In a lab at Wits University, aliens are being grown and nurtured to test if they are going to become the vanguard of an invasion.
Amy Burness’s lab is a greenhouse and it is here where she grows the seeds she collects on her trips around Joburg.
The seeds are alien species and they have come from across the world.
So far the Master’s student, at the university’s animal, plant and environmental sciences department, has identified 216 plant species that have been brought into South Africa
by migrant populations.
The majority - 134 of them - came from China.
To find these plants she visited muti markets, herbalist shops and the odd restaurant where the owners sell medicinal remedies to make a little extra on the side.
“I was this little white girl running around markets in the middle of Yeoville and I got the reaction of: ‘Are you lost? Why are you here?’,” says Burness.
It is the smallest seeds that are the bigger threat, because their size allows them to fall out of bags, or simply get disregarded and, if the conditions are right, set up home.
And some of these seeds, Burness has noticed, do like Joburg’s moderate climate. One of these is the black seed, also known as fennel flower, which comes from Asia.
“It took me a month to grow black seed and if you consider summer is six months, you could have six generations of the plant growing in that time,” Burness explains.
As part of her research she takes some of the seeds she collects and grows them in the greenhouse set up to mimic Johannesburg conditions.
Black seed is one of hundreds of plants that have come into South Africa carried by the post-1994 migrant influx.
Many of these plants are used not only for medicine, but also for cooking and even as beauty products.
The problem is that no one knows if these alien species are a threat to the indigenous flora.
“A measure that we use to see if it will become invasive in South Africa is to see if it is invasive elsewhere in the world,” the department’s Professor Marcus Byrne explains.
“But we don’t want to appear alarmist, we just want to raise a flag on this.”
Burness has found that the majority of these alien plants come from China, India, Nigeria and the Congo.
Plants from the Congo, Burness discovered, usually arrive in Joburg by truck or car. The seeds from Nigeria, China and India come by freight, or are sometimes flown in.
The traders don’t appear to have hassles getting their plants through the border.
“A lot of the Somalian ladies get their facial care products, which are ground herbs, from Nairobi. Someone drives up there and fills up a bakkie.”
There have been some surprises. Burness found that some Indian traders got their produce not from India, but from Canada, where it is grown on the prairie.
“Something like 45% of what I found is for man power (virility),” she laughs.
This is not the first time that immigrants have introduced new plants to South Africa.
Thousands of years of trade along the east coast of southern Africa may have introduced dagga and even the willow tree.
“There is a big conflict of interest with medicinal plants in that for us it is an alien species, but on the flip side they are really culturally important. It gives immigrants a sense of cultural identity,” she says.
But Burness will continue growing aliens in her lab, so she can keep an eye on the ones that might decided to take root and settle down.