Geranium is a genus of 422 species of flowering annual, biennial, and perennial plants that are commonly known as the cranesbills. It is found throughout the temperate regions of the world and the mountains of the tropics, but mostly in the eastern part of the Mediterranean region. These attractive flowers will grow in any soil as long as it is not waterlogged. Propagation is by semi-ripe cuttings in summer, by seed, or by division in autumn or spring.
The genus name is derived from the Greek γέρανος, géranos, or γερανός, geranós, crane. The long, palmately cleft leaves are broadly circular in form. Their rose, pink to blue or white flowers have 5 petals.
The name "cranesbill" derives from the appearance of the fruit capsule of some of the species. Species in the Geranium genus have a type of mechanism produced by the pollinated flower. The mechanism is a beak-like column that springs open when ripe and casts the seeds some distance. The fruit capsule consists of five cells each containing one seed, joined to a column produced from the center of the old flower. The common name cranesbill comes from shape of the unsprung column, which in some species is long and looks like the bill of a crane. Many species in this genus do not have a long beak-like column.
Cranesbills are eaten by the larvae of some Lepidoptera species including Brown-tail and Mouse Moth.
The species Geranium viscosissimum is considered to be protocarnivorous.
Confusingly, "geranium" is also the common name of members of the another genus Pelargonium in the Geraniaceae family, commonly known as 'storksbill' in distinction from 'cranesbill'. Linnaeus originally included all the species in one genus, Geranium, but they were later separated into two genera by Charles L’Héritier in 1789.
In the United States, true Geraniums are frequently distinguished from the less hardy Pelargoniums (generally grown as annuals in temperate climes) as (rather redundantly) "hardy geraniums" by gardeners and in the horticultural trade. Most garden 'geraniums' are in fact 'pelargoniums' (storksbill), as opposed to true geraniums (cranesbill). 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, e.g. 'scented geranium'.
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