Chlorogenic acids and caffeine as possible taxonomic criteria in Coffea and Psilanthus

This paper reports the amount of chlorogenic acids, chlorogenic acid-like components, caffeine and other 276 nm-absorbing components in seeds of Coffea and Psilanthus . Twenty species have been grouped according to their seed composition and the groupings compared critically with the existing classification scheme based upon morphology. Concordance is generally good, although classification on seed composition suggests that Coffea subgen. Coffea could be further subdivided and that Psilanthus subgen. Afrocoffea may merit recognition at generic rather than subgeneric level. It also appears that such analyses may provide a better understanding of the morphologically variable taxa such as C. congensis , C. stenophylla and the libero-excelsoides group.