Chrysosporum ovalisporum is synonymous with the true-branching cyanobacterium Umezakia natans (Nostocales/Aphanizomenonaceae).

True branching is a facultative characteristic only known from two cyanobacteria in the Aphanizomenonaceae, Umezakia natans and Dolichospermum brachiatum. In both cases, its expression has been associated with environmental stress, and its practical use as a diacritical feature has been previously evaluated. In this study, we undertook further evaluation of the phylogeny of Umezakia natans and its relationship to Chrysosporum ovalisporum as a previous study suggested the two were potentially congeneric.