Parietochloris ovoideus sp. nova (Trebouxiophyceae, Chlorophyta), a new aerophyte alga from Ukraine

Mophology of Parietochloris ovoideus MIKHAILYUK et DEMCHENKO sp. nova, found at first from air samples collected among granitic outcrops of the Steppe zone of Ukraine, as well as material from chasmoendolithic and epiphytic algal groups of the same locality, was studied under the LM and in cultural conditions. This species differs from all other species of this genus by the shape of vegetative cells, morphology of chloroplast, shape of zoospores and the number of zoo- and aplanospores in sporangia. Latin diagnosis, description, illustrations, data on age stages and life cycle of the new species are present. The morphological characters of P. ovoideus are compared with all known species of genus Parietochloris.