Geranium robertianum

Geranium robertianum, commonly known as herb-Robert, or (in North America) Roberts geranium, is a common species of cranesbill native to Europe and parts of Asia, North Africa, and parts of North America. The plant has many vernacular names, including red robin, death come quickly, fox geranium, stinking Bob, squinter-pip (Shropshire) and crow's foot.

Description
It grows as a procumbent (prostrate or trailing) to erect annual or biennial plant, up to fifty centimetres high, producing small, pink, five-petalled flowers (8–14 mm in diameter) from April until the autumn. The leaves are deeply dissected, ternate to palmate, the stems reddish and prominently hairy; where it grows in sunny sites, the leaves also turn crimson red at the end of the flowering season.

Distribution and habitat
Its main areas of distribution are Europe from the north Mediterranean coast to the Baltic, from the British Isles in the west to the Caucasus in the east, and eastern North America. It is not native to western North America, where it has escaped from cultivation and is regarded as an invasive species. Geranium robertianum is common throughout Great Britain and Ireland in woodland, hedgerows, scree and maritime shingle. It grows at altitudes from sea level to 710 m in Teesdale, England and above 2100 m in parts of mainland Europe on calcareous alpine screes.

Uses
Herb Robert has been used in the folk medicine of several countries, including as a treatment for diarrhea, to improve functioning of the liver and gallbladder, for toothache and nosebleeds, and as a vulnerary (used for or useful in healing wounds). Its common name has several possible sources: the Latin word for red, ruber; Shakespearean character Robin Goodfellow, the mischievous hobgoblin in A Midsummer Night's Dream; an early duke of Normandy named Robert who is rumored to have commissioned the Regimen sanitatis Salernitanum; or abbot and herbalist Robert of Molesme. Freshly picked leaves have an odor resembling burning tires when crushed, and if they are rubbed on the body the smell is said to repel mosquitoes.

Chemical constituents include tannins, a bitter compound called geraniin, and essential oils.