A new Sphaerellocystis (Palmellopsidaceae, Tetrasporales) from Prairie soils

The unicellular green alga Sphaerellocystis has been studied in bacterized as well as axenic cultures. An isolate from enriched prairie soil samples has been compared to all validly described species within the genus. The authors have found no coincident groups of characteristics which would allow assigning this isolate to a previously described taxon. Therefore, we have described the organism as Sphaerellocystis aplanospora sp. nov. Additionally we have studied certain physiological, biochemical and ultrastructural attributes of the isolate. These should be useful as supplementary characteristics for the genus and its species as other species are isolated and cultured for meaningful comparative evaluation of the entire genus and apparently related genera.