Sargassum plagiophyllum C. Agardh, 1824: 304–305 (type locality: "In mari Indico'').—J. Agardh, 1848b: 309.— Kützing, 1849: 613.— G. Martens, 1868: 74–75.— J. Agardh, 1889: 120, pl. XII: figs. 4, 5.— Reinbold, 1891b: 73.— De Toni, 1895b: 105–106.— De Wildeman, 1897a: 159.— Reinbold in Weber-van Bosse, 1913a: 166.— Grunow, 1916 [1915–1916]: 9.— Børgesen, 1933a: 15, pl. 5.— S. Dixit, 1940a: 95.— Levring, 1943: 178.— Biswas & Sharma, 1950: 96.— Chacko, Mahadevan, & R. Ganesan, 1955: 12.— Thivy, 1964: 27.— S. Dixit, 1966: 10.— Misra, 1966b: 183, fig. 98.— Misra, 1967: 233.— K. Srinivasan, 1967: 146, fig. 48.— V. Krishnamurthy & H. Joshi, 1970: 14.— Raju & Venugopal, 1971: 36–38, figs. 1–4, table 1.— Dhargalkar, Jagtap, & Untawale, 1980: table 2.— Untawale, Dhargalkar, & Agadi, 1983: [23].— Subbaramaiah, 1985: 140.— Padmini Sreenivasa Rao, Sreenivasa Rao, & Karmarkar, 1986a: 6–8.— Padmini Sreenivasa Rao, Sreenivasa Rao, & Karmarkar, 1986b: 25, table 1.— Silas & Kalimuthu, 1987: 56.— Padmini Sreenivasa Rao, Sreenivasa Rao, & Karmarkar, 1988a: 295.— Padmini Sreenivasa Rao, 1989a: 24, table 1.— Pant & Untawale, 1989: table 4.— V. Krishnamurthy et al., 1990: 271.— Padmini Sreenivasa Rao, Sreenivasa Rao, & Karmarkar, 1991: 15, table 1.— Bhakuni et al., 1992: 515.— Kalimuthu, Kaliaperumal, & Ramalingam, 1992: 122.— V. Kumar, 1993a: 139, 140.— V. Kumar, 1993b: 47.— V. Kumar et al., 1993: 23.— Rama Rao et al., 1993: 106.
INDIAN OCEAN DISTRIBUTION: India, Indonesia (Flores and Sumatra), Singapore, Sri Lanka.