1a. Najas marina var. marina
大茨藻(原变种) da ci zao (yuan bian zhong)
Ittnera major (Allioni) C. C. Gmelin; Najas major Allioni; N. major var. angustifolia A. Braun; N. marina var. angustifolia (A. Braun) K. Schumann.
Stems mostly armed with spines. Leaves with 4-10 conspicuous teeth on margin, abaxial side of midvein with spines ca. 2 mm. Style and stigma 2-3 mm; anthers 3.8-4 mm. Seeds 4.5-5.7 × 2-2.8 mm.
Ponds, lakes, slow-moving rivers; below 2700 m. Anhui, Guangdong, Guangxi, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, Nei Mongol, Shandong, Shanxi, Taiwan, Xinjiang, Yunnan, Zhejiang [India, Japan, Korea, Malaysia, Russia, Tajikistan; Africa, Australia, Europe, North America].