Eponymy: named for Ralph Arnold Lewin, "who collected the original soil sample from the Easter Islands, from which the strain was isolated."
Type locality: Easter Island, Chile. Permanent freshwater pond in a crater.
Holotype: Material of the authentic strain CCAP 211/90 is cryopreserved at the Culture Collection of Algae and Protozoa, Oban, Scotland. Isotype: An air-dried as well as a formaldehyde-fixed sample of strain CCAP 211/90 was deposited at the Botanical Museum at Berlin-Dahlem under the designation B40 0040663.