日本阴地蕨 ri ben yin di jue

Sceptridium nipponicum (Makino) Holub.

Plants small, winter-green. Rhizomes erect, short, cylindrical, annually producing 1 frond 20-50 cm tall. Sterile lamina: stalk 4.5-19 cm, glabrous; lamina subternate, tripinnate, ca. 10 cm long and wide, herbaceous or membranous, reddish in winter; lower pinnae broadly ovate, long stalked, upper ones much narrower; ultimate segments large, differentiated from lateral pinnules, elongate, 8-15 × 5-10 mm, margin finely serrate, apex acute; veins pinnate, free. Sporophore arising 1.5-6 cm above base of common stipe (or distinctly below middle of common stipe), much taller than sterile lamina, deciduous after spore dispersal; stalk ca. 40 cm; lamina smaller than sterile lamina; sporangia globose, attached on both lateral sides of axes. Spore surface irregularly reticulate with fine granules. 2n = 90.

Forests. Guangxi [Japan, Korea].