Pelargonium sidoides

This geranium native to southern Africa, and is often known as Umckaloabo. A common preparation is Umcka, which was first used and marketed in Europe and is now sold in the U.S. under the Nature's Way brand.
Its most common application is the treatment of upper respiratory infection, from the common cold to bronchitis and pneumonia. Because it is generally well-tolerated and has a good amount of specific research behind it, many often recommend it for children.
Phytomedicine has just released a supplement to its regular issues that reviews some of the most recent research on this remarkable plant. Here is a quick roundup:

EPs® 7630, an extract from Pelargonium sidoides roots inhibits adherence of Helicobacter pylori to gastric epithelial cells


Fascinating metabolic pools of Pelargonium sidoides and Pelargonium reniforme, traditional and phytomedicinal sources of the herbal medicine Umckaloabo®

In vitro evaluation of antibacterial and immunomodulatory activities of Pelargonium reniforme, Pelargonium sidoides and the related herbal drug preparation EPs® 7630

Inhibition of lipopolysaccharid-induced sickness behavior by a dry extract from the roots of Pelargonium sidoides (EPs® 7630) in mice

Mass spectroscopic characterisation of oligomeric proanthocyanidins derived from an extract of Pelargonium sidoides roots (EPs® 7630) and pharmacological screening in CNS models

Treatment of rats with the Pelargonium sidoides extract EPs® 7630 has no effect on blood coagulation parameters or on the pharmacokinetics of warfarin

Extract of Pelargonium sidoides (EPs® 7630) improves phagocytosis, oxidative burst, and intracellular killing of human peripheral blood phagocytes in vitro

Extract of Pelargonium sidoides (EPs® 7630) inhibits the interactions of group A-streptococci and host epithelia in vitro

Treatment effect and safety of EPs® 7630-solution in acute bronchitis in childhood: Report of a multicentre observational study

EPs® 7630-solution - an effective therapeutic option in acute and exacerbating bronchitis

Pelargonium sidoides preparation (EPs® 7630) in the treatment of acute bronchitis in adults and children

Liquid herbal drug preparation from the root of Pelargonium sidoides is effective against acute bronchitis: Results of a double-blind study with 124 patients

Some issues: the patented liquid preparation, for one. This is a "1X homeopathic dilution of an alcohol extract of Pelargonium". I tend to prefer whole-plant administrations that are traditionally prepared. Also, the large amount of in-vitro and animal studies. Nevertheless, there is some good data on this plant and more is becoming available. As modern medicine continues its shift away from the overuse of antibiotics in respiratory infection, this herb seems to be a helpful adjunct to the tried-and-true diaphoretics and immunomodulators herbalists have been using. I will try to grow it this summer, and see if I can overwinter it in my heated greenhouse...