Taxonomy of the genus Pelargonium (Geraniaceae): The section Polyactium 3. The subsection Polyactium
The subsection Polyactium of the genus Pelargonium (section Polyactium) is treated taxonomically in view of currently available information. All species are geophytes with massive, naked underground tubers. Seven species are recognized, which have almost identical flowers but differ greatly in respect of the morphology, texture, and indumentum of the leaves. All share a basic chromosome number of x = 11; but polyploidy of up to hexaploid level occurs, with each species tending to have a characteristic level of ploidy. Six of the species are restricted to the winter rainfall area, while the seventh occurs in the winter rainfall area but also extends quite far into the summer rainfall region.