Martha Washington geranium

Pelargonium /ˌpɛlɑrˈɡoʊniəm/[1] is a genus of flowering plants which includes about 200 species of perennials, succulents, and shrubs, commonly known as scented geraniums or storksbills. Confusingly, Geranium is the correct botanical name of a separate genus of related plants often called Cranesbills. Both Geranium and Pelargonium are genera in the Family Geraniaceae. Linnaeus originally included all the species in one genus, Geranium, but they were later separated into two genera by Charles L’Héritier in 1789. Gardeners sometimes refer to the members of Genus Pelargonium as "pelargoniums" in order to avoid the confusion, but the older common name "geranium" is still in regular use, and most garden 'geraniums' are in fact 'pelargoniums', as opposed to true geraniums or cranesbill.

Species of Pelargonium are evergreen perennials indigenous to Southern Africa and are drought and heat tolerant, and can tolerate only minor frosts. Pelargoniums are extremely popular garden plants, grown as annuals in temperate climates. -- Wikipedia