Plasmodium ovale
Plasmodium ovale is a species of parasitic protozoa that causes tertian malaria in humans. It is one of several species of Plasmodium parasites that infect humans including Plasmodium falciparum and Plasmodium vivax which are responsible for most malarial infection. It is rare compared to these two parasites, and substantially less dangerous than P. falciparum.
P. ovale has recently been shown by genetic methods to consist of two subspecies, P. ovale curtisi and P. ovale wallikeri.