ABSTRACT
There have been few chemotaxonomic studies of the genus Pelargonium and the results of studies on tannins and flavonoids (Asen and Grisbach, 1983; Bate-Smith, 1973, 1981; Marszewski, 1990) and unidentified phenolic compounds (Harney, 1966, 1976) were of limited value in the allocation of species into sections. Other components studied included tartaric acid (Stafford, 1961), which proved to be unsatisfactory as chemotaxonomic indices. Essential oils were studied in Pelargonium species and cultivars by Demarne and van der Walt (1989), Lis-Balchin (1991), Lis-Balchin et al. (1998a,b) and Lis-Balchin and Roth (1999) and proved of value in classification, but only according to odour. The detection of alkaloids in some Pelargonium species suggested that this criterion could be used as a chemotaxonomic marker (Lis-Balchin, 1993, 1996). Prior to the latter work, alkaloids had only been detected in some Erodium species (Medina et al., 1977; Mossa et al., 1983; Lis-Balchin and Guittonneau, 1995).
