In 50 to 60 million years cycads have changed very little and as such are often referred to as ‘living fossils’. The word cycad is derived from the Greek word ‘cyckos’ meaning palm-like and they are often confused with palms and tree ferns, but in fact are unrelated. Cycads belong to a group of plants called gymnosperms (meaning ‘naked seeds’) where the reproductive organs are produced in cones and not flowers as in other species.
These cones are the part of the plant that has poisonous properties. The seed kernels are highly toxic while the pulp around the seeds is generally considered non-toxic, but could have trace elements of the toxins cycasin and macrozamin. The amount of these toxins will differ from species to species. Cycads are listed in the top ten plants most commonly responsible for poisonings recorded by hospitals in South Africa. Symptoms of poisoning include vomiting, diarrhoea, headaches, dizziness and seizures. The toxins are known to cause severe liver damage in humans and are also carcinogenic. A case of poisoning occurred during the Anglo-Boer War of 1899-1902 when nearly 70 men including General Jan Smuts and two of his lieutenants fell ill after eating fruit from ENCEPHALARTOS longifolius (Zuurberg Cycad). General Smuts was said to have been extremely ill and this incident is regarded by some as a turning point in his personal military strategy in the Cape.
The bright orange to red cones attract many animals including baboons, vervet monkeys, dassies, fruit bats and birds. After eating the fleshy covering, the animals spit out the poisonous kernels and disperse the seeds. In South Africa cycad stems have in the past been used as a food source, hence the Afrikaans name for cycads ‘broodboom’ (bread tree). The pith was removed from the stems, tied up in an animal skin, fermented and then ground into a meal.
All cycads in South Africa are now protected by law and the trade in cycads is strictly controlled due to over-collection from the wild in the past.
Return to the top of Cycads