PATTERNS IN NATURE: DATURA SEED PODS

In places the dry winter veld shows up patches of the skeletal remains of the Datura plants that ripened during the autumn months. The spiky green fruits have since dried, split open and scattered their highly toxic seeds that will spawn new plants once the spring rains have arrived.

DATURA

A widespread weed in South Africa, Datura, grows mainly in places where the soil has been disturbed, such as along roadsides, seasonal river courses, as well as in cultivated lands. We grew up knowing it by the Afrikaans name of Stinkblaar (Stinking Leaves) although I later discovered its English common name is Thorn Apple – at least two varieties commonly occur here: the Large Thorn Apple (Datura ferox) – also known as the Fierce Thorn Apple – and the Common Thorn Apple (Datura stramonium). I find it interesting that the Afrikaans name focuses on the leaves (which produce an unpleasant smell when crushed), while the English name points to the fruit. The genus name Datura comes from the Bengali name ‘dhatura’ for the plant, while the species name ferox means ‘strongly fortified’ and refers to the long spines on seed pods. The seeds of both are poisonous, so it was a plant we were warned from early on to avoid.

The spiny fruit houses the highly toxic kidney-shaped seeds. The photograph below shows the green fruit. This later hardens and dries to a dark brown before splitting open to reveal the black seeds. The Common Thorn Apple is also known colloquially in this country as malpitte (crazy seeds). All parts of Datura plants are poisonous and may prove fatal if ingested by humans as well as livestock and pets as they affect the central nervous system.

The white to creamy-coloured flowers are trumpet-shaped. The petals sometimes show a violet tinge.

This annual belongs to the Solanaceae – or deadly nightshade – family. Although these plants have become naturalised over most tropical and warm temperate regions, they are thought to have originated from the tropical regions of Central and South America. Datura stramonium is one of the world’s most widespread poisonous weeds and it competes aggressively with crops in the field and pasture. It is listed as a noxious weed in South Africa.

 

SILVER LEAF BITTER APPLE

From the time I can remember, we were warned not to touch, never mid eat, the delicious looking shiny yellow globose berries of what we called ‘snake apples’ – an epithet that drummed into us that these enticing berries are poisonous. For years I held a private belief that it must have been an apple like this that Eve ate in the Garden of Eden. Growing up as I did in the Lowveld, the only ‘real’ apples I saw came in a box individually wrapped in squares of purple tissue paper – that was a long time ago.

The Silver-leaf Bitter Apple or Silver-leaf Nightshade (Solanum elaeagnifolium) is most aptly named Satansbos in Afrikaans (the bush of Satan – so our calling it a snake apple wasn’t far off) and the fruits are indeed toxic. Originating in the south-western parts of the United States of America and northern Mexico, it is a weed that has proved to be particularly difficult to get rid of because of its spreading root system. The earliest record of this plant in the National Herbarium is dated 1952.

In the photograph above, you can see the wavy linear to oblong leaves folded upwards along their midribs, as well as the attractive looking fruit. The sharp-eyed among you might also recognise the tiny yellow seed heads of Blackjacks in this photograph too – another invasive weed!

LANTANA CAMARA

As pretty as these flowers are, the Lantana camara (also known as Tick-berry) has long been declared a noxious weed in South Africa. The flowers are attractive to butterflies and the purple-black berries are relished by birds – the latter are responsible for dispersing the seeds far and wide.

Having spent much of my youth on a farm, I was aware that my father got rid of these plants whenever he saw them as they are particularly poisonous for cattle. It was thus with reluctance that I rid our garden of them soon after our arrival.

This plant was growing in a ditch next to the road. I have noticed a number of others blooming along the road leading towards Port Alfred and wonder who is responsible for their removal. One would imagine this would fall within the bailiwick of the Roads Department, on the other hand it is surprising that stock farmers leave them growing on the perimeters of their properties.