Pelargonium sidoides

African geranium forms a basal rosette of cordate leaves with a velvet texture and a few short trichomes on long petioles.[1] Its flowers have five dark red to nearly black petals, two of which are sometimes fused. It is often found in flower nearly year-round. It prefers to grow in grasslands with rocky soils. It can be difficult to distinguish from Pelargonium reniforme which grows in a similar area, but tends to have more kidney-shaped leaves.

In cultivation in the UK, Pelargonium sidoides has received the Royal Horticultural Society's Award of Garden Merit.[2] If grown as a perennial it requires protection in winter, as it does not tolerate temperatures below 5 °C (41 °F). It needs a sunny, sheltered position.

A 2013 Cochrane review found limited to no evidence of benefit with Pelargonium sidoides root extract for the symptoms of acute bronchitis, the common cold and acute rhinosinusitis.[3] A summary of this review found that all studies were "from the same investigator (the manufacturer) and performed in the same region (Ukraine and Russia)."[3]

Root extract of Pelargonium sidoides may be sold as a dietary supplement or traditional medicine under various brand names, including Umckaloabo and Zucol, but there is limited high-quality clinical evidence it provides any benefit.[4]