Geraniums - Commonly known as Cranesbills.
The genus Geranium (from the Greek geranos, a crane - referring to the rostrum of the schizocarp; resembling the bill of a crane) encompasses about 400 species. Whilst there are a few woody shrubs most are perennial and annual herbs some of which unfortunately, are introduced weeds.
When ripe, the seeds of Geraniums dehisce by 'expulsion' from the capsules - away from the parent plant.
Not to be confused with the genus Pelargonium (many of whose brightly coloured flowers are incorrectly referred to as 'geraniums' by the average gardener, and still so labelled by commercial growers who should know the difference) the five petalled flower structure in Geranium is regular or actinomorphic. That is to say it is divisible into two or more planes with similar halves.
As cultivated garden plants, many Geraniums are memorable for their striking mounds of foliage as well as some charmingly simple flowers in a range of colours that includes white through pink, magenta, purple and the all-desirable blue.