Note: Information is dated. Do not rely on it.Geranium. A genus of plants embracing a large number of species unequally distributed throughout the world. The well-lmown herb, Robert (Geranium Robertianum), is a low, spreading weed, a rank-odored plant, common on rocks, where its soft, compound, fern-like leaves, and little pink flowers are very attractive. The plants usually known as geraniums belong to the genus Pelargonium, of the same order as the geranium. These plants are prized on account of the colors of the flowers, and the shape and marking of the leaves. Many hybrids have been produced and there is hardly a better known window plant. They are easily propagated by cuttings in light, rich soil and with good drainage.