Alkaloids are common in the Angiosperms (Mono- and
Dicotyledons), but rare in lower plants, although there are
exceptions, for example pacletaxel from yew(a Gymnosperm),
lycopodine [XXXII] from Lycopodium and palustrine
[XXXIII] from Equisetum (both Pteridophytes), and
even fungi, e.g. ergometrine (Claviceps). These structures
are shown in Figure 1. The distribution of alkaloids in the
plant kingdom is listed in Table 1.