Rust is a disease of the leaves of zonal pelargoniums, caused by the fungus Puccinia pelargonii-zonalis. This is a disease specific to zonal pelargoniums. Ivy-leaved pelargoniums are not affected.
The South African geranium (Pelargonium sidoides) is an herb traditionally used in South African medicine to treat gastrointestinal conditions and later brought to Europe as a tuberculosis treatment.
Leaves may be mid-green (Regal and Angel) or marked in maroon zones (Zonal). Pelargoniums must have soil that drains easily and generally prefer full sun. Regals are best in partial shade. In ...