Pelargonium is a genus of flowering plants which includes about 200 species of perennial, succulent, and shrub plants, commonly known as geraniums. Confusingly, Geranium is the correct botanical name of the separate genus which contains the related Cranesbills. Both genera are 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. (from Wikipedia)
I don't know about you, but for years I thought the pretty annual red and pink flowering plants that you put in planters and borders were the only geraniums that existed. Then I read an article in a gardening magazine about ten years ago and learned about both types. I always now call cranesbills perennial geraniums and the ones pictures above "just geraniums". These geraniums now come in so many different colors and gardeners can plant Martha Washingtons, ivy, or just geraniums. Our geraniums work well for us because we bring them in each fall and winter them over. We also propagate them for new plants, and enjoy them year round. Each year we try to find a few new or unique types and colors. They are the easiest plants to propagate with some healthy cuttings, some root hormone, and potting soil.
If you haven't grown scented geraniums, they are a treat in any garden. When the leaves are scratched they have the scent of rose, mint, lemon, or other lovely smells. They are said to deter mosquitoes, but I don't know if that is true for sure. We have lots planted around, but we have never had too many of those pesty bugs before. Maybe I should take a plant camping and see if it really does work. Cranesbills are a good choice as a border plant because they spread and have pretty blue or purple flowers in summer.
Just geraniums also seem to be a plant right now in the hot, hot weather that are hanging in there with blooms still opening. Whatever kind you have or whatever name you give them- geraniums are a perfect addition to any garden.