1. Burke, F., NATURE, 150, 610 (1942).
2. Sherlock, Mem. Geol. Survey, "Mineral Resources of Great Britain, Rocksalt and Brine", 18, 54 (1921).
3. Kew . No Herbarium record.
4. Biological Abstracts back to 1927.
5. Tilden's "Index Algarum Universalis".