These were studied by environment, morphology, and cytological analysis of the chromosomes, resulting in the classification of 7 racial complexes, 45 races and hundreds of agro-ecotypes.
Elysia serca also bears great similarities to Elysia catulus (Gould, 1870), a species with a more northerly distribution, and Jensen (1983) considers that E. serca may be a subspecies or ecotype of E. catulus.
Like several of its close relatives (e.g. Fenestraria) and other plants in its ecotype (e.g. some species of Haworthia and Bulbine) it has leaf-windows as an adaptation to the difficulties of photosynthesis in its arid environment.