Sargassum tenerrimum J. Agardh var. ambiguum Grunow, 1915 [1915–1916]: 370–371 (`ambigua') (type locality: Cannanore, Kerala, India).—K. Srinivasan, 1965: 243.— K. Srinivasan, 1967: 148, fig. 12.— V. Krishnamurthy & H. Joshi, 1970: 15.
INDIAN OCEAN DISTRIBUTION: India.