二药藻 er yao zao

Zostera uninervis Forsskål, Fl. Aegypt.-Arab. 157. 1775; Diplanthera uninervis (Forsskål) F. N. Williams.

Internodes of rhizome 2.5-3(-5) cm. Scales elliptic, membranous. Leaves narrowly linear, 4-11(-15) cm × 0.8-1.4 mm, veins 3, midvein conspicuous, basally gradually narrowed, lateral teeth conspicuous, apex trifid; sheaths 2-3 cm. Flowers small. Peduncle of male flowers 1-2 cm; anthers ca. 0.5 mm. Style of female flowers 3-4 mm, apical. Fruitlet ovoid, ca. 2.5 × 2 mm; beak apical, ca. 1 mm.

Marine shallow sandy bottoms. Hainan, Taiwan [India, Indonesia, Japan (including Ryukyu Islands), Malaysia, Myanmar, Philippines, Sri Lanka, Thailand, Vietnam; Africa, SW Asia, Australia; W Pacific Ocean and Indian Ocean to Red Sea].