visible percurrent midrib, membranous undulate wings and broad-obtuse apices. Short terminal branches also with prominent midrib. Sporangial sori arranged along the midrib on both sides of the blades in the upper portion of old thallus. Attachment by conical holdfast, covered with brownish hairs. Growing on rock, below low-tide mark to subtidal on open coasts.

North and Central America. Сountries of the Asia-Pacific Region: China, Japan, Korea, Taiwan.