A chemotaxonomic reappraisal of the Section Ciconium Pelargonium (Geraniaceae)

The section Ciconium Pelargonium (Geraniaceae) was reappraised using alkaloid patterns as the main chemotaxonomic marker. The results indicate that several species recently reallocated from other sections do not comply with the chemotaxonomy of the original Ciconium (Sweet) Harv. members. These include P. alchemilloides, P. quinquelobatum, P. elongatum, P. multibracteum and P. transvaalense (late of Eumorpha). P. caylae, P. mutans, P. tongaense and P. peltatum (the last lately of Section Dibrachya) do not comply either. The only Ciconium species with the characteristic alkaloids are: P. zonale, P. inquinans, P. acraeum, P. scandens, P. frutetorum, P. salmoneum and P. ranunculophyllum. P. × hortorum cultivars, which are derived from some of these species, also show the characteristic alkaloid pattern. The results support a divergence in the section Ciconium, based, with some exceptions, on geographical distribution, giving rise to a subsection with alkaloids, found mainly in the Western Cape Province and a subsection without alkaloids, extending to east and north-east Africa, Ethiopia and Madagascar