Abstract:
Fadogia homblei, Pavetta harborii, Pavetta schumanniana, Vangueria pygmaea (=Pachystigma pygmaeum),
Vangueria latifolia (=Pachystigma latifolium) and Vangueria thamnus (=Pachystigma thamnus) all induce
one of the most important cardiotoxicoses of domestic ruminants in southern Africa, causing the sickness
gousiekte. All the plants which cause gousiekte have previously been shown to contain bacterial endophytes.
However, in this study other plants within the Vanguerieae tribe that have not been reported to cause
gousiekte; namely Vangueria infausta, Vangueria macrocalyx and Vangueria madagascariensis, have now
been shown to also contain endophytes within the inter-cellular spaces of the leaves. The disease gousiekte
is difficult to characterise due to fluctuations in plant toxicity. The majority of reported cases of gousiekte
poisoning are at the beginning of the growing season; and thus the plants are thought to be more toxic at
this time. By using both transmission and scanning electron microscopy the endophytes within these
Vanguerieae plants were compared visually. Using the plant reported most often for gousiekte poisoning,
V. pygmaea, a basic seasonal comparison of the presence of endophytes was done. It was found that the
bacterial endophyte colonies were most abundant during the spring season.
