5. Zostera japonica Ascherson & Graebner in Engler, Pflanzenr. 31(IV. 11): 32. 1907.
矮大叶藻 ai da ye zao
Nanozostera japonica (Ascherson & Graebner) Tomlinson & Posluszny.
Rhizomes creeping, 0.5-1.5 mm in diam., internodes 0.5-3 cm. Leaves on non-flowering shoots 2-4, linear, 5-35 × 1-2 mm, 3-veined, apex obtuse or retuse; sheaths open, 2-10 cm, margin membranous; auricle obtuse, ca. 0.5 mm; intravaginal squamules 2, lanceolate. Flowering stems 10-30 cm; spathes with flattened stalk, ca. as broad as or narrower than leaves, apex obtuse, mucronate, rarely retuse; spadix with projections. Anthers ca. 2 mm. Ovary ca. as long as style; stigmas subulate. Fruit ellipsoid to narrowly cylindric, ca. 2 mm. Seeds smooth. Fl. and fr. Jun-Sep. 2n = 12.
Bottoms of shallow seas. Coasts of Hebei, Liaoning, Shandong, Taiwan [coasts of Japan, Korea, Russia (Far East), Vietnam; Africa, Asia, Europe, North America].